Dermatitis herpetiformis with fibrillar IgA deposition and unusual histologic findings

DH: dermatitis herpetiformis DIF: direct immunofluorescence INTRODUCTION Dermatitis herpetiformis (DH) is an autoimmune, subepidermal blistering disease associated with gluten sensitivity. It commonly manifests as intensely pruritic papules and vesicles on the extensor surfaces of extremities in a symmetric distribution. Classic histologic findings and data from direct immunofluorescent (DIF) staining often permit for a prompt diagnosis; however, dermatopathologists should be aware of rare and misleading histologic features and DIF patterns that can delay the diagnosis. We present an exceedingly rare case in which there was reasonably strong clinical suspicion for DH but misleading histologic and DIF stain findings. Clinicopathologic correlation allowed for a proper diagnosis and subsequent biopsies showed classic findings.