Abstract: A 47-year-old female diagnosed with erythema elevatum diutinum was initiated on dapsone therapy at a dose of 100 mg/d. Three weeks later, she presented with high fever, lymphadenopathy, jaundice, abdominal pain, generalized edematous erythema, and liver dysfunction. Computed tomography (CT) at a local hospital revealed an enlarged gallbladder with pericholecystic fluid, leading to a misdiagnosis of acute cholecystitis and a subsequent cholecystectomy. During the initial postoperative period, her liver enzymes decreased significantly, her body temperature normalized, and her generalized skin condition transiently improved. However, her condition subsequently relapsed, characterized by recurrent fever, skin erythema and edema, accompanied by a periumbilical yellow exudate, prompting her presentation to our hospital. Upon admission, genetic testing revealed an HLA-B*13:01 positive status. Combined with her typical clinical manifestations and medication history, a definitive diagnosis of dapsone hypersensitivity syndrome (DHS) was established. She was treated with intravenous methylprednisolone (80 mg/d) and symptomatic supportive care, resulting in the normalization of her temperature and the gradual resolution of the rash. This case highlights the critical need for preemptive HLA-B*13:01 genetic screening prior to initiating dapsone therapy to effectively prevent the onset of DHS.

Key words: dapsone, dapsone hypersensitivity syndrome, cholecystitis, HLA-B*13:01