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The Association Between Asthma and GERD (Acid Reflux)

October 10, 2025 | Black & Kletz Allergy

The Association Between Asthma and GERD (Acid Reflux)Individuals with asthma probably are unaware of the association between asthma and acid reflux (GERD). It is estimated that approximately 75% of asthmatics have GERD of some degree. GERD or acid reflux occurs when there is a backflow of stomach contents into the esophagus (i.e., swallowing tube). In other words, the stomach contents travel in the wrong direction and enter the esophagus, instead of the small intestines. People with GERD often complain of “heartburn,” which in reality is a burning sensation in the chest and/or throat usually in conjunction with a sour or bitter taste in the mouth. In addition, some individuals may experience other symptoms which may include sore throat, burping, abdominal bloating, nausea, wheezing, coughing, and/or the sensation that something is caught in one’s throat. It is the wheezing and coughing symptoms that cam mimic asthma in individuals without asthma. In true asthmatics, acid reflux may actually worsen their asthma symptoms, not just mimic them. In patients with asthma, the typical asthma symptoms of chest tightness, coughing, wheezing, and/or shortness of breath may be aggravated if the underlying acid reflux is not treated appropriately. The first way this may occur is via small amounts of acid irritating the airways (similar to a chemical burn) which may in turn cause asthma symptoms. The second method may involve the triggering of a reflex in the airways to become narrower in order to prevent more acid from entering the airways. It is this narrowing of the airways that causes an individual with asthma to cough, wheeze, cough, experience chest tightness and/or feel short of breath. In addition to the 2 methods above, some asthma medications may decrease the lower esophageal sphincter pressure thus relaxing this muscle which in turn will increase the severity of GERD or acid reflux. Asthma medications in the bronchodilator family such as albuterol (i.e., Proventil, ProAir, Ventolin, AccuNeb), terbutaline (i.e., Brethaire, Brethine), vilanterol, ipatroprium (i.e., Atrovent), salmeterol (i.e., Serevent), formoterol, (i.e., Foradil), levalbuterol (i.e., Xopenex), and Tiotropium (i.e., Spiriva) fall into this category. There are also asthma medications that are combinations of two or more medications, one of which is a bronchodilator, which can therefore increase acid reflux disease. The names of some of these medications include Advair, Dulera, Breo Ellipta, Symbicort, Combivent, AIRSUPRA, Trelegy, and DuoNeb. Theophylline (i.e., Theo-Dur, Uniphyl, Slo-Bid, Theo-24), an older but still useful oral bronchodilator asthma medication, has also been associated with an increase in GERD in patients by causing the relaxation of the lower esophageal sphincter as well. Interestingly, the chemical structure of theophylline is similar to that of caffeine which is another trigger of GERD. It is a double edge sword because not only can acid reflux exacerbate one’s asthma, but asthma can also make one’s acid reflux worse. In addition to asthma making one’s acid reflux worse, there are several risk factors that may contribute to GERD and some of them may include obesity, alcohol use, diabetes mellitus, pregnancy, smoking, connective tissue diseases (e.g., systemic sclerosis or scleroderma), eating large meals, eating before bed, hiatal hernia, certain medications [e.g., aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), oral corticosteroids, bronchodilators, calcium channel blockers], and/or certain foods [e.g., caffeine, spicy foods, .garlic, onions, fatty foods, acidic foods (soda, citrus fruits, tomatoes)]. The diagnosis of GERD can be made by performing a comprehensive history from the patient along with observing relief when taking anti-reflux medications such as antacids and/or acid-blocking medications. If there is no improvement in acid reflux symptoms, there are several procedures that can be performed in order to help establish the diagnosis of acid reflux disease. Some of these procedures include upper endoscopy with or without a biopsy, barium swallow, pH monitoring (checks the acidity in the stomach), and esophageal manometry (checks the function of the lower esophageal sphincter and esophagus). The treatment of GERD is directed at reducing the risk factors mentioned above as well as prescribing acid-blocking medications and antacids. By treating the underlying GERD in patients who are asthmatic with associated GERD, the symptoms of asthma (i.e., chest tightness, coughing, wheezing, and shortness of breath) may also be reduced. The board certified allergy doctors at Black & Kletz Allergy have been diagnosing and treating asthma for more than 50 years. We treat both pediatric and adult and patients. Black & Kletz Allergy has offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. All 3 of our offices have on-site parking. For further convenience, our Washington, DC and McLean, VA offices are Metro accessible. Our McLean office location offers a complementary shuttle that runs between our office and the Spring Hill metro station on the silver line. For an appointment, please call our office or alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day. If you suffer from asthma or allergies, we are here to help relieve or hopefully end these undesirable symptoms that have been so bothersome, so that you can enjoy a better quality of life. Black & Kletz Allergy is dedicated to providing the highest quality allergy care in a calm, compassionate, and professional environment.
Allergy Nasal Spray Prevents COVID?

September 26, 2025 | Black & Kletz Allergy

Allergy Nasal Spray Prevents COVIDSARS-CoV-2 is the name of the coronavirus that is responsible for the COVID-19 pandemic that caused millions of deaths worldwide.  Although vaccination and established population immunity have substantially mitigated the severity of acute SARS-CoV-2 infections, the virus continues to infect millions of people resulting in a number of hospitalizations and deaths.  There is a need for an effective pre-exposure prophylaxis for the general population, particularly for high-risk groups such as individuals with preexisting conditions and the elderly. Azelastine is a second-generation antihistamine, which is commonly used as a nasal spray under the trade name Astelin or Astepro.  It is used for and quite effective for the relief of perennial and seasonal allergic rhinitis (i.e., hay fever) symptoms such as sneezing, runny nose, nasal congestion, post-nasal drip, itchy nose, itchy throat, sinus congestion, sinus headaches, itchy eyes, puffy eyes, watery eyes, and/or redness of the eyes.  Azelastine also has previously demonstrated anti-viral activity against respiratory viruses such as influenza (i.e., flu), respiratory syncytial virus (RSV), and some coronaviruses, in addition to its anti-allergic and anti-inflammatory properties. Clinical trials have demonstrated that azelastine nasal spray reduces viral load in patients with confirmed SARS-CoV-2 infection, suggesting therapeutic efficacy in the acute treatment of COVID-19.  These findings prompted researchers to study whether azelastine can also be used as a prophylaxis to prevent Covid-19 infection. In a clinical trial published in the Journal of American Medical Association-Internal Medicine this month (September 2025), a team of investigators attempted to shed further light on this topic.  They recruited 450 healthy volunteers who were 18 to 65 years of age with no signs of an acute infection for the study.  Participants were randomly assigned 1:1 to receive azelastine 0.1% nasal spray or placebo 3 times a day for 56 days.  SARS-CoV-2 rapid antigen testing (RAT) was conducted twice a week with positive results confirmed by polymerase chain reaction (PCR). The primary end point was the number of polymerase chain reaction-confirmed SARS-CoV-2 infections during the study.  The results of the trial revealed that the incidence of PCR-confirmed SARS-CoV-2 infection was significantly lower in the azelastine group compared with the placebo group.  As secondary end points, azelastine demonstrated an increase in mean time to SARS-CoV-2 infection among infected individuals, a reduction of the overall number of PCR-confirmed symptomatic infections, and a lower incidence of PCR-confirmed rhinovirus infections.  Note that rhinovirus is the most common cause of the common cold. Adverse events were comparable between the groups, except for a bitter taste which was experienced by more individuals in the azelastine group compared to placebo.  Azelastine nasal spray has long been known to cause a bitter taste in one’s mouth in patients using the nasal spray for the treatment of allergic rhinitis. The nasal mucus membrane, as the primary site of viral entry and replication, plays a critical role in the pathogenesis of respiratory viral infections.  The ability of locally applied and locally acting azelastine nasal spray to significantly reduce SARS-CoV-2 and overall upper respiratory tract infections underscores the efficacy of topical nasal interventions. The findings of this randomized clinical trial suggest that azelastine nasal spray may reduce the incidence of respiratory infections caused by SARS-CoV-2.  Although not studied yet, maybe other nasal antihistamines such as olopatadine (i.e., Patanase) may also reduce or prevent the incidence of respiratory infections caused by SARS-CoV-2. The board certified allergy specialists at Black & Kletz Allergy have 3 convenient locations with on-site parking located in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  The Washington, DC and McLean, VA offices are Metro accessible and we offer a free shuttle that runs between the McLean, VA office and the Spring Hill metro station on the silver line.  The allergy doctors at Black & Kletz Allergy are extremely knowledgeable regarding allergic rhinitis (i.e., hay fever) as well as non-allergic rhinitis.  We are very experienced using azelastine for the treatment of allergic rhinitis.  We diagnose and treat both adult and pediatric patients.  In addition, we treat patients with food, insect sting, medication, and skin allergies, as well as asthma, sinus disease, eosinophilic esophagitis, and immunological disorders.  To schedule an appointment, please call any of our offices or you may alternatively click Request an Appointment and we will respond within 24 hours by the next business day.  We have been servicing the Washington, DC, Northern Virginia, and Maryland metropolitan area for more than 5 decades and we look forward to providing you with comprehensive state-of the-art allergy care in a welcoming and professional environment.
Autumn Allergies

