Generalized Annular Bullous Eruption—Diagnosis

Histopathologic examination of a biopsy specimen showed a subepidermal blister with a neutrophil-rich inflammatory infiltrate. Direct IF microscopy demonstrated linear deposits of IgG and C3 at the dermoepidermal junction (DEJ). No deposition of IgA, IgM, or fibrinogen was observed. When subjected to 1M sodium chloride direct IF microscopy, the specimen showed linear deposition of IgG and C3 along the dermal side of the artificial split. There was no reactivity against type VII collagen or laminin 332 on immunoblotting (Figure 4).