Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS) With Eosinophilic Cholecystitis Triggered by Topical Diclofenac

A 64-year-old man presented with a diffuse rash accompanied by abdominal fullness and anorexia. Two and a half weeks earlier, he injured his foot and began applying topical 1% diclofenac gel several times a day. His clinical course was notable for fever, an absolute eosinophil count of 7.49 × 10⁹ cells/L, transaminitis, and eosinophilic cholecystitis. An extensive work-up for other causes of eosinophilia was negative, and the patient met clinical criteria for drug reaction with eosinophilia and systemic symptoms (DRESS). His symptoms and laboratory abnormalities gradually improved without corticosteroid treatment. This represents, to our knowledge, the first case of DRESS triggered by topical diclofenac.