Urticarial and anaphylactoid reactions following ethanol intake

Ingestion of ethyl alcohol may be associated with a number of adverse reactions. Apart from toxicological effects, intolerance syndromes occur, which are caused by genetic or acquired defects in alcohol metabolism and are manifest clinically as flushing. In addition to these abnormalities, rare cases of generalized urticaria and anaphylactoid reactions after ingestion of ethyl alcohol have been reported, the pathogenesis of which is still a matter of debate. We describe three patients who presented with recurrent generalized urticaria, which developed within minutes of consumption of small amounts of ethyl alcohol. Common causes of chronic recurrent urticaria were excluded by case history, physical examination and laboratory investigations, and by comprehensive allergy testing. All patients produce positive prick tests with acetic acid, and developed urticaria after oral challenge with small amounts of highly purified ethyl alcohol. The symptoms are most probably caused by an intolerance to ethyl alcohol or its metabolites, whereas an allergy sensu strictu seems unlikely.