Possible Dual Immunoreactivity for Laminin-332 and Type VII Collagen in a Case with Vancomycin-Induced Linear Iga Bullous Dermatosis Manifesting as Erythroderma

We report a unique case of vancomycin-induced linear IgA bullous dermatosis (LABD) presenting as erythroderma. Direct immunofluorescence showed a linear IgA deposition at the dermal side of the basement membrane zone (BMZ), and double immunostaining using patients’ skin as a substrate revealed that the in vivo IgA signal co-localized with laminin-332 and type VII collagen. Our case is the first documentation of vancomycin-induced LABD, in which the pathogenic IgA deposit would concomitantly recognize the two distinct antigens at the dermal BMZ.