Abstract: Objective: To explore the feasibility of utilizing dapsone (DDS) under intensive clinical monitoring for the treatment of refractory dermatoses in patients carrying the HLA-B*13:01 allele, with a focus on the early identification and intervention of dapsone hypersensitivity syndrome (DHS). Methods: Two patients with HLA-B*13:01 and refractory skin diseases (diagnosed with dermatitis herpetiformis and urticarial vasculitis, respectively) were selected. After providing informed consent, they were administered DDS and subjected to daily body temperature monitoring. Upon occurrence of fever (＞37.5℃), DDS was discontinued immediately. Complete blood count and liver/kidney function tests were performed, followed by methylprednisolone treatment. Concurrently, the enzyme-linked immunospot (ELISpot) assay was employed to detect DDS-specific T-cell immune responses in peripheral blood. Results: The two patients developed fever accompanied by liver function abnormalities on day 22 and day 38 of medication, respectively. Prompt discontinuation of DDS and initiation of glucocorticoid therapy led to symptom resolution without progression to severe DHS. ELISpot assays demonstrated increased DDS-specific IFN-γ secretion in both patients, confirming DDS as the causative drug. The primary diseases were controlled post-treatment, with no severe adverse reactions observed. Conclusion: For HLA-B*13:01-positive patients with refractory dermatoses lacking alternative treatment options, the use of DDS with thorough informed consent and stringent monitoring can achieve effective management of the primary disease. Early recognition and intervention can prevent the progression of DHS, providing a clinical reference for the personalized use of this medication in patients carrying susceptible alleles.

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