DOI: https://doi.org/10.36347/sasjm.2026.v12i09.006

Pages: 879-882

Background: Drug-induced bullous pemphigoid is a rare cutaneous adverse reaction linked to various systemic medications. Secukinumab, an interleukin-17A inhibitor widely used for moderate-to-severe psoriasis, has rarely been implicated in the development of bullous pemphigoid. Case Presentation: A 79-year-old male with a 20-year history of severe plaque psoriasis—previously recalcitrant to topical corticosteroids and methotrexate—was treated with secukinumab. After 10 months of successful therapy, treatment was interrupted for 3 months due to poor adherence before being resumed. One month post-reinitiation, the patient developed intense pruritus and tense bullous lesions on the upper and lower extremities, rapidly generalizing within days. Histopathological examination revealed a subepidermal split, and direct immunofluorescence demonstrated linear, homogeneous deposition of C3 and IgG along the basement membrane zone, confirming bullous pemphigoid. Treatment with topical corticosteroids and oral doxycycline led to significant clinical improvement within two weeks. However, re-challenge via his subsequent scheduled secukinumab injection triggered a rapid flare of bullous lesions. Definitive discontinuation of secukinumab resulted in lesion clearance and complete resolution. Conclusion: Clinicians should remain vigilant regarding the rare potential of interleukin-17A inhibitors, such as secukinumab, to induce autoimmune blistering conditions like bullous pemphigoid, particularly following drug reintroduction or interruption.