Chemical hepatitis associated with occupational exposure to halothane in a research laboratory.

We report a case of clinical hepatitis associated with occupational exposure to halothane in a research laboratory. A biochemist who for 3 y repeatedly used halothane for sedation and euthanization of rats suffered recurrent episodes of epigastric discomfort, culminating in an episode of malaise, anorexia, jaundice and elevated liver associated enzymes that promptly resolved after removal from exposure to halothane. Serologic testing for viral sources and risk factors for non-infectious hepatitis were negative. Halothane-induced hepatitis has been documented as an idiosyncratic reaction among anesthetized patients and has been reported once in operating room personnel. The mechanism for halothane-induced hepatitis is proposed to be a hypersensitivity reaction to liver neo-antigens produced by the halothane metabolite 2-chloro-1, 1, 1-trifluoroethane.