Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS): 11 years retrospective study in Thailand.

BACKGROUND: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but life-threatening adverse drug reaction. Several criteria have been established to aid the diagnosis. However, patients with DRESS remained underdiagnosis and undertreatment. METHODS: Medical records of hospitalized patients at the King Chulalongkorn Memorial Hospital from January 2004-December 2014 due to DRESS were enrolled retrospectively using RegiSCAR diagnostic criteria. RESULTS: A total of 52 patients were included. Thirty-seven patients (71.2%) were female. The four most common causative agents were phenytoin (23.1%), nevirapine (17.3%), allopurinol (15.4%), and cotrimoxazole (13.5%). The overall prevalence was 9.63 cases per 100,000 inpatients. Median onset time (IQR) was 16 (9-27) days. Allopurinol was associated with longer onset time than others (p = 0.014). CLINICAL PRESENTATION: skin rash 100%, fever 78.8%, and lymphadenopathy 50%. The majority (84.6%) had single internal organ involvement. The most common internal organ involvement was liver (94.2%). Allopurinol was associated with higher incidence of renal involvement (p = 0.01). Up to 60% of patients had eosinophilia. Allopurinol was associated with higher eosinophilia (p = 0.003). A half of patients received systemic corticosteroids. Two mortality cases were reported (omeprazole-fulminant hepatitis and phenytoin-nosocomial infection). CONCLUSIONS: DRESS is associated with severe morbidity and mortality. Phenytoin, nevirapine, allopurinol, and cotrimoxazole were the major causes. Allopurinol-induced DRESS had the longest onset time, and was associated with higher eosinophilia and incidence of renal involvement. Raising awareness among both health care providers and public for early detection and withdrawal of the causative agent is critical to save life and reduce morbidity.