BACKGROUND Severe cutaneous adverse reactions (SCARs) include Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS). SJS and TEN (SJS/TEN) and DRESS are thought to be different diseases; however, they share some clinical and laboratory features. Although SCORTEN serves as an excellent prognostic marker for SJS/TEN, there is still a need for development of other prognostic markers for SCARs.

METHODS The study population consisted of 88 SCAR patients. Clinical characteristics and clinical manifestations were compared between SJS/TEN and DRESS. Risk factor analyses for prolonged hospitalization were performed.

RESULTS Of the 88 patients, 41 were SJS/TEN and 47 were DRESS. Mortality rates of TEN and DRESS were 9.8 and 2.1%, respectively. Allopurinol and carbamazepine were the most common causes of both SJS/TEN and DRESS (34.7 and 62.9%, respectively). Some of the systemic presentations, such as fever and laboratory abnormalities were common in both phenotypes. Thrombocytopenia tended to be related to prolonged hospitalization (longer than 3 weeks) in SJS/TEN (odds ratio, OR = 5.1, 95% confidence interval, CI 0.8-31.8, p = 0.076). In DRESS patients, leukocytosis at presentation (OR 4.8, 95% CI 1.1-20.3, p = 0.03) was related to prolonged hospitalization.

CONCLUSIONS Clinical features of SCARs in a tertiary hospital in Korea were similar to those reported previously. SJS/TEN and DRESS shared some clinical and laboratory features. Thrombocytopenia for SJS/TEN and leukocytosis at presentation for DRESS may be useful prognostic markers for prolonged hospitalization.