You Dropped the Bomb on Me: A Case Series of Carbon Tetrachloride Toxicity

Carbon tetrachloride (CCl₄) is a halogenated hydrocarbon that is a colorless, clear liquid with a sweetish, ether-like, nonirritant odor. It was previously used in dry cleaning agents, refrigerants, and fire extinguishers. CCl₄ toxicity is rarely observed. Two patients with acute hepatitis following exposure to a CCl₄-containing antique fire extinguisher are presented. A son (patient 1) and father (patient 2) were admitted to the hospital with acute, unexplained elevated transaminases. After extensive questioning, they reported recent exposure to a large amount of CCl₄ when an antique firebomb shattered in their home. Both patients cleaned the debris without personal protective equipment and slept in the contaminated area. The patients presented to the emergency department (ED) at varying times between 24 and 72 hours after CCl₄ exposure. Both patients received intravenous N-acetylcysteine (NAC); patient 1 also received oral cimetidine. Both recovered uneventfully without sequelae. Extensive workup for other causes of elevated transaminases was unremarkable. Serum analyses for CCl₄ were also unremarkable due to the delay between exposure and hospital presentation. CCl₄ is a potent hepatotoxin. CCl₄ metabolism via cytochrome CYP2E1 produces its toxic metabolite, the trichloromethyl radical. This radical covalently binds to hepatocyte macromolecules and causes lipid peroxidation and oxidative damage with ensuing centrilobular necrosis. Treatment is not well established, but NAC is likely beneficial via glutathione repletion and antioxidant effects. Cimetidine blocks cytochrome P450 and, thus, metabolite formation. Cimetidine may also promote the stimulation of regenerative processes acting on DNA synthesis. CCl₄ toxicity is rare and infrequently reported in current literature but should be maintained in the differential of acute hepatitis. Two patients presenting nearly identically - at two different ages but from the same household - offered a clue to this enigmatic diagnosis.