Background Stevens-Johnson syndrome (SJS) is an immune-mediated hypersensitivity complex, most often triggered by drugs (Foster, 2011). It is characterized by a prodrome of malaise and fever, followed by a rapid onset of erythematous or purpuric macules and plaques. Skin lesions progress to epidermal necrosis and desquamation. Mucous membranes are affected in 92–100% of patients, usually at two or more distinct sites (High & Nirken, 2012). The syndrome was first described in 1922, when American pediatricians Albert Mason Stevens and Frank Chambliss Johnson reported cases of 2 boys aged 7 and 8 years with "an extraordinary generalized rash with continuous fever, inflamed buccal mucosa and severe purulent conjunctivitis". . Both cases were misdiagnosed by GPs as haemorrhagic measles (Foster, 2011). Erythema multiforme (EM), originally described by von Hebra in 1866, was part of the differential diagnosis in both cases but was excluded due to the "character of skin lesions, absence of subjective symptoms, prolonged high fever and terminal crusting heavy." Despite the presence of leukopenia in both cases, Stevens and Johnson in their initial report suspected an infectious disease of unknown etiology as the cause (Hazin, Ibrahimi, Hazin & Kimyai-Asadi, 2008). In 1950, Thomas divided EM into 2 categories: erythema multiforme minor and erythema multiforme major. Since 1983, erythema multiforme major and Stevens-Johnson syndrome have been considered synonymous (Foster, 2011). In the 1990s, however, Bastuji and Roujeau each proposed that erythema multiforme major and Stevens-Johnson syndrome are two distinct disorders (Roujeau, 1997). . They suggested that the diagnosis of erythema... half of the paper... of the mucous membranes, vaginal synechiae, nail dystrophy, and diffuse hair loss (Habif, 2004). Bibliography Foster, C.S. (2011, September 23). Steven-Johnson syndrome. Retrieved from http://www.emedicine.medscape.com/article/1197450 Hazin, R., Ibrahimi, O. A., Hazin, M. I., & Kimyai-Asadi, A. (2008). Steven-Johnson syndrome: pathogenesis, diagnosis and management. Annals of Medicine, 40(2), 129-138.High, W.A., Nirken, M.H. (2012). Steven-Johnson syndrome and toxic epidermal necrolysis: management, prognosis and long-term sequelae. Retrieved from http://www.uptodate.com/contents/steven-johnson-syndrome-and-tossici-epidermal-necrolysisMcCance, K. L., Huether, S. E., Brashers, V. L., & Rote, N. S. (2010). Pathophysiology: the biological bases of diseases in adults and children. (6th ed., pp. 1644-1645). Maryland Heights, VA: Mosby.