Surveillance of pollen-food allergy syndrome in elementary and junior high school children in Saitama, Japan

Background: Because few studies have epidemiologically evaluated pollen-food allergy syndrome (PFAS), relevant information about this disease is limited in children. Objective: We wanted to clarify the epidemiological details of PFAS by creating a questionnaire which enables to distinguish class 2 food allergy from that of class 1. Methods: We conducted a questionnaire survey for schoolchildren attending to public elementary and junior high schools. In this questionnaire, we asked about both the allergy to fruits and/or vegetables and allergic rhinitis (AR). PFAS was, then, defined as allergy for fruits and/or vegetable which occurred after the symptoms of AR appeared. Results: A total of 2,346 children (median age, 10.6 +/- 2.5 years; 1,157 boys) were evaluated. The prevalence of PFAS was 6.9% among subjects. The mean ages in the onset of AR and PFAS were 4.59 +/- 2.76 and 7.38 +/- 3.17 years old, respectively. Various kinds of foods were shown to be causative, among which kiwifruits were the commonest. As high as approximately 30% of children with PFAS experienced systemic symptoms including cutaneous (21.8%) and respiratory symptoms (9.6%). Anaphylaxis was diagnosed in 5.8% children. Conclusion: Our results indicated that the prevalence of PFAS was getting higher and the mean age of onset was getting lower. These may be attributed to the increasing number of patients with AR and also to the lower age of onset of AR. We have to be careful to not only local but also systemic symptoms when examining children with PFAS.