Combination biologic therapy in bullous pemphigoid: two case reports and a focused review

Bullous Pemphigoid (BP) is the most common autoimmune blistering disorder, predominantly affecting elderly patients and often requiring prolonged immunosuppression. Conventional therapies are frequently limited by adverse effects and incomplete disease control, particularly in refractory cases. Increasing understanding of BP pathogenesis has supported the use of targeted biologic therapies; however, evidence regarding combination approaches remains limited. We report two cases of refractory BP treated with combination biologic therapy and provide a focused review of the literature. In the first case, partial response to omalizumab was followed by complete disease control after the addition of dupilumab, allowing successful corticosteroid discontinuation. In the second case, a patient with concomitant psoriasis achieved marked improvement with dupilumab in combination with ongoing IL-17 inhibition (secukinumab), resulting in effective control of both BP and psoriasis. These observations highlight the benefit of simultaneous targeting of complementary inflammatory pathways, including IgE-mediated, Th2, and Th17 axes. Combination biologic therapy may represent a promising strategy in refractory BP, particularly in patients with complex immunologic profiles or coexisting inflammatory diseases.