Oral allergy syndrome what can i eat

There are no tests specifically for oral allergy syndrome. However, an environmental allergy test can identify allergens that may be the culprit. Patients diagnosed with oral allergy syndrome also typically own histories of reactions to suspect unused foods. An allergist/immunologist can assist you determine if you own oral allergy syndrome or other more serious food allergies.

What It Is The Cause?

Oral allergy syndrome occurs when unused fruits and vegetables cause local allergy symptoms, such itching of the mouth or throat with eating. Generally more severe or generalized allergy symptoms, such as hives, trouble breathing, or vomiting, do not happen with oral allergy syndrome but can happen with other more serious food allergies.

This local reaction happens because the immune system becomes confused. The proteins in certain  unused fruits and vegetables are structurally similar to the pollens that cause hay fever. The immune system reacts to the similar proteins in these unused foods, love it does pollens, causing allergy symptoms.

Signs and symptoms

OAS sufferers may own any of a number of allergic reactions that generally happen extremely rapidly, within minutes of eating a trigger food.

The most common reaction is an itching or burning sensation in the lips, mouth, ear canal, or pharynx. Sometimes other reactions can be triggered in the eyes, nose, and skin. Swelling of the lips, tongue, and uvula, and a sensation of tightness in the throat may be observed. If a sufferer swallows the food, and the allergen is not destroyed by the stomach acids, it is likely that there will be a reaction from histamine release later in the gastrointestinal tract.

Oral allergy syndrome what can i eat

Vomiting, diarrhea, severe indigestion, or cramps may occur.[5] Rarely, OAS may be severe and present as wheezing, vomiting, hives, low blood pressure,[6] or anaphylaxis.[7]


OAS produces symptoms when an affected person eats certain fruits, vegetables, and nuts. Some individuals may only show allergy to one specific food, and others may show an allergic response to numerous foods.[8]

Individuals with an allergy to tree pollen may develop OAS to a variety of foods. While the tree pollen allergy has been worked out, the grass pollen is not well understood. Furthermore, some individuals own severe reactions to certain fruits and vegetables that do not drop into any specific allergy category.

When tropical foods initiate OAS, allergy to latex may be the underlying cause.[9]

Because the allergenic proteins associated with OAS are generally destroyed by cooking, most reactions are caused by eating raw foods. The main exceptions to this are celery and nuts, which may cause reactions even after being cooked.[citation needed]

Cross reactions

Allergies to a specific pollen are generally associated with OAS reactions to other certain foods.

Oral allergy syndrome what can i eat

For instance, an allergy to ragweed is associated with OAS reactions to banana, watermelon, cantaloupe, honeydew, zucchini, and cucumber. This does not mean that every sufferers of an allergy to ragweed will experience adverse effects from every or even any of these foods. Reactions may be associated with one type of food, with new reactions to other foods developing later. However, reaction to one or more foods in any given category does not necessarily mean a person is allergic to every foods in that group.

  1. Alder pollen:almonds, apples, celery, cherries, hazel nuts, peaches, pears, parsley, raspberry, strawberry
  2. Birch pollen:almonds, apples, apricots, avocados, bananas,[10]carrots, celery, cherries, chicory,[11]coriander, fennel, fig,[12]hazel nuts, kiwifruit, nectarines, parsley, parsnips, peaches, pears, peppers, plums, potatoes, prunes, soy, strawberries, wheat; Potential:walnuts[13]
  3. Mugwort pollen :carrots, celery, coriander, fennel, parsley, peppers, sunflower
  4. Grass pollen:fig,[12]melons, tomatoes, oranges, celery, peach[13]
  5. Ragweed pollen :banana, cantaloupe, cucumber, green pepper, paprika, sunflower seeds/oil, honeydew, watermelon, zucchini, echinacea, artichoke, dandelions, honey (if bees pollinate with pollen from wild flowers), hibiscus or chamomile tea
  1. Possible cross-reactions (to any of the above): berries (blueberries, raspberries, etc.), citrus (oranges, lemons, etc.), grapes, mango, figs, peanut, pineapple, pomegranates, watermelon

Managing Symptoms

The best way to manage symptoms of oral allergy syndrome is to avoid eating the raw fruits and vegetables that cause an allergic reaction, particularly during the pollen season.

Baking or microwaving these fruits and vegetables can prevent symptoms because heat breaks below the proteins responsible for oral allergy syndrome.

Oral allergy syndrome what can i eat

Heating will not prevent reactions in other more serious food allergies. Peeling unused fruits and vegetables may also minimize symptoms in oral allergy syndrome.

If you frequently discover yourself with an itchy throat or mouth after eating unused fruits and vegetables, contact us today for an appointment. Our allergists can assist determine if you own oral allergy syndrome or other food allergies. If you own oral allergy syndrome, we will explain what foods to avoid based on the seasonal allergies you have.

Filed Under: Allergy

Oral allergy syndrome (OAS) is a type of food allergy classified by a cluster of allergic reactions in the mouth and throat in response to eating certain (usually fresh) fruits, nuts, and vegetables that typically develops in adults with hay fever.[1]

OAS is not a separate food allergy, but rather represents cross-reactivity between distant remnants of tree or weed pollen still found in certain fruits and vegetables.

Therefore, OAS is only seen in people with seasonal pollen allergies, and mostly people who are allergic to tree pollen.[2] It is generally limited to ingestion of raw fruits or vegetables.[2]

Another term used for this syndrome is pollen-food allergy. In adults up to 60% of every food allergic reactions are due to cross-reactions between foods and inhalative allergens.[3]

OAS is a Type 1 or IgE-mediated hypersensitivity, which is sometimes called a «true allergy».

The body’s immune system produces IgE antibodies against pollen; in OAS, these antibodies also bind to (or cross-react with) other structurally similar proteins found in botanically related plants.

OAS can happen any time of the year but is most prevalent during the pollen season.

Oral allergy syndrome what can i eat

Individuals with OAS generally develop symptoms within minutes of eating the food.[4]


OAS must be managed in conjunction with the patient’s other allergies, primarily the allergy to pollen. The symptom severity may wax and wane with the pollen levels.

Oral allergy syndrome what can i eat

Published pollen counts and seasonal charts are useful but may be ineffective in cases of high wind or unusual weather, as pollen can travel hundreds of kilometers from other areas.

In addition, patients are advised to avoid the triggering foods, particularly nuts.

Oral allergy syndrome what can i eat

Peeling or cooking the foods has been shown to eliminate the effects of some allergens such as mal d 1 (apple), but not others such as celery or strawberry. In the case of foods such as hazelnut, which own more than one allergen, cooking may eliminate one allergen but not the other.

Antihistamines may also relieve the symptoms of the allergy by blocking the immune pathway. Persons with a history of severe anaphylactic reaction may carry an injectable emergency dose of epinephrine (such as an EpiPen).

Oral steroids may also be helpful.

Oral allergy syndrome what can i eat

Allergy immunotherapy has been reported to improve or cure OAS in some patients. Immunotherapy with extracts containing birch pollen may benefit OAS sufferers of apple or hazelnut related to birch pollen-allergens. Even so, the increase in the quantity of apple/hazelnut tolerated was little (from 12.6 to 32.6 g apple), and as a result, a patient’s management of OAS would be limited.[14]