Epidermolysis Bullosa Acquisita: Overview and Treatment Steps

Overview

Epidermolysis bullosa acquisita (EBA) is an autoimmune disorder due to autoantibodies to Type VII collagen. EBA may present as a noninflammatory bullous lesion with acral distribution that heals with atrophic scarring (similar to porphyria cutanea tarda). EBA may also present as an inflammatory bullous disorder clinically similar to bullous pemphigoid, cicatricial pemphigoid, localized scarring pemphigoid, or linear IgA disease. Diagnosis is confirmed by special immunofluorescent studies using salt split skin, staining of histologic sections demonstrating the blister to identify laminin at the roof of the blister, or with electron microscopy. Therapy is generally difficult, and most patients have a chronic progressive disorder lasting many years. The aggressiveness of treatment should correlate with the severity of disease. No universally effective therapy has been found for those patients with the classic disorder of skin fragility and noninflammatory lesions.

First Steps

1. For patients with mild or slowly progressive EBA, topical management plus colchicines is the initial therapy. More aggressive treatment may not be indicated, as potential therapies may have significant side effects.
2.  
3. Protect the affected area with soft dressings to prevent trauma.
4. Prescribe antibacterial emollients (bacitracin or mupirocin ointment) to reduce friction and prevent secondary infection.
5. Try intermediate to superpotent topical steroids.
6. Colchicine 0.6 mg to 2.0 mg/day may be effective. Treat for at least 6 months to determine efficacy. Diarrhea is an anticipated side effect in patients taking higher doses. Dapsone in low doses may be added in patients who do not completely respond and can not tolerate the maximum doses above.

Subsequent Steps

1. Systemic steroids and standard immunosuppressives (azathioprine, methotrexate, and cyclophosphamide) are often ineffective in EBA. Some patients with inflammatory lesions resembling bullous pemphigoid may respond to these therapies.
2. Cyclosporine 5-9 mg/kg/day with or without prednisone may dramatically improve severe disease and induce a remission. Renal function must be carefully monitored.
3. Extracorporeal photophoresis with or without cyclosporine may lead to remission after as little as a single treatment. As many as six or seven treatment cycles may be required.
4. High-dose intravenous immunoglobin (IVIG) 400mg/kg/day for 5 days, repeated every 4-6 weeks. The time between treatments may be extended gradually up to once every 3 months.

Complications and Undesired Consequences

1. The major pitfall is not recognizing EBA. Direct immunofluorescence is essential in the evaluation of most bullous eruptions.
2. Cyclosporin A has many side effects, and its prescription should be restricted to physicians with experience with this drug. Nephrotoxicity, dose-dependent elevation of liver function tests, immunosuppression, gingival hypertrophy, hypertrichosis, and neurologic side effects have all been reported. Toxic side effects are dose dependent, and can be reduced by monitoring blood levels.
3. Mucous membranes are often severely affected. The appropriate specialist (ophthalmologist, gastroenterologist, urologist, or gynecologist) should be consulted when there is significant involvement of the mucosal surfaces.