A Comparative Clinical Study of Toxic Epidermal Necrolysis and Stevens-Johnson Syndrom Young Gull Kim, M.D., Kwang Hyun Cho, M.D., Jin Ho Chung, M.D. Department of Dermatology, Seoul National University, College of Medicine, Seoul, Korea. We reviewed the clinical records of the patients with toxic epiderraal necrolysis and Stevens-Johnson syndrome who had been treated Seoul National University Hospital from May, 1985 to March, 1991. Twelve patients with toxic epidermal necrolysis(8 males, 4 females) were included. Their mean age was 39 years and the mean hospital days of the surviving patients were 22 days. Eleven patients had had the history of ingestion of more than two drugs before flaring up of the disease. Non-steroidal artiinflammatory agent was most frequently suspected as a culprit drug. Eight patients showed abnormal liver function and five patients showed abnormal renal function. Three of ten patients who were tested with serum phosphours level showed hypophosphatemia. Five patients(39%) expired with the cause of death, sepsis for three patients, and pseudomembrarieous colitis and fulminant hepatitis for the others respectively. Three of them were patients over 60 years of age and the mean age of all the expired patients was 53 years. Ophthalmologic sequalae were found in 5 of 7 improved patients. The mean age and the mean hospital days of eight patients with Stevens-Johnson syndrome(4 males, 4 femalse) were 27 years and 14 days. Seven of eight patients had the history of drug ingestion. Laboratory findings were normal except for leukocytosis in two of them and abnormal liver function in three of them. All recovered without any significant complication. (Kor J Darmatol 29(5) : 602-609, 1991)