Acquired epidermolysis bullosa

Specialty: Skin.

• autoimmune subepidermal blisters
• bullous skin fragility of collagen VII

Why it occurs

• Autoimmune blistering disease characterized by the production of IgG type autoantibodies directed against type VII collagen, the main component of the anchoring fibrils of the dermoepidermal junction
• Association with inflammatory bowel disease (Crohn's disease or ulcerative colitis)
• Paraneoplastic manifestation secondary to lymphomas or chronic leukemias
• Association with other systemic autoimmune diseases such as lupus erythematosus or Hashimoto's thyroiditis
• Rare hypersensitivity reactions to certain immunomodulatory drugs.

Initial workup

Punch perilesional skin biopsy for conventional optical microscopy showing a subepidermal blister with variable inflammatory infiltrate. Perilesional skin biopsy for direct immunofluorescence (DIF) revealing linear deposition of IgG and C3 in the basement membrane area. Split skin immunofixation demonstrating antibody deposition on the dermal side (floor) of the blister, and ELISA for anti-collagen antibodies VII.

Standard management

• Prednisone — first-line systemic corticosteroid administered at immunosuppressive doses of 1 to 1.5 mg/kg/day orally, with a slow progressive reduction regimen
• Dapsone — sulfone useful for its ability to inhibit neutrophil chemotaxis in the ampulla, doses of 50 to 150 mg daily under strict control of blood count and glucose-6-phosphate dehydrogenase levels
• Ciclosporin or mycophenolate mofetil — corticosteroid-sparing immunosuppressants indicated for long-term maintenance
• Non-adherent silicone biological dressings for the protection of erosive areas and prevention of deforming scars.