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Month: January 2023

Lipid Transfer Protein Allergy

Many fruits and vegetables contain substances called lipid transfer proteins (LPT’s). They are usually present in the skin and seeds of these foods. Lipid transfer proteins are also found in various nuts and some cereals. In the plant, the purpose of the lipid transfer proteins is to move the lipid molecules so the plants develop and maintain their internal and external structures.

Individuals can become sensitized to the lipid transfer proteins. As a result, people can have allergic reactions to them when exposed in the foods we consume. When this occurs, it is called lipid transfer protein allergy. When an individual is allergic to many foods containing lipid transfer proteins, it can be said that that person has lipid transfer protein syndrome.  The most common plant foods triggering these reactions include apples, grapes, peanuts, almonds, hazelnuts, walnuts, tomatoes, and dried fruit. Other foods that may also cause symptoms may include mustard seeds, sunflower seeds, chestnut, peaches, strawberry, kiwi, orange, tangerine, pear, banana, lemon, apricot, plum, raspberry, pomegranate, cherry, barley, lettuce, cabbage, corn, mulberry, asparagus, green beans, pea, celery, wheat, durum wheat, lentils, and lupin. Other foods that are known to contain lipid transfer proteins include broccoli, onion, beetroot, parsley, eggplant, parsnip, butter beans, fennel, millet, goji berry, quinces, grapefruit, blueberry, and figs.

Lipid transfer proteins are resistant to heat and to the acid in our digestive tract. This heat and acid resistance make it so that individuals can react to even well-cooked, dried, raw, and/or canned foods. For example, if someone is sensitized to the lipid transfer proteins in a grape, that person should avoid all grape-containing foods such as grape juice, wine, and raisins.

This condition is more common in adults as well as people living in Mediterranean countries. In fact, lipid transfer protein allergy is the most frequent cause of food allergy in southern Europe. It is however interesting to note that lipid transfer protein allergy has been increasingly recognized in other parts of the world.

SYMPTOMS: The symptoms of lipid transfer protein allergy usually begin within 10 to 30 minutes after eating the offending food. The symptoms may include the following:

  • Itching of the mouth and/or throat
  • Runny nose
  • Nasal congestion
  • Sneezing
  • Abdominal pain
  • Nausea and/or vomiting
  • Skin rashes [i.e., hives (urticaria)]
  • Swelling of the lips, tongue, and/or throat (i.e., angioedema)
  • Wheezing
  • Shortness of breath
  • Drop in blood pressure
  • Dizziness/Lightheadedness
  • Anaphylaxis

Some contributing factors of an allergic reaction due to eating a suspected food with lipid transfer proteins may include physical exertion, alcohol consumption, and certain medications [e.g., nonsteroidal anti-inflammatory medications (NSAID’s) such as ibuprofen or naproxen]. These factors also may delay the onset of the allergic symptoms where the allergic reaction begins after the typical 10 to 30 minute window. Exercise, alcohol, and NSAID’s can also increase the severity of the allergic reaction. There are even cases where someone can eat a plant-based food that contains lipid transfer proteins and has no allergic reaction but when combined with exercise, alcohol consumption, and/or NSAID exposure, that individual may experience an allergic reaction.

DIAGNOSIS: The diagnosis of this condition involves a comprehensive history and physical examination. Special emphasis should be targeted towards getting a detailed record of the patient’s food intake. Maintaining food and symptom diaries are extremely useful in helping to establish the diagnosis. The food and symptom diaries should be supplemented with allergy skin prick testing with suspected food antigens and/or laboratory evaluation when needed.

DIFFERENTIAL DIAGNOSIS: The differential diagnosis includes other food-induced allergic reactions such as pollen-food allergy syndrome (i.e., oral allergy syndrome) and food-dependent exercise-induced urticaria/anaphylaxis (FDEIA).

TREATMENT: Once the diagnosis is confirmed, avoidance of all forms of the plant food including raw, cooked, and processed forms of the food is essential in order to minimize the risk of severe reactions.

