2.1 Case Inclusions, Data Collection and Validation
Inpatients referred to the Department of Dermatology, Singapore General Hospital between 2009 and 2017 with a diagnosis of DRESS were retrospectively screened. Clinical and epidemiological data including demographics, photographs, investigations, histology, clinical course, treatments, outcomes were summarized from medical records.
These screened cases were re-validated by a team of dermatologists (HYL, YWY, KC) according to the standardised RegiSCAR DRESS scoring system.18 Ambiguities and differences during case validation were resolved via consensus. Briefly, the RegiSCAR DRESS scoring system is a standardized scoring system based on the clinical features and investigations with a final score that ranges from -4 to 9. Cases were designated as not DRESS if score is <2, possible case if score is 2-3, probable case if score is 4-5, and definite case if final score is >5.18Cases of probable or definite cases of DRESS (Final RegiSCAR score of 4 or more) were included for analysis. DRESS flares were defined as skin eruption not attributable to other skin disorders.