Diagnosis: Epidermolysis Bullosa Acquisita
Histology: Sections of punch biopsy from lip show a small subepidermal blister (Fig. 5). The adjacent squamous mucosa shows focal basal vacuolar changes with occasional dyskeratotic cells (Fig. 6). In addition there is mild pigment incontinence. The underlying stroma shows minimal inflammation with mild increase in number of interstitial cells. The differential diagnosis includes lupus mucositis vs. epidermolysis bullosa acquisita.
Direct immunofluorescence reveals strong linear deposition of IgG, C3, and IgM along the BMZ. These features are more consistent with epidermolysis bullosa acquisita than with lupus.
Clinical course: The patient was initially started on empiric IV acyclovir, PO fluconazole and a PPI pending culture and biopsy results. When HSV and CMV PCR were negative as well as fungal cultures, acyclovir was discontinued and the patient was treated with IV methylprednisolone. This was discontinued and she was started on PO prednisone once the patient was better able to tolerate PO intake. Appetite and food tolerance gradually improved after the initiation of steroids, and by the time of discharge the patient’s dysphagia and appetite had greatly improved. She had developed no new cutaneous blisters and noted healing of her lip erosions.
Epidermolysis bullosa acquisita (EBA) is a rare, acquired subepidermal bullous disease. It features IgG autoantibodies directed against the NC1 domain of collagen VII, a major structural component of the anchoring fibrils of the dermal-epidermal junction. EBA usually affects adults, however cases in children have been reported. No racial or gender predilection has been identified, but EBA may have a higher incidence in Koreans. The expression of distinct HLA alleles may have an important impact on the susceptibility for developing EBA, including HLA-DR2 which has increased occurrence in patients with EBA and bullous systemic lupus erythematosus.
The classic clinical phenotype features skin fragility, blisters, erosions, scars and milia on non-inflamed skin, often localized to trauma-prone surfaces such as elbows, knees, dorsal hands, and feet. Lesions heal with scarring and milia. Scalp involvement occurs in up to 20% of patients and may be associated with scarring alopecia, mimicking Brunsting-Perry pemphigoid.
Other clinical presentations include an “inflammatory” BP-like phenotype with widespread vesicles and bullae and a mucous-membrane pemphigoid disease. Erosions may be seen in the mouth, larynx, and esophagus leading to dysphagia and laryngeal stenosis. Involvment of the eyes may lead to blindness.
There are increased reports that EBA may be associated with a number of systemic diseases, including inflammatory bowel disease, SLE, myeloma, rheumatoid arthritis, thyroiditis, and diabetes.
Treatment consists of systemic corticosteroids and standard immunosuppressants including methotrexate, azathioprine, and cyclophosphamide. Other treatments include colchicine, dapsone, IVIG and most recently rituximab, which has been successful in treating patients with severe, widespread EBA refractory to other management.
This case was presented by Katherine Moritz MD, Brundha Balaraman, MD and Kara Nunley, MD.