"Drug Reaction with Eosinophilia and Systemic Symptoms" (DRESS): Long-term Outcomes Based on Severity - A Cohort Study.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe drug-induced reaction characterized by exanthema, eosinophilia and organ involvement. Patients reported sequelae comprising skin or organ alterations and autoimmune diseases. We investigated long-term complications of patients included in the German Registry of severe skin reactions between 2003 and 2023 with a definite or probable diagnosis of DRESS using a follow-up questionnaire. Cases were classified by severity (mild, moderate-to-severe) employing 2 scores (drug-induced liver injury [DILI] and acute kidney injury [AKI]). In total, 36/61 questionnaires (59%) were analysed revealing an equal distribution: 18 mild and 18 moderate-to-severe cases. All patients experienced long-term complications. Skin disorders occurred in 81%, mucosal problems in 31% and hair/nail complications in 43%. Severity groups were equally affected, whereas laboratory abnormalities appeared more often in moderate-to-severe cases. Haematological abnormalities were most frequently observed (94%), followed by elevated liver enzymes (88%) and impaired renal function parameters (31%). Alterations of HbA1c occurred in 16% and abnormal thyroid function in 19%, including 2 cases of Graves' disease. Intolerance reactions to other medication were observed in 27% of cases, explaining fear of further medication (51%) and resulting avoidance behaviour (49%).