September 26, 2025 | Black & Kletz Allergy

Autumn AllergiesAutumn has just begun and for some people it is a bittersweet moment.  Although many individuals enjoy the lower temperatures that the autumn brings in the Washington, DC, Northern Virginia, and Maryland metropolitan region, many allergy sufferers are not so welcoming because with the lower temperatures, mold and weed pollen levels rise.  The major weed culprit in the DC area is ragweed, although many other weed pollens increase during the Fall such as pigweed, sorrel, dock, milkweed, and lamb’s quarters.  In the U.S., ragweed allergy is common as approximately 10% of the population suffers from ragweed pollen.  Approximately 50% of all pollen-associated allergic rhinitis (i.e., hay fever) in North America is due to ragweed, particularly in the Eastern and Midwestern regions.  Ragweed also causes allergic conjunctivitis (i.e., eye allergies) and asthma in other sensitive individuals. There are 17 species of ragweed in North America.  The only state in the U.S. without ragweed is Alaska.  Each ragweed plant produces approximately 1 billion pollen grains. The ragweed plant lives only 1 season.  Although ragweed is almost ubiquitous in the U.S., the pollen is even more widespread in rural areas.  Ragweed is typically found along the side of the road, in vacant lots, in fields, and along riverbanks.  Environmental factors play a role in the release of ragweed pollen.  The warm weather in combination with the wind and increased humidity augments the release of ragweed pollen which in the mid-Atlantic region tends to begin in mid-August, peak in mid-September, and end with the first frost which typically occurs in late October.  The ragweed pollen count tends to be its highest during the midday and lowest in the early mornings.  The pollen released from the ragweed plant can travel hundreds of miles, like other pollens, so most of the U.S. population is exposed. Most weed-sensitive individuals complain of the typical allergy symptoms associated with allergic rhinitis or allergic conjunctivitis.  The symptoms may include sneezing, runny nose, nasal congestion, post-nasal drip, sinus congestion and pressure, sinus headaches, fatigue, itchy nose, itchy throat, snoring, itchy eyes, watery eyes, puffy eyes, and/or redness of the eyes.  Individuals with asthma may also have an exacerbation of their asthma with symptoms such as wheezing, coughing, chest tightness, and/or shortness of breath.  Patients prone to sinus infections (i.e., sinusitis) may develop a sinus infection during the autumn as a result of the high weed pollen count. In addition to weeds, there are other environmental allergens that may be responsible for an uptick in allergy symptoms to allergic individuals in the autumn.  Besides ragweed and other weeds, molds, dust mites, pets, and cockroaches are common allergens that may play a role in inducing allergic rhinitis, allergic conjunctivitis, and/or asthma symptoms in susceptible individuals.  In fact, all of these allergens are perennial and may be bothersome to sensitive individuals throughout the year, not only in the autumn.  In particular, leaf mold is quite annoying to many allergy sufferers, particularly to people who like to garden and rake leaves.  It should be noted that dust mites, pets, and cockroaches are indoor allergens whereas weeds are outdoor allergens.  Molds, however, are both indoor and outdoor allergens and are particularly bad in the Washington, DC metro area because DC was built on a swamp and there is high humidity in this region. It is also interesting to note that there are certain foods that are closely associated with ragweed such that when eaten by ragweed-sensitive individuals, they may experience an itchy mouth, throat, and/or lips.  People with this condition are said to have oral allergy syndrome or pollen-food allergy syndrome.  It occurs in response to eating certain raw or uncooked fruits, vegetables, and/or nuts by the ragweed-sensitive person.  Occasionally, one may experience itching of the hands when touching raw foods.  Some examples of foods associated with ragweed pollen allergy include banana, melon (e.g., honeydew, cantaloupe, watermelon), chamomile tea, cucumber, zucchini, white potato, dandelion, sunflower seeds, and artichoke.  Although ragweed-sensitive patients may develop an itchy mouth, throat, and/or lips when they eat these foods raw or fresh, when the fruit or vegetable is cooked or canned, the protein is denatured and thus destroyed which usually prevents the allergic reaction from occurring.  In most cases, individuals are able to tolerate cooked and/or canned fruits and vegetables.  Of note, oral allergy syndrome may also occur in individuals who have other pollen allergies such as tree pollen.  A classic example of this is that some individuals who have birch tree allergies will have itching of the mouth, throat, and/or lips when eating raw or fresh pitted fruits (e.g., apples, peaches, plums, pears).  Extra caution needs to be taken in cases where nuts cause symptoms because many individuals can have a classic nut allergy that is not associated with pollen which may be life-threatening.  Such individuals should be prescribed a self-administered epinephrine device such as an EpiPen, Auvi-Q, Adrenaclick, or Neffy, an epinephrine containing nasal spray.  Patients should be instructed that if they use the self-administered epinephrine device, they should go immediately to the closest emergency room. The board certified allergists at Black & Kletz Allergy has 3 convenient locations in the Washington, DC metro area.  We have offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA which all offer on-site parking.  The Washington, DC and McLean, VA locations are Metro accessible and there is a free shuttle that runs between the McLean, VA office and the Spring Hill metro station on the silver line.  Please call us to make an appointment or you can click Request an Appointment and we will reply within 24 hours by the next business day.  The allergy specialists of Black & Kletz Allergy are eager to help you with your autumn allergies (i.e., hay fever), asthma, hives, swelling episodes, mast cell condition, eosinophilic esophagitis, sinus issues, or any other allergy and immunology problems.  We are dedicated to providing first-rate care to you as we have been doing in the Washington, DC metro area for more than 50 years.
Alpha-Gal Syndrome Update

