Perilla Seed Allergy in Children: Cosensitization and Cross-Reactivity with Sesame Seed

Purpose: Perilla seed (PS) is the most common cause of seed-induced anaphylaxis in Korean children, but the reports on PS allergy, including phenotype and cross-reactivity, are rare. The aim of this study is to assess the clinical characteristics of PS allergy and investigate cross-reactivity with sesame seed (SS). Methods:Through a retrospective medical record review, patients with clinical PS allergy were identified in a single tertiary hospital. Clinical characteristics of allergic reaction upon exposure to PS and SS, results of skin prick test (SPT) to PS and SS, and the levels of serum SS-specific immunoglobulin E (SS-sIgE) were investigated. Cross-reactivity between PS and SS was studied using IgE enzyme-linked immunosorbent assay (ELISA) inhibition. Results: The median age of 34 PS-allergic children was 41.5 months (range, 10 months to 12 years), and the proportion of anaphylaxis upon exposure to PS was 29.4% (n =10).The PS SPT was positive in 94.1% (n = 32) with the median wheal size of 6.25 mm. Among PS-allergic children, the percentages of patients with positive symptoms, negative symptoms, and indeterminate symptoms upon exposure to SS were 8.8%, 41.2%, and 50%, respectively. Out of 14 PS-allergic children who were tolerant to SS, positive sensitization to SS was noticed in 78.6% by serum SS-sIgE, and 57.1% by SS SPT. Partial cross-reactivity between PS and SS was identified in IgE ELISA inhibition. Conclusion:This study reported the clinical profiles and SPT results in a relatively large number of PS-allergic children and identified the partial cross-reactivity between PS and SS for the first time.