Monitoring and analysis of drug therapy in a patient with drug reaction with eosinophilia and systemic symptoms syndrome caused by pantoprazole: A case report

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a severe T-cell–mediated adverse cutaneous reaction characterized by rash, fever, and visceral involvement following prolonged drug use. It is rarely induced by proton pump inhibitors, with no prior reports documenting pharmacist-identified pantoprazole-related DRESS syndrome and subsequent intervention. A female in her early 60s (Han Chinese ethnicity) was admitted to the intensive care unit of Xiangtan Central Hospital (Xiangtan, China) in mid-2024 for thoracoabdominal pain caused by a fall, and pantoprazole was initiated for stress ulcer prophylaxis on the hospital day 2. Twenty-six days after pantoprazole initiation, the patient developed diffuse macular erythema with desquamation, and her eosinophil percentage increased from 0.5% to 7.8% after 2 days of rash onset. The clinical pharmacist initially suspected meropenem hypersensitivity and recommended discontinuation of this agent; however, 5 days after the onset of rash, leucopenia was observed with the eosinophil percentage peaking at 18.4%, and subsequent discontinuation of pantoprazole resulted in defervescence within 48 h, gradual resolution of the rash, and normalization of blood counts within approximately 10 days of drug cessation. Despite the complex pathophysiology and diagnostic challenges associated with DRESS syndrome, the pharmacist’s identification of the suspected drug and targeted intervention achieved favorable outcomes, providing clinical reference for further research on DRESS syndrome.