[A case of anaphylaxis induced by gelatin-contained gel capsule cold medicine].

We report here a 20-year old woman who referred to our clinic for identify the responsible antigen of anaphylaxis. Five days before the reaction, she had a cold and had taken a gel capsule cold medicine, Stona IB Gel®. On the day of the reaction, she took a dose of Stona IB Gel® after eating yogurt. Five minutes after oral administration, she developed a heat sensation and pruritus on her neck, with flushing, abdominal pains, breathing difficulties, and syncope. The specific IgE antibodies measured by ImmunoCAP® were all negative except for gelatin. Prick-prick skin testing revealed positive responses to Stona IB Gel®, gelatin KS and gelatin RP600, of which the latter two were included in the Stona IB Gel® capsule. From these test results, she was diagnosed with anaphylaxis due to gelatin, and to date she has had no further allergic symptoms since avoiding foods containing gelatin. In infancy she had received four vaccinations against diphtheria, pertussis and tetanus, which contained gelatin as a stabilizer. However, she had not developed allergic symptoms until this time. We hypothesize that she might be sensitized to gelatin by taking Stona IB Gel® during the preceding 4 days. This is the first case of anaphylaxis from the ingestion of an oral medication containing gelatin in Japan. Allergic reactions to gelatin are comparatively rare, but according to the past reports, the reactions were severe. Since many kinds of foods, cosmetics, pharmaceutical products, and medication contain gelatin, it is important to be aware of gelatin allergy.