INTRODUCTION: Drug hypersensitivity syndrome (DHS) induced by sulfasalazine is a serious systemic delayed adverse drug reaction, which is associated with significant morbidity and mortality. PATIENT CONCERNS: A 52-year-old man was hospitalized for developing a rash after 3 weeks of sulfasalazine treatment for ulcerative colitis (UC). DIAGNOSIS: The patient was diagnosed with DHS based on his drug history, clinical manifestations, and laboratory test results. INTERVENTIONS: The patient was administered intravenous glucocorticoids. The patient's condition improved after treatment with human immunoglobulin and antihistamines. OUTCOMES: Combination therapy of glucocorticoid and gamma globulin, the whole-body pruritus disappeared, and no new rash appeared. The whole-body rash subsided or turned dark red. CONCLUSION: This article describes the diagnosis and treatment process of a case of sulfasalazine-induced DHS and reviews the relevant literature to improve clinician understanding and avoid misdiagnosis and missed diagnosis.