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The prevalence is unknown, but the incidence is estimated at 1/96,200 new cases per year.

Epidermolysis bullosa acquisita (EBA) is an acquired disease with onset typically in middle-aged adults but can rarely occur in childhood. The disease manifests in several possible ways. The classical presentation is reminiscent of hereditary dystrophic EB with skin fragility, blisters and erosions and skin scarring. There is marked skin fragility with skin blisters and erosions over trauma-prone areas of the skin that results in skin scarring. This form is relatively non-inflammatory. Mucous membrane lesions and nail dystrophy are common. A second possible clinical presentation is an inflammatory bullous eruption reminiscent of the autoimmune bullous disease, bullous pemphigoid. These bullae are on inflammatory plaques and may be flexural rather than over trauma-prone areas. A third possible clinical presentation is mucosal-centered with blisters, erosions and scarring of the conjunctival and oral mucosae, but may also involve the larynx and urethra. A fourth possible presentation is an IgA anti-type VII collagen mediated disease reminiscent of IgA bullous dermatosis and dermatitis herpetiformis. Diseases frequently associated with EBA include inflammatory bowel diseases (Crohn's disease and ulcerative colitis) and systemic lupus erythematosus.

EBA is caused by IgG autoantibodies generated against type VII collagen in the skin located at the dermal-epidermal junction. Type VII collagen is the major component of anchoring fibril structures located at the dermal-epidermal junction just beneath the lamina densa. These structures hold the epidermal and dermal layers of skin together. The autoantibodies against type VII collagen perturbs the function of anchoring fibrils and the adherence between these two main layers of skin is compromised and prone to blistering.

Diagnosis is made by histology and direct immunofluorescence (DIF) of skin biopsies, salt-split skin DIF, indirect immunofluorescence (IIF) of patient's serum, salt-split skin IIF, immunoblotting of patient serum against type VII collagen, detection of anti-type VII collagen autoantibodies by ELISA and/or immune-electron microscopy of a skin biopsy.

The differential diagnosis should include other subepidermal, autoimmune bullous diseases.

In EBA patients without inflammatory bowel disease, oral colchicine is the first-line treatment. Dapsone may be helpful in some patients. Oral cyclosporine A controls the disease, but its nephrotoxic side-effects limit its use. In the classical form of EBA, other types of immunosuppressive therapy (such as systemic steroids, azathioprine, mycophenylate mofetil,) are often ineffective, but may be useful in the inflammatory varieties of EBA. Although further trials are necessary, encouraging results have been obtained with other approaches such as intravenous immunoglobulin therapy, extracorporeal photochemotherapy and, more recently, rituximab therapy.

EBA is a chronic, incurable disease that leads to dystrophic scarring and milia. During the disease course, the inflammatory forms may evolve to resemble the classical form and vice-versa. Although not fatal, the progressive scarring and involvement of the oral and ocular mucosae can be functionally disabling.