Oral allergy syndrome (pollen-food allergy syndrome).

Oral allergy syndrome (OAS) or pollen-food allergy syndrome (PFS) is a hypersensitivity reaction to plant-based foods, manifesting most commonly with pruritus of the lips, tongue, and mouth. Unlike simple food allergy, OAS requires prior sensitization to a cross-reacting inhalant allergen rather than direct sensitization to a specific food protein. In this review, we summarize the clinical features and pathophysiology of OAS and provide an overview of known pollen-food associations.