Long-term upadacitinib treatment in a patient with atopic dermatitis, bullous pemphigoid, and alopecia areata: a case report and review of the literature.

Atopic dermatitis (AD), bullous pemphigoid (BP), and alopecia areata (AA) are immune-mediated dermatologic diseases characterized by distinct clinical features but partially overlapping immunopathogenic mechanisms. Their coexistence in a single patient is uncommon and may pose significant diagnostic and therapeutic challenges. We report the case of a 33-year-old woman with long-standing moderate-to-severe AD who subsequently developed BP, confirmed by histopathology and direct immunofluorescence. Initial treatment with systemic corticosteroids and conventional immunosuppressants, including azathioprine followed by cyclosporine, resulted in only transient improvement and was limited by adverse effects. Dupilumab was therefore initiated, leading to marked improvement of BP while maintaining remission of AD. However, after approximately six months of therapy, the patient developed new-onset patchy AA. Dupilumab was discontinued, and treatment was switched to upadacitinib, a selective Janus kinase 1 (JAK1) inhibitor. Early clinical improvement was observed after six weeks, with progressive hair regrowth and stable BP activity. Complete remission of BP was achieved after twelve weeks and complete remission of AA after twenty-four weeks, while remission of AD was maintained. Disease control was sustained throughout a twenty-four -month follow-up, without significant adverse events. This case underscores the diagnostic and therapeutic complexity associated with the coexistence of multiple immune-mediated dermatologic diseases. The sequential emergence of AD, BP, and AA highlights the challenges posed by overlapping inflammatory pathways and the need for alternative therapeutic strategies when pathway-specific treatments prove insufficient or poorly tolerated. These observations support the concept that broader immunomodulatory approaches targeting shared signaling pathways may enable simultaneous control of multiple inflammatory conditions. In this context, inhibition of the JAK-STAT pathway may represent a promising integrated therapeutic strategy in selected patients with complex immune-mediated dermatologic comorbidities.