A few minutes after sucking a lozenge for a sore throat a 68-year-old man developed an anaphylactic shock. At a heart rate of 110/min there was no palpable blood pressure. A red confluent exanthem, predominantly of the trunk, was noted. After brief intensive-care treatment the patient was completely well again and diagnostic tests for allergy were performed. The prick test for the 14 individual ingredients of the throat lozenge produced massive reddening and urticaria on the test arm with carbowax, a polyethylene glycol which serves as a vehicle in the remedy and does not have to be listed. Later there were an urge to cough and urticaria all over the trunk. There was no systemic reaction. Neither specific IgE antibodies nor any complement-consuming reaction could be demonstrated. Thus the precipitating mechanism remains unexplained.