Alpha-Gal Syndrome Update

August 18, 2025 | Black & Kletz Allergy

Over 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 (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

Pet 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 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:

• 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:

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.

Prurigo Nodularis

June 27, 2025 | Black & Kletz Allergy

Prurigo 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.

• 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.

Summer Outdoor Allergies

June 16, 2025 | Black & Kletz Allergy

Histamine Intolerance

May 28, 2025 | Black & Kletz Allergy

Histamine 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.

Allergies to Pollen

May 23, 2025 | Black & Kletz Allergy

Individuals with pollen allergies may be affected throughout the year, depending on where they live or travel.  In the Washington, DC, Northern Virginia, and Maryland metropolitan area, pollen allergies are bothersome to allergic individuals generally from late February through the first frost, which is usually at the end of October.  In this region, trees are the first to pollinate, generally releasing tree pollen from the end of February through the end of May.  The pollen peaks in April and is recognized by everyone when their cars appear “yellow” in color.  The yellowish color of the cars is due to the yellow-colored tree pollen falling on and sticking to all of the motor vehicles that dominate the Washington, DC metro area.  Grass pollen is released after tree pollen, usually beginning in early May and continuing until the end of the Summer.  Lastly, ragweed begins to pollinate in mid-August and it lasts until the first frost, which as mentioned above, ends in late October. It is interesting to note that a short time after the trees begin to pollinate, the cherry trees begin to flower.  People both familiar and unfamiliar with allergies often misassociate the two events and wrongly conclude that the cherry trees are causing their allergies because of the timing of the two events.  Notwithstanding, the media tends to get it wrong, as they tend to associate the two occurrences, which further confuses the issue.  The truth is that the flowering cherry trees are not causing the hay fever (i.e., allergic rhinitis) and/or the eye allergies (allergic conjunctivitis) symptoms that the allergy sufferers are feeling, but rather it is the non-flowering trees that are the culprit.  In general, flowering trees and bushes do not generally cause allergy symptoms.  Individuals who have allergy symptoms from tree pollen need to inhale the pollen in order to develop the usual symptoms of allergic rhinitis.  The pollen of flowering trees and bushes is heavy compared with non-flowering trees and is not wind-dispersed as a result.  The pollen of non-flowering trees and bushes, on the other hand, is light in weight and thus easily dispersed by the wind.  As a result, the pollen from the non-flowering trees (“ugly trees”) and bushes (“ugly bushes”) are the pollen that individuals become sensitized to and thus allergic to due to the fact that they are breathing in this pollen causing the immune system to be affected.  In certain individuals, the immune system decides that it doesn’t like the tree pollen allergens and mounts a defensive response.  This allergic reaction involves the production on inflammatory mediators and chemicals.  These chemicals (e.g., histamine, leukotrienes, prostaglandins), which are released into the bloodstream, cause the annoying symptoms that allergic individuals dread every pollen season. The classic symptoms experienced by most people afflicted with allergic rhinitis or hay fever may include sneezing, itchy nose, itchy throat, nasal congestion, runny nose, post-nasal drip, itchy eyes, watery eyes, redness of the eyes, itchy ears, clogged ears, sinus pressure, fatigue, headaches, snoring, coughing, chest tightness, wheezing, and/or shortness of breath. The diagnosis of pollen allergies begins with a comprehensive history and physical examination.  In the history, it is important for the allergist to ascertain if the patient experiences hay fever symptoms or worsening hay fever symptoms in the months where pollination takes place, mostly in the Spring and/or Fall.  The next step is usually allergy skin testing (or blood testing) to environmental allergens in order to see if the individual is allergic and to what extent. Avoidance measures are usually the first things recommended to a person with pollen allergies, assuming that individual wants or is able to avoid pollen.  Many things can be done, but it is up to the patient to follow the recommendations by the allergist.  Some of these preventive measures are as follows: 1.     Turn on air conditioning. 2.     Change air filters often (i.e., monthly). 3.     Wash pets after they go outdoors. 4.     Avoid mowing lawns and yard work or wear a filtered mask. 5.     Shower, wash hair, and change clothing after coming back indoors. 6.     Drive a car that has an air filter. 7.     Re-circulate air in car so it doesn’t come in from the outdoors. 8.     Keep sunroofs and windows closed in your vehicle. The treatment of patients who have pollen allergies depends on the duration and the severity of symptoms.  Oral antihistamines are usually the first line of defense.  In individuals who need more intensive treatment, oral decongestants, nasal corticosteroids, nasal antihistamines, nasal anticholinergics, nasal mast cell stabilizers, nasal decongestants, and oral leukotriene antagonists may be utilized.  In patients exhibiting ocular symptoms, eye drops containing antihistamines, leukotriene antagonists, and/or mast cell stabilizers are available.  Asthmatic patients may also be treated with inhaled bronchodilators, inhaled corticosteroids, inhaled anticholinergics, and biologicals.  Allergy injections (i.e., allergy shots, allergy immunotherapy, allergy desensitization, allergy hyposensitization) are very efficacious as they help in 80-85% of individuals with allergic rhinitis, allergic conjunctivitis, and/or asthma.  The average patient is on allergy injections for 3-5 years. Pollen season is upon us and the Spring pollen is blanketing the landscape in the Washington, DC metropolitan area.  The board certified allergy doctors at Black & Kletz Allergy have 3 locations in the Washington, Northern Virginia, and Maryland metropolitan area.  We have offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA.  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 adult and pediatric patients.  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.  Our allergists at Black & Kletz Allergy have been helping patients with hay fever, eye allergies, asthma, sinus disease, generalized itching (pruritus), hives (i.e., urticaria), eczema (i.e., atopic dermatitis), anaphylaxis, medication allergies, food allergies, insect sting allergies, and immunological disorders for more than 5 decades.  If you suffer from allergies, it is our goal to improve your quality of life by decreasing or stopping your undesirable allergy symptoms.

