Oral allergy syndrome, also known as pollen-food syndrome, is a cross-reaction food allergy that causes an itching, allergic reaction to the lips, mouth, tongue, and throat when eating raw fruits, vegetables, and nuts.
A cross-reaction is when the body gets confused and reacts to something it shouldn’t. In the case of oral allergy syndrome, when you eat raw fruits, vegetables, or nuts the body gets confused and thinks you are eating pollen (strange!) and causes an allergic reaction intended for pollen.
Because oral allergy syndrome is caused by pollen allergies, you may only notice it when your pollen allergies are bothering you. The pollens that cause pollen allergies are usually: tree pollens in the spring, grass pollens in the summer, and weed pollens in the fall. It is also possible to have symptoms all year, especially if you have a grass pollen allergy.
Who is susceptible?
Oral allergy syndrome is seen in people who have pollen allergies or hay fever. It is most commonly diagnosed in older children, teenagers, and adults, and is very rare in babies and young children.
What are the symptoms?
Oral allergy syndrome usually is a mild reaction but in rare cases can worsen and become a severe reaction that causes difficulty breathing or anaphylaxis. The most common symptoms are: itching and burning of the mouth, lips, tongue, and throat; water, itchy eyes; a runny nose; and sneezing.
These symptoms will usually happen within minutes of eating the offending food and last for several minutes though it is possible to have symptoms up to an hour after eating the offending food. More serious and less common symptoms are: rash or hives; lip, tongue, or throat swelling; nausea and vomiting; diarrhea; reflux; stomach ache; and difficulty breathing and wheezing.
What foods cause oral allergy syndrome?
There are various foods that have cross-reactions with pollen but a person with oral allergy syndrome may only react to one, several, or no particular food. Here is a list of pollens and their offending foods:
- Tree pollens: almond, aniseed, apples, apricots, caraway, carrots, celery, cherries, coriander, fennel, hazelnut, kiwi, parsley, peaches, peanuts, pears, plums, and soy.
- Grass pollens: cantaloupe, honeydew, oranges, peanuts, swiss chard, tomatoes, watermelon, and white potatoes.
- Mugwort (weed) pollen: aniseed, bell pepper, black pepper, broccoli, cabbage, caraway, carrot, cauliflower, celery, chamomile, coriander, fennel, garlic, mustard, onion, and parsley.
- Ragweed (weed) pollen: banana, cantaloupe, cucumber, honeydew, watermelon, and zucchini.
How to know if you have oral allergy syndrome?
Oral allergy syndrome can be diagnosed by a licensed physician, such as an allergist. Diagnosis is done by a combination of your medical history, allergy symptoms, and testing. The most common test used to diagnose oral allergy syndrome is a skin test.
A skin test is done in the doctor’s office and can usually produce results within 15 minutes. A skin test is done by taking a liquid version of your offending allergen and pricking into your skin on your arms or back.
If you have an allergy, the site that was pricked will usually have a reaction such as redness, swelling, itching or burning. In oral allergy syndrome, doctors are not looking for you to have a reaction to food but rather to pollen because it is really a pollen allergy not a food allergy.
How do I treat oral allergy syndrome?
There is only one way to eliminate all oral allergy syndrome symptoms and that is through avoiding your offending food. That means if you react to “apples” you avoid all apples whether cooked or raw. This also means that you need to avoid the food when dehydrated or “hidden” in other foods.
For example, bell peppers when dried are used to make paprika. Paprika is used for seasoning in cooking but also “hidden” in foods for flavoring and coloring such as mayonnaise, barbeque sauce, muenster cheese, margarine, and hot sauce. While the safest and best treatment is avoiding the offending food that may be difficult or impossible to do. Here is a few other treatment options for oral allergy syndrome:
- Avoid eating the food raw. Since oral allergy syndrome symptoms happen usually when the offending food is eaten raw you may have fewer symptoms if you eat the food peeled, canned, processed, pasteurized, frozen, heated, or cooked. Some people experience fewer symptoms doing things such as peeling an apple or microwaving a banana for 10-15 seconds. Though this may sound “strange” just by changing the way you eat the food can keep the body from thinking you’ve come in contact with pollen. Unfortunately, in the case of celery and nuts this doesn’t work and can still cause symptoms.
- Take antihistamines. While there is no medication for oral allergy syndrome antihistamines, such as those used for hay fever and pollen allergies, can help relieve some of the symptoms. Some people have found if they start taking antihistamines for several weeks before the pollen they are allergic to is blooming they will have fewer symptoms. Though, it isn’t the best or safest idea to take antihistamines just so you can eat your offending food.
- Allergy shots. Allergy shots are not typically prescribed for oral allergy syndrome but rather for pollen allergies and hay fever. By treating the pollen allergies and hay fever some people have found they are less likely to have oral allergy syndrome symptoms.
- Don’t do anything. This is not the best treatment, but if you only have mild symptoms it may be the most convenient method. If you do choose to continue to eat your offending food, the best advice would be to avoid eating it in large amounts and try to avoid it when the pollen you are allergic to is blooming. This is not a safe option if you have had anaphylaxis to the offending food before. This is also unsafe to do to foods that have a high risk of causing anaphylaxis, such as: peanuts, tree nuts, and mustard.
Remember, however you choose to diagnose, treat, and cope oral allergy syndrome, consult with your doctor to make sure it is the best and safest option for you. In some cases it may also be necessary to consult with a dietician to make sure that the changes in your eating still lead to a healthy, balanced diet.