DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms) is a severe, rare and potentially lethal idiosyncratic condition associated with the use of some drugs. Given its broad spectrum of presentation, clinical suspicion is essential for management, since it requires the immediate withdrawal of the culprit drug, support measures and the use of corticosteroids as the first line of treatment. We report a 24-year-old woman with a diagnosis of ulcerative colitis with joint involvement despite the use of infliximab, who presented symptoms, signs and laboratory compatible with DRESS syndrome on the third week after indicating sulfasalazine for her baseline disease.