Overlap of hereditary epidermolysis bullosa and dermatitis herpetiformis in an adult woman: case report

Abstract

Hereditary epidermolysis bullosa (EB) is a group of genodermatoses characterized by congenital skin fragility and trauma-induced blistering, whereas dermatitis herpetiformis (DH) is an autoimmune, intensely pruritic vesiculobullous disease associated with gluten sensitivity and granular IgA deposition in the papillary dermis. We report the case of a 39-year-old woman with lifelong skin fragility and congenital abnormalities, including fused lower limbs requiring surgical reconstruction in infancy and persistent anonychia, supporting an underlying hereditary form of EB. In adulthood, she developed recurrent, highly pruritic vesicles and bullae with a symmetric distribution on the extensor forearms and lower limbs, the groin, inframammary areas, and the oral mucosa. The eruption partially improved with topical clobetasol and markedly improved after adopting a gluten-free diet. Histopathology showed epidermal hyperkeratosis and acanthosis with a superficial perivascular lymphocytic infiltrate, and direct immunofluorescence demonstrated granular IgA (3+) and IgG (1+) deposition in the papillary dermis, consistent with DH. This overlap raises the possibility that chronic tissue injury and antigen exposure in hereditary EB may predispose to secondary autoimmune blistering disease, as suggested by recent evidence of circulating autoantibodies against cutaneous structural proteins in EB patients. This case highlights the importance of integrating congenital history, clinicopathologic correlation, and immunopathology when evaluating new-onset pruritic vesiculobullous eruptions in patients with lifelong skin fragility, and it underscores the potential for evolving immune-mediated blistering processes in hereditary EB.