Stevens-Johnson syndrome and toxic epidermal necrolysis: a cross-sectional analysis of patients in an integrated allergy repository of a large health care system.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse reactions, carrying an associated mortality ranging from 5% to 40%. Known risk factors for SJS/TEN include HIV infection, female gender, and certain HLA genotypes. Various medications have been described to cause SJS/TEN, with strongest associations with allopurinol, antiepileptics, nonsteroidal antiinflammatory drugs (NSAIDs), sulfa-containing antibiotics, b-lactam antibiotics, quinolones, and nevirapine. SJS/TEN is rare, affecting about 2 persons per million per year, with SJS 3 times more common than TEN. However, much of the epidemiologic data on SJS/ TEN are limited to national and international reporting networks or cohorts after specialist referral or hospitalization. The largest US epidemiologic data identified cases on the basis of International Classification of Diseases, Ninth Revision, Clinical Modification codes. We aimed to determine the prevalence of SJS/TEN among patients in a large health system by searching an electronic allergy repository and to evaluate demographic, allergy, and allergen characteristics of this population.