August 18, 2025 | Black & Kletz Allergy

Alpha-Gal Syndrome Alpha-Gal SyndromeOver the last 10-15 years, the number of individuals with meat allergy has risen mainly because of a condition called alpha-gal syndrome or mammalian meat allergy.  Alpha-gal syndrome was first identified by Dr. Thomas Platts-Mills at the University of Virginia School of Medicine in 2002.  He discovered that the syndrome originated from the bite of lone star ticks (Amblyomma americanum).  Specifically, the IgE antibody (i.e., the allergy antibody) response to the mammalian sugar molecule known as alpha-gal was associated with a delayed-onset swelling (i.e., angioedema) and/or anaphylaxis 2 to 8 hours after eating mammalian food products, such as beef, lamb, pork, and/or venison. Alpha-gal, officially referred to as galactose-alpha-1,3-galactose, is a carbohydrate (i.e., sugar molecule) that exists in most mammals (e.g., pigs, cows, deer, sheep, rabbits, whales).  It is not found however in humans or non-mammals such as birds, reptiles or fish.  Lone star ticks can transfer this alpha-gal carbohydrate molecule to humans by first biting and feeding on mammals and then biting humans.  After someone is bitten by a lone star tick, the alpha-gal molecule, which is present in the tick’s saliva, is transmitted into the individual’s bloodstream.  In turn, that person will produce IgE antibodies as a defense mechanism against this foreign carbohydrate molecule (i.e., sugar molecule).  As a result, that person now has alpha-gal IgE antibodies present in their bloodstream.  Going forward, after the sensitization to alpha-gal occurs, whenever that individual eats mammalian meat which naturally contains the sugar molecule galactose alpha-1,3-galactose (i.e., alpha-gal), their alpha-gal IgE antibodies will bind and react against the alpha-gal present in the mammalian meat (e.g., pork, beef, venison, lamb, rabbit, whale) and cause the person to exhibit allergic symptoms.  The typical and more common symptoms experienced by someone with alpha-gal syndrome include hives (i.e., urticaria)swelling (i.e., angioedema) and/or anaphylaxis in more severe cases. There is also a newer variant of alpha-gal syndrome referred to as gastrointestinal (GI) alpha-gal.  Gastrointestinal alpha-gal presents with GI symptoms such as nausea, vomiting, diarrhea and/or abdominal pain without the predominant skin, respiratory, or circulatory symptoms.  It should be noted that there are IgE antibodies present on human mast cells that richly populate the gastrointestinal tract.  In patients with the variant called gastrointestinal (GI) alpha-gal, as a result of the binding of the alpha-gal molecule with the IgE antibodies on the mast cells in the gastrointestinal tract, degranulation of the mast cells occur which causes the release of large amounts of histamine and other inflammatory chemical mediators into the bloodstream.  These chemical mediators can in turn act on sensory nerve endings to cause the intestinal smooth muscles to cause contractions which produce pain as well as the mucous glands in the GI tract to produce more mucous.  Note that these vague abdominal symptoms can be and often are confused with other gastrointestinal conditions such as irritable bowel syndrome (IBS) or classic food allergies.  One way to differentiate between a common food allergy and alpha-gal syndrome is that onset of symptoms is typically several hours after the ingestion of the mammalian meat in patients who have alpha-gal syndrome.  A history of waking up at night from sleep with gastrointestinal distress may suggest that the person has alpha-gal syndrome given the delay in symptoms that occurs in this condition.  In individuals with classic food allergies, the abdominal symptoms usually occur fairly quickly after ingesting the offending food. Diagnosis: The diagnosis of alpha-gal syndrome begins by performing a comprehensive history and physical examination.  The diagnosis is helped if there has been a recent tick bite, although it is not crucial to make the diagnosis as not all patients remember if they have had a recent tick bite.  A blood test for alpha-gal antibody should be taken and laboratory findings are positive for the alpha-gal antibody in individuals with the condition.  The diagnosis is often not made due to the fact that there is usually a time period between the tick bite and the advent of symptoms.  Thus, the diagnosis is typically underdiagnosed.  Note that the gold standard to diagnose regular IgE-mediated food allergies is the oral food challenge, but in the case of alpha-gal syndrome, the oral food challenge is unreliable since there is typically a delay in symptoms for several hours after the ingestion of mammalian meat. Treatment: Eliminating the consumption of all mammalian meat (e.g., beef, pork, venison, lamb, rabbit, whale) and mammalian products (e.g., milk, butter, lard) is the only way to manage this condition.  Dairy products do contain smaller amounts of alpha-gal, particularly cream cheese, cream, and ice cream, cream, which have a high fat content.  Gelatin is derived from the collagen in pig or cow bones.  As a result, foods that contain gelatin (e.g., gelatin candies, gummy bears, marshmallows) may likewise trigger allergic reactions.  Processed foods can also have small amounts of animal-derived products.  Restaurants may cross-contaminate foods with alpha-gal which may be a problem for individuals with high levels of sensitivity to alpha-gal. Prevention: The treatment of alpha-gal syndrome is simply prevention.  Patients with alpha-gal syndrome should take actions to avoid further tick bites because additional lone star tick bites may worsen the allergy.  Checking regularly for ticks, showering soon after outdoor activities in grassy and woody areas, treating clothes and shoes with permethrin, and creating a barrier at the ankles by pulling up one’s socks over the pant cuffs when outside may all help reduce the likelihood of tick bites. Certain medications such as cetuximab (i.e., Erbitux) and pancreatic enzymes are derived from pigs and may cause problems in individuals with alpha-gal syndrome.  A company in Blacksburg, VA has developed alpha-gal-free pork, which is FDA-approved but not yet widely available.  Another option for alpha-gal allergic individuals is to consume plant-based substitutes to meat commonly found in companies such as Beyond Meat or Impossible Burger. All patients diagnosed with alpha-gal allergy should carry a self-injectable epinephrine device (e.g., EpiPen, Auvi-Q, Adrenaclick) or an epinephrine nasal spray (e.g., Neffy) for use in case of a systemic reaction following an unintended exposure to mammalian meat.  If a self-injectable epinephrine device or an epinephrine nasal spray is used, the patient should go immediately to the closest emergency room. The board certified allergy doctors at Black & Kletz Allergy have been diagnosing and treating allergies, asthma, sinus conditions, and immunological disorders for more than 5 decades.  Black & Kletz Allergy has 3 convenient locations in the Washington, DC metro area with offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  We offer on-site parking at each location and the Washington, DC and McLean offices are Metro accessible.  There is a free shuttle that runs between our McLean, VA office and the Spring Hill metro station on the silver line.  Please call us today to make an appointment at the office of your choice.  Alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day.  The allergists at Black & Kletz Allergy pride themselves in delivering the highest quality allergy care in the Washington, DC metropolitan area in conjunction with providing excellent customer service in a welcoming and pleasant environment.
Toxic Epidermal Necrolysis

