Have you heard of oral allergy syndrome? A type of food allergy pollen that results in swelling, tingling and itching in the throat and mouth.
The American Academy of Allergy, Asthma and Immunology says oral allergy syndrome (OAS) is a reaction to the proteins found in some fruits and vegetables that are very similar to those found in pollen. These proteins can confuse the immune system and cause an allergic reaction or make existing symptoms worse. This means that should you have a pollen allergy to grass, weeds or trees, you may have an allergic reaction to foods containing similar proteins to those found in the pollen. The organisation also says some people report symptoms with only one food and others with many different fruits and vegetables. Some people report that only certain varieties of the fruit cause symptoms, for example, specific apple varieties.
Also read our article on food allergies.
spot the symptoms
Dr Marinda McDonald, an allergy specialist at the Allergy Clinic, says: “This allergic phenomenon does not generally progress to give a more serious reaction. There are, however, some cases where it does cause a runny nose, itchy eyes and, very rarely, anaphylaxis (a severe generalised allergic reaction).” Other signs of existing OAS include itching mouth, palate, ears and throat, tingling in the mouth, palate or throat, watering eyes and sneezing, swelling of the lips, mouth, tongue, face or throat (very rare). Some body parts may even itch when handling the raw fruit or vegetable, existing eczema might flare up, and there may be a sensation of the throat tightening.
managing oral allergy syndrome
Reactions to the food normally occur in its raw (uncooked) state. Once the food is cooked or processed, it can usually be eaten. Peeling the food may also help remove the offending allergen. Minimal heating, treating the raw fruit for a brief period in a microwave while retaining some crispness, may also work for some people. Dr McDonald says: “A healthcare professional who has knowledge of allergies can evaluate the risk of the reaction involved. A good clinical history by an experienced doctor is also advised.” Antihistamines might offer some relief, explains Dr McDonald, but in severe cases, you should seek medical help fast. “OAS is a lifelong burden so it’s probably best to simply avoid foods that cause your OAS.”
Find out more about OAS by watching this video by a healthcare expert.
the main offenders
If you are allergic to the following, you may develop or have oral allergy syndrome when eating these fruits and vegetables:
- Birch pollen – Apples, pears, plums, kiwis, apricots, cherries, peaches, almonds, raw potato, hazelnuts, carrots, celery, parsley, caraway, fennel, coriander, aniseed, soybeans, or peanuts.
- Mugwort pollen – celery, apple, peanut, kiwi fruit, carrot, parsley and spices (fennel, coriander, aniseed, cumin)
- Ragweed pollen – melons (watermelon, cantaloupe, honeydew) banana, zucchini, cucumber and squash.
- Latex – avocado, kiwi fruit, chestnut, papaya and banana.
Other common OAS triggers include nectarines, strawberries, spinach, tomato, camomile tea and honey.
*Note: In South Africa, other pollens can cause a reaction.
