Anaphylaxis to parenteral thiamine (vitamin B1).

Anaphylaxis as an adverse systemic reaction to thiamine (vitamin B1) has been described in the literature since 1938. Although its precise mechanism is still uncertain, the reaction appears to involve immediate type hypersensitivity and to be exclusively related to parenteral administration. The following case report is a reminder of this reaction to thiamine which may be administered by general practitioners, emergency physicians and internists.