Oral Allergy Syndrome
Oral allergy syndrome can be seen in patients with pollen allergy who experience mouth and throat itching, typically when eating fresh fruit and vegetables such as apples, melons, celery and carrots, but also with peanuts and tree nuts such as hazelnut. Most symptoms are felt in the mouth with itching, but there may also be gastrointestinal symptoms such as nausea, vomiting, diarrhea and abdominal pain. Some patients describe symptoms similar to pollen exposure such as itching eyes and nose, congestion and runny nose. Rarely patients develop throat swelling, hives or anaphylaxis.
Most often oral allergy syndrome begins with a pollen allergy such as birch, ragweed or grass. Oral symptoms are seen among 70% of birch sensitive patients and 20% of grass sensitive patients. An allergy to particular foods may follow.
What causes oral allergy syndrome?
Compounds in certain foods are similar to compounds on the surface of pollen grains. Acting as a local allergen, these compounds can trigger itching in the mouth and throat among sensitized people. Many of these compounds are concentrated near the skin of fruits, so a peeled apple may cause fewer symptoms than the unpeeled fruit.
Many food allergens degrade with cooking and digestion so apple sauce may cause fewer symptoms than fresh apples; carrots in a soup may cause fewer symptoms than raw carrots. People on stomach acid blocking medications may experience more gastrointestinal symptoms, as these medications impair gastric digestion.
Pollen and related foods that can cause symptoms:
- Birch — Hazelnut, carrot, kiwi, parsley, almond, soybean, celery, potato, orange, peanut, apple family (i.e. peaches, plums, nectarines)
- Ragweed — Milk, melons, banana, lettuce, mint, cucumber, zucchini, chamomile tea, egg, white potato
- Grasses — Legumes (peas, beans, soybeans, all beans such as kidney, navy, garbanzo, etc.), grains, apple, carrot, celery, orange, tomato, white potato, zucchini
- Cedar — Apple, cherry, bell peppers, kiwi, paprika, tomato
- Sage, Mugwort — Celery, coriander, potato, tomato, carrot, fennel, peppers, sunflower, parsley, broccoli, cabbage, cauliflower, garlic, onion, caraway
- Marigold — Milk
- Cedar, juniper — Beef, yeast
- Elm — Milk, mint
- Oak — Egg, chestnut, apple
- Pecan, hickory — Corn, banana, apple
- Pigweed, amaranth — Pork, black pepper
- Ivy Ciliata (poison ivy) — Wheat, pork, black pepper
- Mesquite — Cane sugar, orange
- Cottonwood — Lettuce
Other allergens and related foods that can cause symptoms
- Dust — Peanut, snails, oysters, clams, scallops
- Latex — Banana, avocado, kiwi, chestnut, potato, cinnamon, plantain, tomato, walnut
- Candida — Cheeses, mushrooms, vinegar, fermented moldy foods
Oral allergy symptoms are seen more often during peak allergy season:
- Spring for birch
- Summer for grass
- Fall for ragweed
Treatment can include:
- Limit the amount and frequency of foods that cause symptoms, particularly during peak allergy seasons.
- Treat the underlying pollen and food allergy with sublingual immunotherapy.
- Use oral antihistamines as needed to control temporary symptoms.