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Management and prognosis of oral allergy syndrome (pollen-food allergy syndrome)

Anna Nowak-Węgrzyn, MD
Section Editor
Scott H Sicherer, MD, FAAAAI
Deputy Editor
Anna M Feldweg, MD


The oral allergy syndrome (OAS) or pollen-food allergy syndrome (PFAS) describes allergic reactions that typically occur upon ingestion of certain uncooked fruits, nuts, vegetables, or spices in pollen-sensitized individuals [1,2]. The causative allergens in these plant foods are homologous to pollen allergens. The symptoms result from contact urticaria of the mucosal surface that touches the food, and symptoms are usually limited to the mouth and throat. Symptoms appear quickly after eating raw forms of the food, because the responsible allergens are rapidly inactivated by cooking and digestion, although this is not always true. Systemic reactions are observed in 2 to 10 percent of patients, and reactions to cooked plant foods (including roasted nuts) are possible.

This topic review presents the management and prognosis of patients with PFAS. The clinical manifestations, diagnosis, and pathogenesis of PFAS are reviewed separately. (See "Clinical manifestations and diagnosis of oral allergy syndrome (pollen-food allergy syndrome)" and "Pathogenesis of oral allergy syndrome (pollen-food allergy syndrome)".)


In this topic review, the term "oral allergy syndrome" (OAS) is used to describe reactions limited to the oropharynx that are caused by food proteins that are homologous to pollen proteins. "Pollen-food allergy syndrome" (PFAS) or "pollen-associated food allergy syndrome" is a broader term that encompasses both oropharyngeal and systemic symptoms and is the preferred term for the spectrum of reactions caused by allergens in plant foods that are homologous to pollen allergens.


The approach presented in this topic review is based upon the author's practice experience, because there are limited guidelines for the management of pollen-food allergy syndrome (PFAS) and clinicians vary considerably in their practices [1,3-6]. A questionnaire mailed to 226 randomly-selected allergy specialists across the United States illustrated the variability in approach to this disorder [3]. Of the 122 allergists who responded, 53 percent recommended complete avoidance of causal foods to all patients, whereas 9 percent did not advocate any restrictions. Sixty-six percent of allergists prescribed epinephrine for oral allergy syndrome (OAS) on a case-by-case basis, 30 percent never prescribed it, and 3 percent always did. (See 'Indications for epinephrine' below.)

Avoidance — Dietary avoidance of the offending plant food(s), in the form in which it causes symptoms, is the most common approach to management. However, strict avoidance may not be uniformly necessary if symptoms are mild. Additionally, patients may continue to eat forms of the foods that do not cause symptoms. Cooked, processed, and sometimes frozen forms of the foods typically do not cause symptoms of PFAS. The purpose of avoidance is the prevention of future reactions. However, there are no studies reporting the impact of avoidance on the natural history of the condition. (See 'Prognosis' below.)


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Literature review current through: Sep 2016. | This topic last updated: Jan 4, 2016.
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