Researchers conducted this study to review OAS.

The researchers searched several medical literature databases with the following keywords: “oral allergy syndrome,” “OAS,” “pollen-food allergy syndrome,” “PFAS,” “allergy,” “diagnosis,” “treatment.”

OAS, also called “pollen-food allergy syndrome,” is a type of food allergy brought about by flavors, nuts, raw fruit, and vegetables. The most well-known symptoms are the mouth, and throat itching, which starts after food is placed in the mouth, which continues just after the food is swallowed. OAS’s frequency with a pollen allergy has been reported as 5–8%; 1–2% of patients with OAS with pollen allergy show extreme responses, e.g., anaphylaxis. Birch tree pollen, ragweed pollen, and grass pollen hypersensitivity cause the symptoms. OAS’s diagnosis is confirmed by a positive history and positive skin-prick test result triggered by the food’s fresh extract. Oral challenge result is ordinarily positive with the raw food and negative with the similar cooked food.

The study concluded that patients with grass allergy might respond to peaches, oranges, celery, tomatoes, and melons. Patients with ragweed allergy may show OAS symptoms with melon, cucumber, banana, and zucchini. Physicians should be aware of OAS and know the appropriate treatment.