Development of bullous pemphigoid in a patient with psoriasis and metabolic syndrome.

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease that most commonly affects adults older than 60 years, whereas psoriasis vulgaris (PV) is a chronic immune-mediated disease that affects both children and adults. Bullous pemphigoid and PV may coexist with each other as well as with various other internal disorders, which may lead to early death. We report the case of a 35-year-old man with a 15-year history of PV and obesity who developed tense blisters with annular arrangement and normal-appearing perilesional skin localized mainly on the trunk, arms, and legs resembling linear IgA bullous dermatosis. This case demonstrated the development of BP in a patient with chronic PV and metabolic syndrome. Although the nature of this unique coincidence is not clear, methotrexate (MTX) seems to be first-line regimen for such cases.