Atopy and anaphylactic reactions to suxamethonium.

Muscle relaxants are widely used for general anesthesia and may be responsible for IgE-dependent anaphylactic reactions (AR). A controversial issue in the field of drug allergy is whether ARs are more frequent or severe in atopic subjects. Thus, we performed a case-control study comparing the distribution of various clinical and biologic signs of atopy. The case group included 32 patients with a history of AR to suxamethonium, the most commonly used muscle relaxant. The control group included 128 subjects, matched to the case group according to age, gender, and socioeconomic status. The case group consisted mainly of young and middle-aged women. Distribution of symptoms suggestive of atopy and of skin tests and specific IgE to common aeroallergens was similar in both groups. In contrast, total serum IgE level was much higher in the case group, suggesting the presence of specific IgE against suxamethonium or other drugs. Thus, despite previous studies in the literature, atopy is not a risk factor for the occurrence of anaphylactic reactions to muscle relaxants. As AR to suxamethonium is a pure model of an IgE-dependent drug allergy, our data do not support a relationship between atopy and allergic drug reactions.