[Case of acute generalized exanthematous pustulosis caused by Kerorin].

A 78-year-old woman visited a local clinic because of cough and fever, and was prescribed levofloxacin, carbocisteine, and cold medicine (salicylamide, acetaminophen, anhydrous caffeine, promethazine methylene disalicylate). The following day, erythema appeared on the trunk, and spread. Multiple pustules independent of hair follicles developed on the erythema mainly in the skin folds. Histopathological examination revealed subcorneal pustular dermatosis. The clinical course and characteristics of the rashes led to a diagnosis of acute generalized exanthematous pustulosis (AGEP). Although the administration on levofloxacin, carbocisteine, and cold medicine were discontinued, the rashes recurred. We reviewed the patient's history, and found that she had a history of taking the over-the-counter drug Kerorin, and had taken a dose of Kerorin on the day before the first examination and before the recurrence. The ingestion of Kerorin was regarded as an incidental oral administration test, which was positive. Thus, oral administration tests with Kerorin and its ingredients acetylsalicylic acid and anhydrous caffeine were positive, leading to a diagnosis of AGEP caused by Kerorin.