When Treatment Backfires: A Case Report of Sulfasalazine-Induced Hypersensitivity Syndrome in a Moroccan Patient With Crohn's Disease and Literature Review.

Sulfasalazine-induced hypersensitivity syndrome (SIHS) is a drug-specific variant of the syndrome known as drug reaction with eosinophilia and systemic symptoms (DRESS). It is a severe and unpredictable hypersensitivity reaction that can present with a spectrum of symptoms, ranging from mild rashes and unexplained fever to life-threatening systemic organ involvement. This diversity of symptoms often results in a diagnostic delay and/or misdiagnosis.