August 13, 2025 | Black & Kletz Allergy

Toxic Epidermal Necrolysis Toxic epidermal necrolysis (TEN) is a painful, life-threatening skin condition.  It is associated with blistering and peeling of large areas of the skin, including mucous membranes such as the mouth, eyes, and/or genitals. If less than 10% of the body surface is involved, it is often called Stevens- Johnson syndrome (SJS).  In the more severe form, which is referred to as toxic epidermal necrolysis, usually more than 30% of the body surface area is affected.  These 2 conditions overlap when between 10 and 30% of body surface is involved. The most common cause of toxic epidermal necrolysis is an adverse reaction to medications.  The most common medications implicated in the causation are antibiotics and anti-seizure medications. Fortunately, toxic epidermal necrolysis/Stevens-Johnson syndrome is a very rare complication of medication use where it is estimated that there are 0.4 - 1.2 cases per million each year for toxic epidermal necrolysis and 1 - 2 cases per million each year for Stevens-Johnson syndrome.  Certain genetic factors may predispose one to this condition.  It can affect all age groups and is slightly more common in females than in males.  Toxic epidermal necrolysis is 100 times more common in association with human immunodeficiency virus infection (HIV). The most common medications causing toxic epidermal necrolysis are:
  • Sulfonamides:  Bactrim (i.e., sulfamethoxazole + trimethoprim)
  • Beta-lactam Antibiotics:  penicillins, cephalosporins
  • Anticonvulsants:  Lamictal (i.e., lamotrigine), Tegretol (i.e., carbamazepine, Dilantin (i.e., phenytoin), phenobarbital
  • Allopurinol - A medication to lower high uric acid levels)
  • Tylenol (i.e., acetaminophen or paracetamol)
  • Viramune (i.e., nevirapine) - An anti-HIV medication
  • Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)
  • Anti-cancer Medications
Toxic epidermal necrolysis/Stevens-Johnson syndrome has rarely been associated with vaccination or mycoplasma and cytomegalovirus infections.  Infections are generally associated with mucosal involvement and less severe cutaneous disease than when drugs are the cause. Symptoms: Toxic epidermal necrolysis usually develops within the first week of antibiotic therapy but typically develops up to 2 months after beginning an anticonvulsant.  Before the rash appears, there is usually a prodromal illness of several days duration resembling an upper respiratory tract infection or flu-like illness.  The symptoms for this prodromal illness may include a mild fever, sore throat, achiness, watery eyes, red eyes, nasal congestion, runny nose, cough, and/or generalized fatigue. This prodromal stage is followed by a tender or painful red skin rash, beginning on the trunk and extending rapidly over hours to days onto the face and limbs, but rarely affecting the scalp, palms, or soles).  Initially, reddish areas and small blisters may develop.  The blisters then merge to form sheets of skin detachment causing redness and oozing from deeper layers of the skin.  Erosions, or painful open wounds that look like burns, develop as the skin peels away. Mucosal involvement is prominent and severe, although no actual blisters are formed.  At least 2 mucosal surfaces are affected including:
  • Eyes - red, soreness, stickiness, photosensitivity
  • Lips/Mouth - red crusty lips, painful mouth ulcers
  • Pharynx/Esophagus - difficulty eating
  • Genital Area and Urinary Tract - erosions, ulcers
  • Upper Respiratory Tract - cough, respiratory distress
  • Gastrointestinal Tract - diarrhea
Complications: Toxic epidermal necrolysis/Stevens-Johnson syndrome can be fatal due to complications in the acute phase.  The mortality rate is up to 10% for Stevens-Johnson syndrome and at least 30% for toxic epidermal necrolysis. During the acute phase, potentially fatal complications may include:
  • Dehydration and/or acute malnutrition
  • Infection of the skin, mucous membranes, lungs (i.e., pneumonia), septicemia (i.e., blood poisoning) with bacteria or fungus
  • Acute respiratory distress syndrome
  • Gastrointestinal ulceration and/or perforation
  • Shock and multiple organ failure
  • Excessive blood clotting and/or bleeding
Diagnosis: A skin biopsy is usually required to confirm the clinical diagnosis.  Blood tests do not help make the diagnosis but are essential to monitor if fluid and vital nutrients have been replaced, as well as to identify complications. Bloodwork can identify anemia, low WBC’s and platelets, elevated liver enzymes and/or protein loss in the urine which are not uncommon in this condition. Treatment:
  • Immediate discontinuation of the suspected triggering drug
  • Nutritional and fluid replacement
  • Temperature maintenance
  • Pain relief
  • Sterile handling and reverse isolation
  • Systemic antibiotics at the first sign of an infection
  • Topical antiseptics such as silver nitrate and chlorhexidine
  • Dressings such as gauze with petrolatum (i.e., petroleum jelly)
  • Frequent eye drops/ointments (e.g., antiseptics, antibiotic, corticosteroids)
  • Mouthwashes and oral anesthetics
  • Corticosteroids and immunosuppressant medications
  • Immune globulin supplementation
The board certified allergy specialists at Black & Kletz Allergy have 3 locations in the Washington, Northern Virginia, and Maryland metropolitan area.  Our offices are located in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  All of our offices have on-site parking and the Washington, DC and McLean, VA offices are also Metro accessible.  The McLean office has a complementary shuttle that runs between our office and the Spring Hill metro station on the silver line.  The allergists at Black & Kletz Allergy diagnose and treat both pediatric and adult patients.  To make an appointment, please call our office or you may click Request an Appointment and we will respond within 24 hours by the next business day.  The allergy doctors at Black & Kletz Allergy have been helping patients with allergic skin disorders, as well as and other allergic conditions such as hives, eczema, hay fever, asthma, sinus disease, food allergies, medication allergies, insect sting allergies, and immunological disorders for more than 50 years.  If you suffer from an allergic skin condition or any other type of allergy, it is our mission to improve your quality of life by decreasing or preventing your unwanted and annoying allergy symptoms.
Update on Pet Allergies

