Some people get an itchy or tingling mouth every time they eat raw fruits or vegetables. While this can easily be confused with experiencing a conventional food allergy, this response is more likely to be a case of oral allergy syndrome (OAS). OAS is an allergic reaction linked to cross-reactivity between certain pollens and foods. An Atlanta allergist can help identify symptom triggers and the right way to manage them.
5 Differences Between Oral Allergy Syndrome and Food Allergies
Oral allergy syndrome is a mild allergic reaction that affects some people who have seasonal pollen allergies. It’s also called pollen food allergy syndrome because of similarities between the proteins found in some fruits, vegetables and nuts and those in pollen. Although it involves a reaction to food, it differs from true food allergies in several important ways.
1. Oral Allergy Syndrome Begins With a Pollen Allergy
Reactions to specific raw fruits and vegetables only happen after the immune system has become sensitized to pollen – most often birch, ragweed or grass. The process is called cross-reactivity, where the immune system mistakes the food protein for the pollen allergen. But unlike a typical food allergy, a person is not developing a new allergy to the food. The pollen allergy comes first, and the food reaction follows as a result.
2. Symptoms Usually Affect the Mouth and Throat
OAS symptoms usually appear within minutes of eating the trigger food. These symptoms include itching, tingling or mild swelling of the lips, tongue, mouth or throat. In most cases, reactions are limited to the areas that touched the food. Food allergies such as those involving peanuts, tree nuts and shellfish trigger symptoms throughout the body, ranging from coughing and breathing difficulties to hives and vomiting.
3. Raw and Cooked Foods Can Cause Different Reactions
Most OAS symptoms are caused by eating raw foods. When the same foods are cooked or heated, they often will not trigger a response. This is because cooking and heating food changes its protein structure, so it’s less likely to confuse the immune system. Note that a standard food allergy does not work the same way, as with an allergy both raw and cooked foods are likely to cause symptoms. One of the benefits of allergy testing for oral allergy syndrome is the ability to confirm how a person reacts to the food in raw and cooked forms. Visiting your allergist for in-office testing is much preferred to experimenting at home.
4. Food Reactions Can Vary by Season and Pollen Type
For a person with OAS, trigger foods will depend on the pollen they are allergic to. Birch pollen, for example, is linked to apples, pears, peaches, cherries, carrots and hazelnuts. Grass pollen is associated with foods like melons, tomatoes, oranges and peaches. While proteins in these raw foods are structurally similar to those in pollen, it does not mean that every associated food will trigger a reaction.
5. Anaphylaxis Is Uncommon but Still Possible
Allergies to peanuts, tree nuts and shellfish can cause anaphylaxis, which can lead to severe breathing difficulties, a drop in blood pressure and loss of consciousness. After a food allergy diagnosis, an allergist often prescribes epinephrine to anyone at risk. Most OAS symptoms are mild and pass fairly quickly. Plus, an OAS reaction rarely causes anaphylaxis, though it’s not impossible. When you’re unsure about a possible food allergy, an allergist can test for multiple allergens and create a food allergy treatment plan so patients are prepared for an emergency reaction.
Visit Our Oral Allergy Syndrome Specialists in Atlanta
For help managing the symptoms of oral allergy syndrome visit Chacko Allergy, Asthma and Sinus Center. We provide food allergy testing and treatment at locations throughout the Atlanta area. Call (678) 668-4688 or request an appointment.