Individuals diagnosed with lipid transfer protein allergy will also be prescribed a self-injectable epinephrine device (e.g., EpiPen, Auvi-Q, Adrenaclick) which is to be used in the case of a systemic reaction following an inadvertent exposure to the offending food. It should be stressed that if an individual uses a self-injectable epinephrine device, that person should go immediately to the closest emergency room.

The board certified allergy specialists at Black & Kletz Allergy will promptly respond to any questions you may have regarding food allergies or any other allergic or immunologic disorder. Black & Kletz Allergy has been treating food allergies for many years and we have offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA. We have been serving the Washington, DC, Northern Virginia, and Maryland metropolitan area for over 50 years and treat both pediatric and adult patients. All 3 offices at Black & Kletz Allergy 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 are concerned that you may have a food allergy or sensitivity or any other allergic or immunologic condition such as allergic rhinitis (i.e., hay fever), asthma, sinus disease, medication allergies, flying insect allergies, or hives (i.e., urticaria), please call us to schedule an appointment. You may also click Request an Appointment and we will respond within 24 hours by the next business day. At Black & Kletz Allergy, we strive to improve the quality of life in allergic individuals using state-of-the-art medicine in a professional and compassionate setting.

Update on Dog, Cat, and Other Pet Allergies

In the U.S., dogs are the most common pets. According to the American Veterinary Medical Association, approximately 77 million pet dogs are living in the country spread around roughly 49 million homes. This means that each dog-owning household has an average of 1.5 dogs. The most common breed of dog is the Labrador Retriever. The second most common pets are cats. According to the American Veterinary Medical Association, there are about 32 million homes in the U.S. with cats comprising of approximately 59 million cats in total. Thus, the average cat-owning home has an average of 1.8 cats. The most common breed of cat is the Ragdoll. Fish, birds (e.g., parakeets, cockatiels, parrots), reptiles (e.g., lizards, turtles, snakes, geckos), rabbits, poultry (e.g., chickens, ducks, turkeys, geese), hamsters, guinea pigs, and ferrets round off the top 10 most common pets in the U.S. in that order. Overall, about 70% of homes have at least one pet. The number of pet-owning households continues to rise compared with ownership in the past.

It should also be noted that approximately 4 million households’ own horses. Horses do not normally live in people’s homes, but they still may be rather allergenic. In recent years, it has become fashionable to own miniature horses, which in some cases, do live in their owner’s home. Living with a horse in one’s house is probably not a good idea, but for those who are allergic to horses, it is especially ill-advised.

Whereas Wyoming is the top state for pet ownership at 71%, Idaho residents have the greatest number of dogs owners at approximately 59%. In contrast, Washington, DC has the least number of pet-owning households at 39%. Of note, 46% of Vermont residents have cats in their home making it the highest in the nation.

In general, a pet allergy is caused by an allergic reaction to specific proteins that are only found on the pet in question. The classic symptoms of pet allergies may include sneezing, runny nose, nasal congestion, post-nasal drip, sinus congestion, itchy nose, itchy throat, itchy eyes, watery eyes, red eyes, chest tightness, coughing, wheezing, and/or shortness of breath. The diagnosis of a pet allergy is done by taking a comprehensive history and physical examination of the patient in combination with allergy testing (i.e., blood tests, skin tests). Once the diagnosis is made, the best approach is prevention. If an individual can avoid being exposed to the pet, no other treatment is generally needed. If they must be exposed or refuse to avoid the animal, then the treatment may consist of oral antihistamines, oral, decongestants, leukotriene antagonists, nasal corticosteroids, nasal antihistamines, nasal anticholinergics, ocular antihistamines, ocular mast cell stabilizers, inhaled bronchodilators, inhaled mast cell stabilizers, and/or inhaled corticosteroids. For those who decide to live with their pet, allergy shots (allergy immunotherapy, allergy injections, allergy desensitization, allergy hyposensitization) may be indicated. Allergy injections are very effective as they work in 80-85% of individuals who take them. They have been given to patients for over 100 years and they are generally given for a period of 3-5 years.