July 18, 2025 | Black & Kletz Allergy

Update on Pet AllergiesPet allergies are quite common in the United States.  About 20% of the U.S. population have cat allergies and 10% of the people in the U.S. have dog allergies.  Approximately 70% of the homes in the U.S. have at least 1 pet with dogs being the most common pet, followed by cats.  The percentage of homes with pets is higher than in the past as more and more families are getting pets.  The Labrador Retriever is the most common pet dog and the Ragdoll is the most common pet cat.  There are roughly 77 million pet dogs living in the U.S, however there are only 49 million households with dogs.  In other words, each dog-owning home has an average of 1.5 dogs.  In contrast, there are roughly 59 million cats living in approximately 32 million homes, which is equivalent to 1.8 cats per household. When someone says that they are allergic to a pet, they are really saying that they are allergic to one or more of the proteins that are produced in the sebaceous glands of the skin (dander), saliva, and/or urine of that animal.  In dogs, the major protein responsible for their allergies is called “Can f 1.” Note that the “Can” in “Can f 1” is short for canine or dog.  This protein is produced by dogs and commonly found in the dog’s dander, saliva, and urine.  In cats, similarly, the major proteins associated with their allergies are called “Fel d 1” and “Fel d 4.”  Note that the “Fel” in both of the proteins “Fel d 1” and “Fel d 4” is short for feline or cat. Besides the fact that there are different proteins responsible for allergies to cats and dogs, there is also a difference in the dander between these 2 pets.  Cat dander is “sticky” whereas dog dander is not.  Cat dander tends to stick to walls, clothing, upholstered furniture, bedding, and carpeting.  It is commonly transported from one’s house to other houses or to workplaces.  An example of this phenomenon is illustrated by the fact that if the Fel d 1 protein is measured on a cat owner’s clothing or upholstered furniture at work, it is likely that the protein will be found.  In addition, it usually take several months for these “allergic” proteins to dissipate and become undetectable, despite a thorough cleaning of the home, due the stick-to-itiveness of cat dander.  Although cat dander is stickier than dog dander, it does not mean that dog dander cannot stick to walls, clothing, upholstered furniture, bedding, and carpeting.  It just means that the proteins associated with cat dander will linger more in one’s home more than dog dander.  It should also be noted that since the proteins associated with cats are also found in urine, cat litter boxes are a rich source of these proteins and cat-allergic individuals should avoid exposure to litter boxes, if at all possible. Interestingly, there is a condition called pork-cat syndrome that may affect individuals who are allergic to cats.  In this syndrome, cat-allergic individuals develop an allergy to consuming pork.  The severity can be severe and even life-threatening.  Pork-cat syndrome affects females much more than male individuals since approximately 80% of the people with this condition are females.  Avoiding the consumption of pork is crucial in these individuals and patients with this syndrome should carry a self-injectable epinephrine device (e.g., EpiPen, Auvi-Q, Adrenaclick) or an epinephrine nasal spray (e.g., Neffy).  If they use the epinephrine containing device, they should go immediately to the closest emergency room. Another interesting fact is that there is an increased incidence of horse allergy in some individuals that have cat and/or dog allergies due to a common protein that is shared between all 3 animals.  The dander is the most common way in which horses cause allergic symptoms in humans.  The horse’s saliva, urine, and the fecal material dropped by horse mites are other ways that individuals are exposed to the allergenic proteins of horses.  There are roughly 4 million households in the U.S. that own horses.  Obviously, horses do not normally live in people’s homes, but they still cause allergic symptoms in many individuals.  Recently, it has become fashionable to own miniature horses, which in some cases, do live in the homes of their owners.  Living in a house with a horse in general is probably not the best idea, but for individuals with horse allergies, it is especially not a good idea. In rodents, unlike cats and dogs, in addition to the allergenic protein being present in the urine, dander, and saliva, certain rodents such as mice contain allergenic proteins in their mouse fecal droppings.  In birds, the protein responsible for their allergies is also present on their feathers, as well as urine, dander, saliva, and fecal droppings. The symptoms of pet allergies are essentially the same as with any other environmental allergy (i.e., hay fever or allergic rhinitis) such as dust mites, pollens, and/or molds.  The main difference is that sometimes when a pet licks or scratches someone, the pet-allergic individual may get an itchy rash where they are licked or scratched.  Otherwise, the most common symptoms when a pet-allergic individual is in close proximity to a pet may include sneezing, runny nose, nasal congestion, sinus congestion, post-nasal drip, generalized itching, hives, itchy eyes, watery eyes, puffy eyes, and/or redness of the eyes.  In patients with asthma, chest tightness, wheezing, coughing, and/or shortness of breath may occur. The diagnosis of pet allergies begins with a comprehensive history and physical examination.  Allergy testing by skin testing or occasionally blood testing is the standard procedure to further identify if someone is allergic to pets. The treatment of pet allergies begins with avoidance.  This is not always easy and most people have a close bond with their pets, which is understandable.  Nevertheless, if the pet cannot be avoided, simple measures to decrease exposure to them may help remedy the situation such as keeping the pet out of the bedroom or washing the pet fairly frequently.  Medications such as antihistamines, decongestants, corticosteroid nasal sprays, antihistamine nasal sprays, anticholinergic nasal sprays, leukotriene antagonists, and/or allergy eye drops may be beneficial in helping to relieve the annoying allergy symptoms.  When all of the above have been taken into consideration, allergy immunotherapy (i.e., allergy shots, allergy injections, allergy desensitization, allergy hyposensitization) is a very effective treatment to alleviate and prevent pet allergy symptoms. Black & Kletz Allergy has board certified allergy doctors in 3 convenient locations in the greater Washington, DC, Northern Virginia, and Maryland metro area.  Our allergy specialists very familiar with your furry friends and can help you with your pet allergies.  The allergists at Black & Kletz Allergy diagnose and treat both children and adults.  We offer on-site parking in our Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA locations.  The Washington, DC and McLean, VA offices are Metro accessible and the McLean office has a free shuttle that runs between the McLean office and the Spring Hill metro station on the silver line.  If you are concerned that you or your child has a pet allergy or any other type of allergy or asthma, please call us to schedule an appointment.  Alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day.  Black & Kletz Allergy has been serving the needs of allergy and asthma sufferers in the Washington, DC metropolitan area for more than 50 years.
Erythema Multiforme

July 8, 2025 | Black & Kletz Allergy

Erythema MultiformeErythema Multiforme is a type of a rash on the skin, usually triggered by an infection or an adverse effect of a medication.  The condition gets its name from the appearance of reddish skin lesions of various forms seen at the same time. Erythema multiforme affects less than 1% of the population.  It is most common in young adults (aged 20 - 40 years) with a modest predominance in males.  Some people are genetically predisposed to develop erythema multiforme. Causes:
Erythema multiforme is an immunological response to either an infection or a medication, manifested on the skin.  The most common causative factors are:
  • Infections - Herpes simplex virus (most common), mycoplasma, cytomegalovirus, Epstein-Barr virus, influenza virus, coronavirus, etc.
  • Medications - Antibiotics (e.g., sulfonamides, tetracyclines, erythromycin), aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs) (e.g., ibuprofen, naproxen), anti-seizure medications, and vaccines.
  • Systemic disorders - Inflammatory bowel disease, hepatitis, lymphoma, leukemia, and solid organ tumors.
Diagnosis:
  • After exposure to the trigger, there is usually a prodromal period when the individual may experience mild fever, cold like symptoms, sore throat, headache, fatigue, and/or achiness.
  • A few days later, the typical skin lesions will erupt.  These lesions may be in the form of red papules (i.e., small raised bumps), vesicles (i.e., blisters filled with clear fluid), ulcers (i.e., skin sores), etc.
  • Characteristic lesions are ‘bulls-eye’ target lesions with a central dusky area, surrounded by a pale edematous area and a peripheral reddish ring, demarcating it from the surrounding normal skin.
  • Atypical lesions are raised with poorly defined borders and/or fewer zones of color variation.
  • Several lesions in different developmental stages may be seen at the same time.
  • The skin lesions are usually symmetrical, begin at the periphery and spread centrally.  The skin lesions usually have a predilection to extensor surfaces (i.e., outer side of the limbs)
  • Skin lesions may be very itchy, painful, and/or swollen.
  • Confirmation of the diagnosis may require a skin biopsy.
  • Tests for infections, especially herpes simplex virus, are needed.
Types:
There are 2 types of erythema multiforme:
  1. Erythema multiforme minor - Mild form of the illness that only affects the skin and causes a rash.
  2. Erythema multiforme major - Most severe form of the condition which may be life-threatening because it causes large areas of the skin to blister and peel.  This type affects the mucus membranes in the mouth, eyes, and genitals.  Individuals usually have systemic symptoms such as fevers and/or joint pain.
Erythema multiforme is not contagious.  The lesions, blisters, or rash on the skin cannot spread from person to person.  The viruses and other agents that caused the infection, however, can spread from one person to another. Treatment:
  • Most cases of erythema multiforme are mild and self-limiting and usually resolve spontaneously after a few days or weeks.
  • Antihistamines and topical corticosteroid medications are helpful in relieving the itching and discomfort associated with more severe skin lesions.
  • Antiseptic and local anesthetic mouthwashes may help relieve the pain and irritation associated with mucus membrane lesions inside the mouth.
  • Antihistamine or anti-inflammatory eye drops can treat redness, burning, and/or excessive tearing of the eyes.
  • Proper care of skin lesions such as avoidance of scratching will help prevent the spread of infections.
  • Most severe cases may need a course of systemic corticosteroids such as oral prednisone.
  • Recurrent cases are usually treated with 6 months or more of continuous oral antiviral medications such as acyclovir.
Prevention:
  • General hand and respiratory hygiene is important in order to reduce the risk of contracting viral and bacterial infections.
  • Avoiding medications that had previously caused adverse reactions in the past.
The board certified allergy specialists at Black & Kletz Allergy have 3 locations in the Washington, Northern Virginia, and Maryland metropolitan area.  Our offices are located in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  All of our offices have on-site parking and the Washington, DC and McLean, VA offices are also Metro accessible.  The McLean office has a complementary shuttle that runs between our office and the Spring Hill metro station on the silver line.  The allergists at Black & Kletz Allergy diagnose and treat both pediatric and adult patients.  To make an appointment, please call our office or you may click Request an Appointment and we will respond within 24 hours by the next business day.  The allergy doctors at Black & Kletz Allergy have been helping patients with allergic skin rashes, hives (i.e., urticaria), eczema (i.e., atopic dermatitis), as well as other causes of allergies including hay fever (i.e., allergic rhinitis), asthma, sinus disease, food allergies, medication allergies, insect sting allergies, and immunological disorders for more than 50 years.  If you suffer from an allergic skin rash or any other type of allergies it is our mission to improve your quality of life by minimizing or preventing your unwanted and annoying allergy symptoms.
Prurigo Nodularis

