DRESS syndrome: an unlikely diagnosis with an unlikely cause.

Drug reaction with eosinophilia and systemic symptoms syndrome is a rare and severe adverse drug reaction which is potentially life-threatening. We report a case of a 66-year-old male, with no prior history of allergies, who went to the emergency department with fever, headache and a rash, 12 days following receiving metronidazole for 7 days. He had no recent trips, contact with sick people or animals. The authors aim to alert to an uncommon and serious syndrome caused by an unlikely drug.