Although epidermolysis bullosa acquisita (EBA) can be seen at any age, it has an increased prevalence in adulthood. The presentation of EBA is varied, with five clinical patterns being described so far.
Patients with classical EBA show skin fragility and the formation of non-inflammatory tense bullae that are prone to rupture. These lesions develop more on sites subject to minor trauma, such as the back of the hands, knuckles, elbows, knees and feet. The blisters heal with scarring and the formation of small inclusion cysts in the epidermis, termed milia . Mucosal involvement is noted.
Bullous pemphigoid-like EBA shares clinical features with bullous pemphigoid, with patients presenting with lesions that are widespread, occurring in the trunk, extremities and skin folds . Being surrounded by inflamed skin, the blisters are usually tense, with pruritus a common finding. Milia and scarring are not prominent.
A mucous membrane variant, termed cicatricial pemphigoid-like EBA, manifests with erosions and scarring on mucosal surfaces such as the mouth, conjunctiva, upper esophagus, vagina and anus . The features of classical EBA may be absent in such cases.
The Brunsting-Perry pemphigoid-like variant of EBA occurs with bullae primarily on the head and neck region. Lesions often tend to heal with scarring with the involvement of mucosal lining being uncommon .
Immunoglobulin (Ig) A bullous dermatosis-like EBA appears with an annular arrangement of bullae seen characteristically in linear IgA bullous dermatosis . Mucous membranes can be affected.
EBA rarely shows up in children, with the mucous membranes being more frequently involved.
EBA can occur concurrently with a variety of systemic diseases, such as systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), rheumatoid arthritis, amyloidosis, thyroiditis, leukemia, diabetes etc.
EBA shares many clinical and immune-pathological features with other subepithelial blistering disorders and so its identification may hence be challenging. A thorough patient history and full skin examination help to narrow the differential diagnosis. Additional tests must be performed to confirm the disease.
The histopathological findings vary with the clinical subtype, with early lesions showing blister formation along the dermal-epithelial junction (DEJ) with adjacent papillary edema . The intensity of inflammation may vary with the type of lesion encountered.
Direct immunofluorescence shows the deposition of immunoglobulins in almost all cases. Classical EBA presents with the deposition of IgG and complement along the DEJ. Some subtypes may also showcase the presence of IgA, IgM, factor B and properdin .
Indirect immunofluorescence using the salt-split skin technique may demonstrate the presence of antibody binding to the dermal side of the basement membrane. This test may help to differentiate EBA from other autoimmune disorders causing subepithelial blister formation .
Additional studies may be done to support a diagnosis of EBA in the setting of a negative immunofluorescence report. These include direct and indirect immunoelectron microscopy, enzyme-linked immunosorbent assay (ELISA), immunoblotting, immunoprecipitation and collagen immunomapping techniques  .