Upadacitinib for the treatment of refractory bullous pemphigoid: a case report and literature review.

Bullous pemphigoid (BP) is a common autoimmune subepidermal blistering disorder that mainly affects elderly individuals aged ≥70 years. Systemic glucocorticoids serve as first-line treatment, and immunosuppressants or biological agents such as dupilumab are added for patients with suboptimal responses. However, a proportion of patients exhibit suboptimal responses or cannot sustain therapeutic benefits under these standard therapeutic regimens, representing an important unmet clinical need. We describe a 74-year-old patient with refractory BP who did not achieve adequate disease control despite sequential treatment with methylprednisolone, mycophenolate mofetil, cyclosporine, and dupilumab. The addition of upadacitinib resulted in substantial clinical improvement and durable disease stability. We also examine existing literature concerning salvage therapeutic options for refractory BP and the real-world application of upadacitinib in this disease. As this is a single-case observation, our work intends to offer clinical insights for the management of difficult-to-treat BP.