Bullous Systemic Lupus Erythematosus As the Initial Presentation of Systemic Lupus Erythematosus.

Bullous systemic lupus erythematosus (BSLE) is a rare, autoantibody-mediated subepidermal blistering disorder. It typically occurs in patients with established systemic lupus erythematosus (SLE). We report a 55-year-old Hispanic female with no prior SLE history who developed bullous lesions later identified as BSLE. Skin biopsy and direct immunofluorescence showed subepidermal blisters, and these findings, along with her clinical presentation, confirmed the diagnosis. Linear deposition of IgG, complement C3, and collagen VII antibodies was found, which is highly characteristic and supportive of BSLE. In this clinical context, these immunopathologic findings are considered diagnostic; however, confirmation can be further supported by a rapid response to dapsone therapy. Oral dapsone therapy resulted in complete resolution within weeks. No residual scarring or pigmentation remained. This case highlights the importance of considering BSLE even in patients without classical lupus features.