Idiopathic Bullous Pemphigoid With Concurrent Gingival and Cutaneous Involvement: A Case Report.

Bullous pemphigoid (BP) is the most common autoimmune blistering disease, primarily affecting older adults and typically presenting with intensely pruritic, tense cutaneous bullae. While mucosal involvement is more common in other blistering disorders such as mucous membrane pemphigoid, it can occasionally occur in BP. This atypical presentation may confound diagnosis and cause treatment delays. Here, we report the case of a 67-year-old woman with idiopathic BP involving both cutaneous and oral mucosal surfaces. The disease began with a single bulla on the ear and a pruritic rash across the upper back, eventually progressing to widespread cutaneous bullae with painful gingival involvement. After a suboptimal response to prednisone and mycophenolate mofetil, remission was successfully achieved with rituximab. This case underscores the diagnostic complexity and treatment challenges often seen in BP with mucosal involvement. Early recognition of atypical variants and careful histopathologic assessment are essential for guiding effective therapy.