Are you allergic to pollen? If you are, you are not alone. Estimates are that ⅓ of all Americans have an allergy to at least one type of pollen and experience common symptoms such as itchy, watery eyes, sneezing, a runny nose, coughing or wheezing. But some people who suffer from pollen allergies also have a condition which results in other symptoms that typically occur only in the mouth. This condition is known as Oral Allergy Syndrome (OAS) and the condition is thought to exist in up to a third of all pollen allergy patients according to the American Academy of Allergy, Asthma, & Immunology (AAAAI). OAS does not usually occur in very young children; however, the syndrome is often found in older children, teens, and young adults who have been eating fruits or vegetables without problems for years and are now experiencing symptoms.
OAS is classified under a group of allergic reactions that occur in the mouth after eating specific types of (usually fresh) fruits, nuts, seeds, vegetables and even spices. The reason that OAS occurs is that the proteins found in some foods are very similar to those found in a specific pollen. For those who are allergic to a specific type of pollen, very similar or even identical proteins found in ingested foods often confuse the immune system in people with pollen allergies. Individuals with OAS usually develop symptoms within a few minutes after eating a particular food. The reactions are caused because the body attempts to battle the allergenic proteins in the same way that it battles proteins from specific hay fever-causing trees and plants in a process known as cross-reactivity. Common symptoms of OAS include tingling or uncomfortable itchiness in the mouth, throat and lips as well as slight swelling of the lips, mouth, tongue, and throat. While the symptoms are typically mild and limited to the mouth, a small percentage of those who experience OAS may exhibit body-wide symptoms and an estimated 1-2% may even be at risk for potentially life threatening condition known as anaphylaxis.
During pollen season for specific allergens, the affected individual may experience a reaction when he or she tries to eat certain raw fruits and vegetables, such as apples, melons, cherries, kiwis, celery, tomatoes, and green peppers. For example, if you are allergic to birch tree pollen, you may also find that eating fresh apples causes you to react. According to the National Institute of Allergy and Infectious Disease (NIH), "Cooking or processing easily breaks down the proteins in the fruits and vegetables that cause OAS. Therefore, OAS typically does not occur with cooked or baked fruits and vegetables or processed fruits, such as in applesauce."
Unfortunately, for those of us who live in New Orleans, Hammond or other parts of southern Louisiana, pollen season is already underway and we have one of the highest pollen counts in America, according to the Asthma and Allergy Foundation of America (AAFA). And, while OAS can occur any time of the year, cases are most prevalent during pollen season.
Some examples of foods that may cause cross-reactivity for people who have specific allergies include:
Ragweed Pollen Allergy: apples, pears, peaches, nectarines, cherries, plums, bananas, tomatoes, zucchini, sunflower seeds, dandelions melons including honeydew, cantaloupe, and watermelons and even chamomile tea.
Birch Pollen Allergy: kiwis, apples, pears, prunes, peaches, plums, cherries, coriander, fennel, parsley, celery, carrots, fennel, peppers, parsnips, walnuts, hazelnuts, and almonds.
Grass Allergy: apples, kiwis, peaches, carrots, celery, tomatoes, melons, and oranges.
Latex Rubber Allergy: Similar to a pollen allergy, people who are allergic to latex rubber may react to bananas, avocados, kiwi, chestnut, and papaya.
The American Academy of Allergy, Asthma & Immunology notes that, "The potential for cross-reactivity can make diagnosing specific allergies somewhat complicated. If you think you have symptoms of a cross-reactivity, an allergist/immunologist can help. An allergist has advanced training and experience to test which allergens are causing your symptoms and prescribe a treatment plan to help you feel better and live better."
Our physicians have a great deal of experience in treating OAS, so if you or someone you know is having symptoms, please contact one of our offices for a consultation.