Oral allergy syndrome (OAS) is when plant proteins from pollen and fruits or vegetables react with each other. This occurs when a child or adult with a pollen allergy eats a raw fresh fruit or vegetable. The immune system sees the plant protein as pollen which causes an allergic reaction. Peeling the skin or cooking the food will often change the protein enough to prevent this.
OAS is most common in people with asthma or hay fever from tree pollen. It seems to affect adults more than children. Not all who have these allergies will get OAS.
Itchy mouth or ears
Swelling of the lips, mouth, tongue and throat
Symptoms most often go away once you remove the food from your diet.
Birch pollen: apple, almond, apricots, carrot, celery, cherry, hazelnut, kiwi, nectarines, peach, pear, plum, prunes, fennel, parsley, coriander, parsnips, hazelnuts, and walnuts
Grass pollen: celery, melons, oranges, peaches, tomato
Ragweed pollen: banana, cucumber, melons, sunflower seeds, zucchini, dandelions, chamomile tea
Alder pollen: celery, pears, apples, almonds, cherries, hazelnuts, peaches, parsley
Latex: bananas, avocado, kiwi, chestnuts, papaya
Mugwort: celery, pears, apples, almonds, cherries, hazelnuts, peaches, parsley, coriander, sunflower, peppers
How It Is Diagnosed
Your doctor will review your health history. In some cases, you may need a skin test or oral food test. Some reactions can be severe. Ask your doctor if you need an EpiPen®.