[Hypersensitivity syndrome caused by allopurinol. A case of massive hepatic necrosis]

Adverse drug reactions have a wide variety of clinical manifestations mainly related to the affected organ. The skin is one of the most common organs involved due to the visibility of the lesions to the observer. These untoward drug cutaneous responses may mimic any known dermatosis, and may be a clue to a serious systemic disease. We present the case of a 72 year-old woman with erythema multiforme, liver and renal failure due to a unknown dosage of allopurinol self-medication for two weeks. The clinical course was characterized by a Stevens-Johnson syndrome and severe drug-induced liver disease with massive hepatic necrosis corroborated by a transjugular liver biopsy; finally she died of gastrointestinal bleeding. Consent for a postmortem study was not obtained. The clinical course as well as the cutaneous, renal and hepatic drug-related complications corresponds to an allopurinol hypersensitivity syndrome. The relevance of this case was the extension of the liver damage apparently due to the allopurinol, which is an infrequent hepatotoxic complication. In some cases, like the present case, it can be a serious and fatal complication.