RegiSCAR DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms) Validation Scoring System and Japanese Consensus Group Criteria for Atypical Drug-Induced Hypersensitivity Syndrome (DiHS): A Comparative Analysis

Context: Drug reaction with eosinphilia and systemic symptoms (DRESS) and drug-induced hypersensitivity syndrome (DiHS) represent the same spectrum of a drug reaction. Aims: To compare the clinical profile of patients diagnosed as definite/probable DRESS by the Registry of Severe Cutaneous Adverse Reaction (RegiSCAR) scoring system and as atypical DiHS by Japanese consensus group criteria. Settings and Design: We did a retrospective study in a tertiary referral center. Materials and Methods: We included patients who satisfied the criteria for definite/probable DRESS and/or atypical DiHS and who received inpatient care in our department from January 2011 to December 2018. We compared the clinical and laboratory findings in patients diagnosed by the two criteria. Statistical Analysis: Pearson Chi-square test was used to compare the proportion of patients with severe reactions diagnosed by the RegiSCAR DRESS validation scoring system and the Japanese consensus group criteria. Results: Among the 390 case records reviewed, 138 patients could be classified as definite/probable DRESS and/or atypical DiHS. Japanese criteria did not diagnose atypical DiHS in 88/137 (64.2%) patients with definite/probable DRESS. RegiSCAR scoring system made a diagnosis of definite/probable DRESS in 49/50 (98%) patients with atypical DiHS. A total of 58/138 (42%) patients had a severe reaction. RegiSCAR scoring system diagnosed 57/58 (98.3%) patients with severe reaction as definite/probable DRESS. A total of 32/58 (55.2%) patients with severe reactions were diagnosed as atypical DiHS. The difference was statistically significant (<0.001). Conclusion: Japanese criteria for atypical DiHS showed reduced sensitivity to diagnose definite/probable DRESS, and this included more than 40% of patients with severe DRESS.