Localized Bullous Pemphigoid of the Scalp and Face with Suspected Vulvar Involvement: A Case Report

Localized bullous pemphigoid (LBP) is a form of bullous pemphigoid (BP) confined to a limited anatomical area. Classification becomes less certain when clinically similar lesions occur at a distant site without site-specific immunopathologic confirmation. We report immunopathologically supported scalp/facial BP-spectrum disease with a temporally associated but unconfirmed vulvar eruption.

A 51-year-old woman presented with a 3-month history of pruritic erythema and tense bullae on the scalp and face and a 1-month history of erythematous scaly plaques with hemorrhagic bullous lesions in the vulvar region. Scalp histopathology showed a subepidermal blister with eosinophil-rich inflammation, and direct immunofluorescence (DIF) of perilesional scalp skin showed linear IgG and C3 deposition along the basement membrane zone. Infectious studies of the vulvar eruption were negative. Anti-BP180/230 serology, indirect immunofluorescence, salt-split skin studies, and anti-type VII collagen antibody testing were unavailable. Vulvar biopsy and DIF were not performed; therefore, vulvar BP could not be confirmed. With systemic and topical corticosteroids plus adjunctive minocycline, no new bullae developed by day 5, and the lesions markedly improved within 2 weeks. Methylprednisolone was subsequently tapered from 40 mg/day to a maintenance dose of 4 mg/day; minocycline and topical corticosteroids were discontinued after sustained clinical improvement. At 6 months, the disease remained clinically controlled on methylprednisolone 4 mg/day, with no new bullae or clinically evident recurrence. No treatment-related adverse events were observed.

The findings support localized BP/BP-spectrum disease of the scalp and face, while the vulvar eruption remains unconfirmed. The parallel treatment response is supportive but not diagnostic of vulvar BP. When feasible, lesions at sensitive sites should undergo site-specific biopsy and DIF. If biopsy is declined or impractical, pretreatment morphology should be carefully documented, diagnostic uncertainty should be acknowledged, and follow-up should assess for scarring and additional mucosal involvement.