Epidermolysis Bullosa Acquisita

Excerpt

Epidermolysis bullosa acquisita (EBA) is a rare, chronic autoimmune blistering disease that impacts both the skin and mucous membranes. This condition arises due to autoantibodies targeting type VII collagen—a crucial component of anchoring fibrils within the dermal-epidermal junction (DEJ). These anchoring fibrils are responsible for attaching the epidermis to the underlying dermis. When autoantibodies bind to type VII collagen, they cause the detachment of the epidermis, leading to skin fragility, blisters formation, erosions, scaring, milia formation, and nail loss.

Although EBA can manifest in various phenotypes clinically, the classical mechanobullous and inflammatory forms are the most common presentations. Classic mechanobullous EBA resembles dystrophic epidermolysis bullosa (EB), with bullae and erosions developing at sites of trauma. However, it is noteworthy that EBA is a distinct bullous disorder primarily affecting adults, whereas EB is more commonly found in children. Both conditions share a common name due to their presumed similar clinical features.

Conversely, the inflammatory forms of EBA present clinical manifestations similar to those found in other autoimmune blistering disorders, including bullous pemphigoid (BP), mucous membrane pemphigoid (MMP), IgA bullous dermatosis, and Brunsting-Perry pemphigoid.

Furthermore, EBA has been reported in association with various systemic diseases, including inflammatory bowel disease (IBD), thyroiditis, rheumatoid arthritis, hepatitis C infection, and diabetes mellitus.