Is Primatene Mist Good for Asthma?

April 15, 2025 | Black & Kletz Allergy

There are a few over-the-counter (OTC) medications that some patients with asthma and other respiratory conditions occasionally use. One of them is an inhaler called Primatene Mist. Primatene Mist contains epinephrine (i.e., adrenaline) in an inhalable form. Though it is the same drug that is in an EpiPen, Auvi-Q, Adrenaclick, and other self-injectable epinephrine devices as well as the nasal spray, Neffy, used to treat acute allergic emergencies such as anaphylaxis, Primatene Mist does not help in those situations and should not be used. Although Primatene Mist became available in 1967, the FDA took it off the market in 2011, as it contained propellants called chlorofluorocarbons (CFC’s) which are harmful to the environment as they deplete ozone from the atmosphere. However, Primatene mist was recently reintroduced into the market with a newer propellant called hydrofluoroalkanes (HFA’s), which are environment friendly. Primatene Mist temporarily opens up the airways in the lungs thus offering a very short-term relief from shortness of breath and/or wheezing. It is approved only for individuals with an established prior diagnosis of asthma. It is used for the temporary relief of mild symptoms of intermittent asthma in patients aged 12 years or older and should not be used as a replacement for prescription asthma medications. Primatene Mist can do more harm than good if used for a chronic cough, for instance, without a known cause. The risks of Primatene Mist usage include masking of the symptoms without addressing the underlying cause. The symptoms of chest tightness, wheezing, cough, and/or shortness of breath should lead to the proper evaluation in order to establish the reason behind the symptoms. In cases of asthma, the underlying cause could be long-standing inflammation of the lungs. Proper evaluation and management should include the assessment of the lung function in addition to trying to control the causative factors. Uncontrolled inflammation can result in damage to the lung tissues and a reduction in lung capacity over time, which can be irreversible. Several deaths are reported each year in the USA due to uncontrolled asthma. Deaths also occur in cases of mild asthma with acute exacerbations. Primatene Mist is also associated with undesirable side effects such as palpitations, increase in blood pressure, nervousness, etc. In the elderly and in individuals with certain conditions such as heart problems, Primatene Mist may be harmful as epinephrine may worsen their underlying conditions. There is also concern for misuse or abuse. Primatene Mist may make the individual feel better temporarily when in fact the underlying reason for the exacerbation of the asthma goes unchecked, leading to a worse outcome overall because the individual did not seek the proper care. Albuterol, a prescribed alternative medication, is typically used for the quick relief of asthma symptoms. It is a bronchodilator which acts by relaxing the muscles around the airways so that they can open up better making it easier to breath. Primatene Mist is less potent and has a much shorter duration of action than albuterol, and thus not preferred. Primatene Mist is not recommended for severe asthma or as a long-term treatment. It should not be used in children under the age of 12 years old. There is a defined role for albuterol in relieving symptoms while also controls the underlying cause(s) with anti-inflammatory medications. In fact, there is an albuterol inhaler that has a corticosteroid added to it in order to give the medication an anti-inflammatory benefit when treating the symptoms of asthma. This medication is called AirSupra and it contains both albuterol and the corticosteroid called budesonide. It should also be noted that the national and international guidelines by organizations such as the National Institutes of Health (NIH) and the Global Initiative for Asthma (GINA) do not recommend using Primatene Mist. The board certified allergists at Black & Kletz Allergy are always available for our patients to ask any questions that they may have regarding asthma or allergies. We have been treating adult and pediatric patients with asthma for more than 50 years. In addition, we diagnose and treat individuals with allergic rhinitis (i.e., hay fever), allergic skin conditions such as urticaria (i.e., hives) and atopic dermatitis (i.e., eczema), eosinophilic disorders, insect sting allergies, medication allergies, and immune disorders. We have 3 office locations in the Washington, DC, Northern Virginia, and Maryland metropolitan area with offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. All of our offices offer on-site parking and 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. If you would like to be evaluated today for asthma or any other allergic or immunologic problem, please call us today. You may also click Request an Appointment instead and we will respond to your request within 24 hours by the next business day. The allergy specialists at Black & Kletz Allergy pride themselves in providing the highest quality asthma and allergy care in the Washington, DC metro area.

Pollen Food Allergy Syndrome Revisited

April 10, 2025 | Black & Kletz Allergy