Evaluation of the incidence of systemic symptoms in PR-10-related pollen-food allergy syndrome in Western Japan.

Background: Pollen food allergy syndrome (PFAS) primarily presents as oral allergy syndrome (OAS) with occasional systemic symptoms. Few studies have examined the systemic symptoms of PR-10-related PFAS, which are common among pediatric patients in Japan.

Methods: Two surveys were conducted to investigate the possibility of more severe patients in medical institutions and misdiagnoses among school children: one for patients diagnosed with PR-10-related PFAS at medical institutions and another for elementary and junior high school children whose parents completed an online questionnaire. We examined allergenic foods/symptoms, incidence of OAS, and systemic symptoms in PR-10-related PFAS patients allergic to Rosaceae fruits/soybeans.

Results: Among 221 patients with PR-10-related PFAS at medical institutions, 205 and 86 developed allergic symptoms to Rosaceae fruits and soybeans, respectively. The incidence of systemic symptoms was significantly higher in the soybean group (43/86, 50.0%) than in the Rosaceae fruits group (43/205, 21.0%) (p < .001). Among the 29,906 school children, 3309 (11.1%) responded; 202 were children with PR-10-related PFAS, 194 and 29 developed allergic symptoms to Rosaceae fruits and soybeans, respectively. The incidence of systemic symptoms was higher in the soybean group (12/29, 41.4%) than in the Rosaceae fruits group (46/194, 23.7%), although not significantly (p = .067).

Conclusion: Two surveys were conducted targeting patients with confirmed diagnoses and general students. The incidence of systemic symptoms associated with PR-10-related PFAS was similar at 20% for Rosaceae fruits and 40%-50% for soybeans in both surveys. Attention should be given to the potential for systemic symptoms in patients with PR-10-related PFAS.