June 27, 2025 | Black & Kletz Allergy

Prurigo NodularisPrurigo nodularis is a chronic inflammatory skin disease where an extremely itchy rash in the form of firm bumps called nodules appears most commonly on the arms, legs, upper back, and/or abdomen.  The rash is usually symmetrically distributed on both sides of the body.  The itchiness, burning, and stinging sensation associated with prurigo nodularis is so severe that it often interferes with sleep and one’s psychological well-being. The exact cause of prurigo nodularis is unknown, but altered function of the immune system and nerves in the skin is believed to be associated with heightened sensations of itchiness (i.e., pruritus) that leads to frequent scratching.  Frequent scratching and picking of the skin are also thought to contribute to further lesion formation and thickening seen in the disease. Prurigo nodularis can occur at any age but is more common in the elderly. When it occurs in younger patients, it is more likely to be associated with inflammatory skin diseases, usually eczema (i.e., atopic dermatitis).  Prurogo nodularis is also more likely to manifest in patients with other underlying medical conditions that affect multiple body systems, such as cancer, diabetes, chronic kidney disease, and HIV infection.  Prurigo nodularis is not hereditary or contagious. The rash and itching can be episodic or continuous, lasting for several months in some individuals.  It is typically worsened by sweat, heat, synthetic clothing, and/or stress.  The rash can range in severity from just a few to several hundred lesions.  The lesions can range in size from 0.2 inches to 0.8 inches wide and can appear as firm, dome-shaped papules, nodules, or plaques.  Lesions can be flesh-colored, pink, red, brown, or black in color. Diagnosis:
  • The characteristic appearance and distribution of the lesions, the chronicity, and association with other systemic disorders provide clues to the diagnosis of prurigo nodularis.
  • The confirmation of the diagnosis is established by biopsy of the skin lesions and examination of them under a microscope.  It usually reveals thickening of different areas of the outermost layer of the skin (i.e., epidermis) with distinct changes (i.e., hyperkeratosis) to the skin protein keratin.  The layer below the epidermis, referred to as the dermis, shows an increase in several inflammatory white blood cell types.
  • Blood tests including a complete blood cell count (CBC), a comprehensive metabolic panel (CMP) that includes liver and kidney function tests, and a thyroid hormone panel may be beneficial for diagnosing an underlying systemic disease that may be contributing to the prurigo nodularis.
Treatment:
  • Behavioral treatments for prurigo nodularis include ways to prevent scratching and dryness, such as keeping fingernails short, wearing long sleeves, wearing gloves, bandaging lesions, cleaning skin with gentle cleansers, keeping skin moisturized with non-irritating lotions, and avoiding warm environments to reduce sweating. Recommended anti-itch lotions include calamine, menthol, and camphor lotions.
  • Moisturizers such as petroleum jelly, fragrance-free and ceramide-rich creams or ointments, and fragrance-free oatmeal or hyaluronic acid creams.
  • Second generation oral antihistamines such as Zyrtec, Xyzal, Allegra, Claritin, or Clarinex taken on a regular basis.  Many patients need 2 to 3 times the regular daily dose to get adequate relief from the severe itching and/or burning sensation that can be present in some individuals.
  • Some patients respond better to first generation sedating antihistamines such as Palgic, Periactin, Atarax, or Benadryl.
  • Topical medications such as corticosteroids (e.g., triamcinolone, fluocinonide, betamethasone, mometasone, clobetasol, fluticasone, desoxymetasone), calcineurin inhibitors (e.g., pimecrolimus, tacrolimus), capsaicin (the spicy ingredient in chili peppers), and vitamin D.
  • Phototherapy:  Exposing affected areas of the skin to specific wavelengths of ultraviolet (UV) light may help reduce the itchiness and inflammation of the skin.
  • In 2022, dupilumab (i.e., Dupixent), an interleukin-4 receptor alpha antagonist, was approved by the U.S. Food and Drug Administration (FDA) to treat adults with prurigo nodularis.  It is a subcutaneous (SQ) injection which can be self-administered under the skin every 2 weeks.
  • In 2024, nemolizumab (i.e., Nemluvio), an interleukin-31 receptor antagonist, was approved by the FDA to treat adults with prurigo nodularis.  It is a subcutaneous (SQ) injection administered every 4 weeks.
  • Immunosuppressants such as cyclosporin, azathioprine, and methotrexate are reserved for the most resistant cases of prurigo nodularis because they affect more body systems and can have more serious side effects.
The board certified allergy specialists at Black & Kletz Allergy will promptly answer any questions you may have regarding prurigo nodularis or any other itching disorder.  Our allergists have been diagnosing prurigo nodularis and other skin conditions in the Washington, DC, Northern Virginia, and Maryland metropolitan area for more than 50 years.  We have 3 convenient locations in the DC metro area with offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  There is on-site parking at each location and both the Washington, DC and McLean, VA offices are Metro accessible.  There is a free shuttle that runs between our McLean, VA office and the Spring Hill metro station on the silver line.  To schedule an appointment, please call us at any one of our 3 locations.  Alternatively, you can click Request an Appointment and we will respond within 24 hours by the next business day.  Black & Kletz Allergy is dedicated in providing the most up-to-date diagnostic and treatment modalities in the field of allergy, asthma, and immunology.
Summer Outdoor Allergies

