The oral allergy syndrome (OAS), also referred to as the pollen-food allergy syndrome,1 is a unique form of food allergy characterized by a localized reaction of the mouth and throat that occurs when affected individuals eat certain fresh fruits and vegetables.2 Patients with allergy to ragweed pollen will also often have allergies to melons (watermelon, cantaloupe, and honeydew) and bananas. Individuals with OAS experience contact urticaria (itching and hives) that is confined almost exclusively to the mouth and throat upon ingestion of the triggering food. This condition only rarely affects other target organs.2 Characteristic symptoms of OAS include itching of the lips, palate, tongue, and throat.2 OAS is a self-limiting condition with symptoms that occur immediately on contact with foods and typically resolves rapidly. It is important to differentiate these symptoms from systemic and life-threatening allergic throat constricting reactions that can occur during anaphylaxis. It is interesting to note that individuals with OAS to certain food groups frequently suffer from allergy to related nonfood allergens. Allergy to certain nonfood allergens (such as pollens) appears to predispose individuals for the development of associated food allergy.2
1. Sampson HA. Food Allergy-Accurately Identifying Clinical Reactivity. Allergy. 2005; 60(Suppl 79):19-24. PubMed 15842229
2. American Academy of Allergy, Asthma, and Immunology. The Allergy Report. Milwaukee, Wis: AAAAI; 2000.