People who are allergic to dogs usually have a reaction to the major protein called “Can f 1,” which is found on dogs. Specifically, the dander of dogs contains this major dog protein, Can f 1. It should be noted that the furry hair of a dog, which is not allergenic, may also transport other allergens (i.e., dust, pollens) to sensitive allergic individuals causing them to be exposed to more dust and pollens.  The dander of a dog can stick to an individual’s clothing, bedding, carpeting, etc., but with less affinity.  In addition to the dog’s dander, the Can f 1 protein is also found in a dog’s saliva and urine.  It is important to note that a dog allergy will cause perennial symptoms, unlike pollen allergies which generally affects individuals in certain seasons.

Individuals with cat allergies have a very similar situation to those with dog allergies, however, the major proteins responsible for the allergic reaction are named “Fel d 1” and “Fel d 4.” These proteins are found in the sebaceous glands of the skin (i.e., dander), the saliva, and the urine of cats. The dander of a cat tends to “stick” to things such as walls, bedding, carpeting, clothes, etc. Even with professional cleaning, it still takes a long time (i.e., up to several months) for the levels of cat protein to decrease to tolerable levels. Thus, removing a cat from one’s home for a few weeks is not long enough to determine if the cat is the problem. One misconception that is quite common is that there are “hypoallergenic cats.”  All cats have the capacity to induce allergic symptoms to cat-sensitive individuals. Some patients feel that they can tolerate short-haired cats better than long-haired cats, but studies do not support this theory. Brushing and bathing your cat regularly will however reduce the cat protein levels that cause allergic symptoms and of course is advisable.

Bird and rodent allergies are similar to other pet allergies except that in addition to the dander, the proteins responsible for the allergic reaction are also found in the urine, fecal, and feather particulates in birds and in the urine, saliva, and fecal droppings in rodents (e.g., hamsters, guinea pigs, mice, rats, gerbils, chinchillas). It is important to point out that in addition to allergies, both birds and rodents pose another threat to one’s health. Exposure to birds can cause more than 60 infections and diseases. Some of these may include avian flu, avian tuberculosis, psittacosis, salmonellosis, allergic alveolitis, campylobacteriosis, giardiasis, Newcastle disease, histoplasmosis, and cryptosporidiosis. Exposure to rodents (e.g., mice, rats) can cause many diseases as well such as the hantavirus pulmonary syndrome (HPS), tularemia, leptospirosis, salmonellosis, bubonic plague, rat-bite fever (RBF), Lassa fever, and lymphocytic choriomeningitis.

Allergies to reptiles are not common.  There have been reports of allergies to snakes, and of course there is always the possibility of an allergic reaction to the venom of certain snakes. There have also been reported cases of allergies to various reptiles, particularly iguanas. In addition to the typical allergy symptoms that occur with other pets, there seems to be more skin irritation with reptiles than with other pets.

Horse allergies are not that uncommon.  Individuals that are allergic to horses typically have similar symptoms as people with cat and/or dog allergies. 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 people are exposed to the allergenic proteins of horses. 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 board certified allergists at Black & Kletz Allergy have been diagnosing and treating pet allergies in both adults and children in the Washington, DC, Northern Virginia, and Maryland metropolitan area for more than 50 years. Black & Kletz Allergy has 3 offices in the Washington, DC metropolitan area with locations 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 Metro accessible. We offer a free shuttle that runs between our McLean, VA office and the Spring Hill metro station on the silver line. If you suffer from a pet allergy or are not sure if you do, please call us to and make an appointment at one of our conveniently located offices. Alternatively, you may click Request an Appointment and we will respond within 24 hours by the next business day. The allergy specialists at Black & Kletz Allergy are confident that we will be able to help you with your furry friends.