June 16, 2025 | Black & Kletz Allergy

Now that Summer is almost here, people tend to spend a lot of time outdoors. Whether it be going to the beach, swimming at the neighborhood pool, playing baseball or softball, having a picnic, fishing, hiking, riding bicycles, gardening, or any other outside activity, people are more likely to be outdoors now than in any other season of the year. Since the general public is outdoors more in the Summers, it should be noted that there are a lot of outdoor allergens that they are being exposed to when outside. The most obvious allergens that come to mind are the pollens, which are associated with late Spring and Summer. In the Washington, DC, Northern Virginia, and Maryland metropolitan area, tree, grass, and ragweed pollens make up the bulk of the pollens that tend to cause allergy symptoms in susceptible individuals. Tree pollen generally is released at the end of February and it lasts until late May or early June. Grass pollen, on the other hand, usually begins to pollinate in late April or early May and lasts until the end of August. Ragweed, a type of weed that is quite bothersome to some individuals, generally begins to pollinate in mid-August and ends after the first frost which is usually in late October. The classic symptoms associated with pollen allergies typically include one or more of the following symptoms: sneezing, runny nose, nasal congestion, post-nasal drip, itchy nose, itchy mouth, itchy eyes, watery eyes, redness of the eyes, snoring, headaches, and/or sinus congestion. In those individuals with asthma whose asthma is exacerbated by pollen, chest tightness, wheezing, coughing, and/or shortness of breath may also ensue. In addition to pollens as a source for summertime allergies, one must be cautious of flying insects, particularly if that person has a history of hives or a systemic allergic reaction resulting from an insect sting. In the Washington, DC metro area, bees, wasps, yellow jackets, white-faced hornets, and yellow-faced hornets are the major flying insects that inject venom into humans. Some individuals will naturally develop an immune response to further stings with that species of insect. As a result, when that person is subsequently stung with the insect that they are allergic to, an allergic reaction occurs which may be mild, moderate, or severe. Severe allergic reactions to flying insects due to venom allergy may be life-threatening. Anyone who has a history of hives and/or a systemic reaction to a flying insect, whether it be mild, moderate, or severe, should seek a board certified allergist to get evaluated. Allergy blood testing or allergy skin testing is warranted and depending on the results of the tests, a course of venom immunotherapy (i.e., allergy shots to venomous flying insects such as bees, wasps, yellow jackets, white-faced hornets, yellow-faced hornets) may be necessary as it is very efficacious in preventing further severe allergic reactions to flying insects if stung again. In addition, a self-injectable epinephrine device (e.g., EpiPen, Auvi-Q, Adrenaclick) or intranasal epinephrine spray (e.g., Neffy) should be prescribed to anyone with a history of venom sensitivity and told to go to the closest emergency room if the epinephrine is used. Another allergen lurking in the summertime is poison ivy. Together with poison oak and poison sumac, these plants are notorious for causing severe itching and rashes to sensitive individuals. In addition to the person who enjoys doing various activities outside, certain “outdoor” professions (e.g., construction workers, firefighters, farmers, landscapers) are at a higher risk to develop poison ivy, poison oak, poison sumac, or other plant-induced contact dermatitis than other professions where workers are primarily based indoors. Certain groups of people or individuals are more prone to developing an allergy to sunscreen. Individuals who work outdoors on a regular basis such as farmers or construction workers, people with sun-damaged skin, and persons applying sunscreen to areas of damaged skin are more at risk. Females are more affected primarily because they are more prone to using cosmetics that can contain potentially irritating substances. One should also remember that food allergies are always a problem, but may be a bigger problem if one is outdoors in a remote location far from an urgent care center or hospital. Thus, campers, hikers, and nature lovers should be very in tune to what foods they consume and avoiding those foods they are not supposed to eat. They should also carry their self-injectable epinephrine device (e.g., EpiPen, Auvi-Q, Adrenaclick) or intranasal epinephrine spray (e.g., Neffy). Black & Kletz Allergy has board certified allergy and immunology physicians as well as a trained staff experienced in both the diagnosis and treatment of atopic diseases such as allergic rhinitis (i.e., hay fever), allergic conjunctivitis (i.e., eye allergies), asthma, contact dermatitis (e.g., poison ivy, poison oak, poison sumac, sunscreen allergy), and food allergies. We treat both adults and children and we have 3 convenient office locations in the Washington, DC, Northern Virginia, and Maryland metropolitan area. Black & Kletz Allergy has offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. We have on-site parking at each location and the Washington, DC and McLean offices are Metro accessible. There is a free shuttle that runs between the McLean, VA office and the Spring Hill metro station on the silver line. Please call us if you, a family member, a friend, or a colleague suffer from any one of these maladies or any other allergic or immunologic problem and want to be evaluated and treated. You may also click Request an Appointment and we will respond within 24 hours of the next business day. The allergy doctors at Black & Kletz Allergy strive to keep up with the newest allergy and asthma treatment modalities so that cutting edge medicine is always at the forefront and available to our patients.Now that Summer is almost here, people tend to spend a lot of time outdoors.  Whether it be going to the beach, swimming at the neighborhood pool, playing baseball or softball, having a picnic, fishing, hiking, riding bicycles, gardening, or any other outside activity, people are more likely to be outdoors now than in any other season of the year.  Since the general public is outdoors more in the Summers, it should be noted that there are a lot of outdoor allergens that they are being exposed to when outside. The most obvious allergens that come to mind are the pollens, which are associated with late Spring and Summer.  In the Washington, DC, Northern Virginia, and Maryland metropolitan area, tree, grass, and ragweed pollens make up the bulk of the pollens that tend to cause allergy symptoms in susceptible individuals.  Tree pollen generally is released at the end of February and it lasts until late May or early June.  Grass pollen, on the other hand, usually begins to pollinate in late April or early May and lasts until the end of August.  Ragweed, a type of weed that is quite bothersome to some individuals, generally begins to pollinate in mid-August and ends after the first frost which is usually in late October. The classic symptoms associated with pollen allergies typically include one or more of the following symptoms:  sneezing, runny nose, nasal congestion, post-nasal drip, itchy nose, itchy mouth, itchy eyes, watery eyes, redness of the eyes, snoring, headaches, and/or sinus congestion.  In those individuals with asthma whose asthma is exacerbated by pollen, chest tightness, wheezing, coughing, and/or shortness of breath may also ensue. In addition to pollens as a source for summertime allergies, one must be cautious of flying insects, particularly if that person has a history of hives or a systemic allergic reaction resulting from an insect sting.  In the Washington, DC metro area, bees, wasps, yellow jackets, white-faced hornets, and yellow-faced hornets are the major flying insects that inject venom into humans.  Some individuals will naturally develop an immune response to further stings with that species of insect.  As a result, when that person is subsequently stung with the insect that they are allergic to, an allergic reaction occurs which may be mild, moderate, or severe.  Severe allergic reactions to flying insects due to venom allergy may be life-threatening.  Anyone who has a history of hives and/or a systemic reaction to a flying insect, whether it be mild, moderate, or severe, should seek a board certified allergist to get evaluated.  Allergy blood testing or allergy skin testing is warranted and depending on the results of the tests, a course of venom immunotherapy (i.e., allergy shots to venomous flying insects such as bees, wasps, yellow jackets, white-faced hornets, yellow-faced hornets) may be necessary as it is very efficacious in preventing further severe allergic reactions to flying insects if stung again.  In addition, a self-injectable epinephrine device (e.g., EpiPen, Auvi-Q, Adrenaclick) or intranasal epinephrine spray (e.g., Neffy) should be prescribed to anyone with a history of venom sensitivity and told to go to the closest emergency room if the epinephrine is used. Another allergen lurking in the summertime is poison ivy.  Together with poison oak and poison sumac, these plants are notorious for causing severe itching and rashes to sensitive individuals.  In addition to the person who enjoys doing various activities outside, certain “outdoor” professions (e.g., construction workers, firefighters, farmers, landscapers) are at a higher risk to develop poison ivy, poison oak, poison sumac, or other plant-induced contact dermatitis than other professions where workers are primarily based indoors. Certain groups of people or individuals are more prone to developing an allergy to sunscreen.  Individuals who work outdoors on a regular basis such as farmers or construction workers, people with sun-damaged skin, and persons applying sunscreen to areas of damaged skin are more at risk.  Females are more affected primarily because they are more prone to using cosmetics that can contain potentially irritating substances. One should also remember that food allergies are always a problem, but may be a bigger problem if one is outdoors in a remote location far from an urgent care center or hospital.  Thus, campers, hikers, and nature lovers should be very in tune to what foods they consume and avoiding those foods they are not supposed to eat.  They should also carry their self-injectable epinephrine device (e.g., EpiPen, Auvi-Q, Adrenaclick) or intranasal epinephrine spray (e.g., Neffy). Black & Kletz Allergy has board certified allergy and immunology physicians as well as a trained staff experienced in both the diagnosis and treatment of atopic diseases such as allergic rhinitis (i.e., hay fever)allergic conjunctivitis (i.e., eye allergies)asthmacontact dermatitis (e.g., poison ivy, poison oak, poison sumac, sunscreen allergy), and food allergies.  We treat both adults and children and we have 3 convenient office locations in the Washington, DC, Northern Virginia, and Maryland metropolitan area.  Black & Kletz Allergy has offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  We have on-site parking at each location and the Washington, DC and McLean offices are Metro accessible.  There is a free shuttle that runs between the McLean, VA office and the Spring Hill metro station on the silver line.  Please call us if you, a family member, a friend, or a colleague suffer from any one of these maladies or any other allergic or immunologic problem and want to be evaluated and treated.  You may also click Request an Appointment and we will respond within 24 hours of the next business day.  The allergy doctors at Black & Kletz Allergy strive to keep up with the newest allergy and asthma treatment modalities so that cutting edge medicine is always at the forefront and available to our patients.
Histamine Intolerance

