Correlation of oral allergy syndrome due to plant-derived foods with pollen sensitization in Japan

Background The clinical features of patients with oral allergy syndrome (OAS) due to plant-derived foods related to pollen allergy have been rarely reported in Japan. Objectives To evaluate the characteristics of OAS and to investigate whether pollen sensitizations are correlated with the prevalence of OAS in Japan. Methods We measured specific IgE antibodies against 5 pollens in 622 outpatients (277 males and 345 females; mean age, 37 years) with atopic dermatitis, urticaria, angioedema, and food allergy during a 2-year period. Furthermore, OAS is diagnosed based on anamnesis and positive skin prick test reactions to suspected foods. Results Eighteen of the 436 patients (4.1%) sensitized to pollens were diagnosed as having OAS. Rates of specific IgE antibody–positive responses against Japanese cedar, ragweed, orchard grass, mugwort, and alder pollen were 69.8%, 35.3%, 29.1%, 24.1%, and 19.6%, respectively. The prevalence of OAS showed a significant positive correlation with sensitization to alder ( P P P P P P P Conclusion Sensitization to pollens from species in the Betulaceae family is most strongly implicated in causing OAS in Japan.