A Report of Two Cases of Anaphylaxis Caused By Perilla Seed in Children

Perilla (Perilla frutescens) seed, also known as wild sesame seed is one of the popular spices in Asia but serious allergic reactions to perilla seed have been rarely reported. Herein we report two cases of anaphylaxis caused by perilla seed in children. A 25-month-old boy presented to the outpatient clinic at Ajou University Hospital with previous experiences of urticaria and facial angioedema immediately after ingestion of soup containing perilla seed powder at ages of 13 months and 21 months. He had past history of asthma and previous experience of lip angioedema after ingesting kiwi for the first time at 9 months old. As the specific IgE (sIgE) test to perilla seed is not commercially available, the sIgE to sesame seed, which belongs to Lamiales like perilla, was measured instead. The sIgE level to sesame seed was 2.98 kU_A/L at 25 months, and was 3.37 kU_A/L at 4 years of age. The sIgE level to kiwi was 1.42 kU_A/L and multiple allergosorbent test chemiluminescent assay (MAST CLA) revealed no remarkable sensitization to inhalant allergens. To confirm the causal relationship, an open oral food challenge (OFC) with perilla seed powder was performed when he was 4 years old. Immediately after the contact of extremely small amount of perilla seed powder around his lips, he developed urticaria, facial angioedema, cough and rhinorrhea. He was treated with intramuscular epinephrine, after which his symptoms resolved completely. The second patient, a 5-year-old boy, presented to the outpatient clinic with a previous history of urticaria, lip angioedema, pruritis of tongue and hoarseness immediately after ingestion of seaweed soup containing perilla seed a few months before. He had past history of asthma, allergic rhinitis and atopic dermatitis and was previously diagnosed as allergic to egg white and peanut. He also had oral allergy syndrome to kiwi fruit. Moderate sensitization to alder, birch and white oak was noted in MAST CLA and sIgE levels to sesame seed, egg white, peanut and kiwi were 1.01 kU_A/L, 1.47 kU_A/L, 2.82 kU_A/L and 3.19 kU_A/L, respectively. The OFC test with perilla seed was not performed in this patient because his initial symptoms were compatible with anaphylaxis. For the etiologic confirmation, Enzyme-Linked ImmunoSorbent Assay (ELISA) and IgE western blot with crude extract of perilla seed produced in our own laboratory are in progress for both patients. To the best of our knowledge, this is the first report of anaphylaxis caused by perilla seed in children.