May 28, 2025 | Black & Kletz Allergy

Histamine IntoleranceHistamine is a biogenic amine (i.e., an organic compound made up of carbon and nitrogen bonds) with several biological effects across different types of cells, mediated through the activation of histamine receptors.  Histamine is normally present within mast cells and other similar cell types such as basophils.  Mast cells are cells of the connective tissue that contain many granules rich in histamine and other chemicals.  Histamine is also present in various types of food, such as cheese, fermented foods, wine, spinach, some types of fish and meats. During an allergic reaction, the mast cells are triggered to release their “granules” which contain histamine and other active substances (e.g., leukotrienes, prostaglandins) into the bloodstream. It is these substances that are responsible for causing allergic symptoms which vary depending on the organ and the sensitivity of the allergic individual. H1 (histamine 1) receptors are predominantly present in the skin and mucous membranes.  When these receptors are activated by histamine, they result in allergic symptoms such as itching (i.e., pruritus), rashes, flushing, hives (i.e., urticaria), and/or soft tissue swellings (i.e., angioedema).  Stimulation of the H1 receptors in the mucous membranes by histamine causes allergic symptoms such as sneezing spells, nasal congestion, runny nose, post-nasal drip, itchy throat, sinus congestion, headaches, itchy eyes, watery eyes, and/or redness of the eyes. Allergies and excessive histamine release also play a role in asthma symptoms such as chest tightness, coughing,  wheezing, and/or shortness of breath.  In addition to stimulating H1 receptors, histamine also stimulates H2 receptors in the stomach and thus plays a role in acid production and digestion.  Excessive levels of histamine can lead to the overproduction of stomach acid and as a result, in can cause heartburn and other gastroesophageal reflux disease (GERD) symptoms. Histamine intolerance occurs when the body’s capacity to eliminate histamine is exceeded by the rate of histamine accumulation.  In healthy individuals, the enzyme called intestinal diamine oxidase (DAO) helps eliminate histamine that was consumed from food.  When the activity of DAO is inhibited by certain factors, the body’s ability to manage histamine is significantly affected.  Genetic mutations causing the decreased expression of the DAO enzyme and some medications are 2 factors that can reduce the effectiveness of DAO.  As a result of these factors (i.e., genetic mutations, medications), an accumulation of histamine may occur which cause symptoms that can mimic true allergic reactions.  Some examples of drugs that have been found to affect DAO’s activity include verapamil, clavulanic acid, and isoniazid, among others.  Certain mineral and vitamin deficiencies (e.g., vitamin C, copper) are also known to decrease DAO activity.  Alcohol, on the other hand, has been found to increase the release of endogenous histamine, affecting the rate of its degradation. Symptoms:  The symptoms of histamine intolerance are varied and may involve different systems of the body.
  • Skin:  pruritus, flushing, urticaria, dermatitis, and/or swelling.
  • Gastrointestinal: abdominal bloating, abdominal discomfort, gas, diarrhea and/or constipation
  • Respiratory:  runny nose, nasal congestion, post-nasal drip, itchy throat, sneezing, sinus congestion, chest tightness, coughing, wheezing, and/or shortness of breath
  • Cardiovascular:  cardiac rhythm disturbances and/or blood pressure variations
  • Neurological:  headaches
Diagnosis: There are no standardized tests to confirm the diagnosis of histamine intolerance.  The normal levels of DAO in the serum (i.e., blood) and the diagnostic levels for histamine intolerance have not been established. High DAO levels may exclude histamine intolerance, whereas low levels are quite common and not diagnostic of histamine intolerance. At this time, in the absence of clear diagnostic guidelines, the diagnosis rests primarily on clinical manifestations and therapeutic trials. Treatment:
  1. Restrict foods that contain high levels of histamine (e.g., seafood, fermented soybean products, aged cheese, avocado, chocolate, nuts, milk, legumes, certain fruits such as bananas).  Instead, substitute histamine-rich foods with foods that are low in histamine (e.g., water, fresh juices, herbal teas, bread, rice, eggs, honey).
  2. Keep a food and symptom diary for 4 to 6 weeks and eliminate the suspected foods for 4 to 6 weeks and gradually reintroduce them while closely monitoring the symptoms.
  3. Empirical trials with antihistamine drugs, though there are no randomized trials to prove the value of this treatment in addressing histamine intolerance.
  4. Mast cell stabilizer medications such as cromolyn and ketotifen may be helpful in selective cases.
  5. The approach of supplementation with over-the-counter DAO enzyme in order to reduce excessive levels of histamine in the serum is controversial and there are no standardized guidelines available regarding the dosage.
  6. Supplementing with minerals and vitamins such as copper, zinc, vitamin C, and/or vitamin B6 in the case of a known deficiency, malnutrition, or restrictive diet, may be beneficial, if approved by one’s physician.
Note:  The American Academy of Allergy, Asthma and Immunology does not currently recognize histamine intolerance as a condition.  Before implementing any of the above “treatments,” one’s symptoms should be discussed with one’s allergist or primary care physician.  The treatment recommendations listed above should only be adhered to if one’s doctor agrees with them in that specific individual’s situation. If you suffer from symptoms of histamine intolerance or any other food or environmental allergies, please call us in order to schedule an appointment with one of our board-certified allergy doctors at Black & Kletz Allergy.  You may also click Request an Appointment and we will respond within 24 hours by the next business day.  All 3 of our offices have on-site parking and the Washington, DC and McLean, VA offices are Metro accessible.    The McLean office has a complementary shuttle that runs between our office and the Spring Hill metro station on the silver line.  The allergy doctors of Black & Kletz Allergy diagnose and treat both pediatric and adult patients.  The allergy specialists at Black & Kletz Allergy have been helping the residents and visitors of the Washington, DC, Northern Virginia, Maryland metropolitan area for more than 50 years and are pleased to help you improve the quality of your life by alleviating those unwanted and annoying allergy and asthma symptoms.

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McLean, VA Location

1420 SPRINGHILL ROAD, SUITE 350

MCLEAN, VA 22102

PHONE: (703) 790-9722

FAX: (703) 893-8666

Washington, D.C. Location

2021 K STREET, N.W., SUITE 524

WASHINGTON, D.C. 20006

PHONE: (202) 466-4100

FAX: (202) 296-6622

Manassas, VA Location

7818 DONEGAN DRIVE

MANASSAS, VA 20109

PHONE: (703) 361-6424

FAX: (703) 361-2472


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