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
- Abdominal pain
- Nausea and/or vomiting
- Skin rashes [i.e., hives (urticaria)]
- Swelling of the lips, tongue, and/or throat (i.e., angioedema)
- Shortness of breath
- Drop in blood pressure
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.