Epidermolysis Bullosa Acquisita (EBA)

What happens in EBA

The skin's top layer (epidermis) is attached to the deeper layer (dermis) by anchoring fibrils made of type VII collagen. In EBA, the immune system produces IgG antibodies against this collagen. The anchoring fibrils weaken, so the layers separate easily, forming blisters below the epidermis. Healing often leaves scars.

The name comes from the inherited condition dystrophic epidermolysis bullosa, which also involves type VII collagen but is caused by gene changes and starts at birth. EBA is "acquired" because it begins later in life and is autoimmune, not inherited.

Types and symptoms

Classic (mechanobullous) EBA

• skin that tears or blisters after minor friction or injury
• tense or fluid-filled blisters, sometimes bloody, on the backs of the hands, knuckles, elbows, knees, ankles and feet
• healing with scars, skin color changes and milia (tiny white cysts)
• nail damage or loss
• hair loss with scarring on the scalp

Inflammatory EBA

• widespread, itchy, red, blistering rash that can look like bullous pemphigoid
• less scarring than the classic form

Mucous membrane involvement

• mouth ulcers and blisters
• eye inflammation and scarring, which can affect vision
• narrowing of the esophagus causing swallowing difficulty
• involvement of the voice box (larynx) and airway (rare)

This form resembles mucous membrane pemphigoid.

Causes and associations

The trigger is unknown. EBA is more common in people with certain immune genes and has been linked to:

• Crohn's disease and ulcerative colitis (type VII collagen is also present in the gut)
• systemic lupus erythematosus (a related condition, bullous lupus, also targets type VII collagen)
• rarely, other autoimmune diseases and blood cancers

Diagnosis

Because EBA looks similar to other blistering diseases, specialized tests are needed:

• Skin biopsy showing a split below the epidermis.
• Direct immunofluorescence (DIF): shows IgG deposited along the junction between skin layers in a pattern typical of EBA.
• Salt-split skin test: antibodies bind to the floor of the split (dermal side), unlike in pemphigoid where they bind to the roof.
• Blood tests (ELISA) for antibodies against type VII collagen.
• Eye, mouth, throat and gut assessments as needed.

Treatment

EBA can be hard to treat and often needs a combination of approaches under a dermatologist experienced in blistering diseases:

• Colchicine and dapsone for milder disease
• Oral corticosteroids for flares
• Steroid-sparing immunosuppressants: azathioprine, mycophenolate, cyclosporine
• Rituximab and IV immunoglobulin (IVIG) for severe or resistant disease
• Topical steroids for localized blisters

Skin and wound care

• protect the skin from friction and injury: padded clothing, soft shoes, gloves
• lance large blisters with a sterile needle to relieve pressure, leaving the roof in place
• use non-stick dressings and keep wounds clean
• watch for infection
• soft diet and good dental care for mouth involvement
• eye care with an ophthalmologist

Outlook

EBA is a chronic disease that can wax and wane for years. Some people achieve remission with treatment. Scarring, eye damage and narrowing of the esophagus are the main long-term risks, which is why early specialist treatment matters.

Frequently asked questions

What is epidermolysis bullosa acquisita?

It is a rare autoimmune blistering disease of adults in which antibodies attack type VII collagen, the protein that holds the skin layers together. The skin becomes fragile and blisters easily, especially over joints, and heals with scars.

Is EBA the same as epidermolysis bullosa?

No. Inherited epidermolysis bullosa is caused by gene changes and appears at birth or in infancy. EBA is acquired, autoimmune and usually starts in adulthood, though it affects the same anchoring protein in some forms.

Is EBA contagious?

No. EBA is an autoimmune condition and cannot be spread to other people. Open blisters can become infected, however, so good wound care matters.

Can epidermolysis bullosa acquisita be cured?

There is no guaranteed cure, but treatment can control blistering, and some people go into long-term remission. Early diagnosis and specialist care reduce scarring and complications.