Diagnosing Pollen-food Allergy Syndrome Allergologically in a Patient with Suspected Eosinophilic Gastroenteritis

Pollen-food allergy syndrome (PFAS) consists of type I allergy to pollen and multiple food items that are cross-reactive to the pollen. PFAS typically occurs in the oral cavity and can co-occur with eosinophilic esophagitis. However, it is infrequently reported to present with symptoms of eosinophilic gastroenteritis (EGE), such as abdominal pain and eosinophilic infiltration of the gastrointestinal tract. We herein report a patient with a condition initially suspected of being EGE based on symptoms and pathological findings that was later diagnosed as PFAS associated with birch pollen. PFAS should be considered as a differential diagnosis in patients with EGE-like symptoms.