Linear arrangement of neutrophils along the Basal layer in bullous pemphigoid: a unique histological finding.

Bullous pemphigoid is an inflammatory autoimmune subepidermal bullous disease with distinct immunohistological features. We report an unusual case of a 59-year-old woman with a bullous eruption whose lesional skin biopsy showed a subepidermal blister with a linear arrangement of neutrophils, mimicking linear IgA bullous dermatosis. However, direct immunofluorescence studies demonstrated IgG and C3 linear deposition along the basement membrane zone, compatible with bullous pemphigoid. We suggest that bullous pemphigoid should therefore be considered in the differential diagnosis of neutrophil-rich subepidermal bullous diseases along with dermatitis herpetiformis and linear IgA.