Psoriasis bullosa acquisita

Area of Science:

• Dermatology
• Immunology
• Autoimmune Blistering Diseases

Background:

• Chronic plaque psoriasis is a common inflammatory skin condition.
• Autoimmune subepidermal blistering diseases, like bullous pemphigoid and epidermolysis bullosa acquisita, involve autoantibodies against basement membrane components.
• Co-occurrence of psoriasis and autoimmune blistering diseases is rare, with the specific autoantigen often undetermined.

Observation:

• A 51-year-old male with a 20-year history of psoriasis developed a blistering eruption mimicking bullous pemphigoid, erythema multiforme, and epidermolysis bullosa acquisita.
• Investigations revealed IgG autoantibodies binding to the dermal side of split skin, localized to the lower lamina lucida/upper lamina densa.
• Immunoblotting showed serum reactivity to 200- and 260-kDa antigens. Immunofluorescence studies demonstrated absent staining on recessive dystrophic epidermolysis bullosa skin, indicating a link to type VII collagen.

Findings:

• The patient's autoantibody showed specific binding patterns related to type VII collagen.
• The clinical presentation and immunopathological findings suggest a distinct autoimmune blistering disease associated with psoriasis.
• The patient responded well to a combination therapy including intravenous immunoglobulin, corticosteroids, dapsone, and mycophenolate mofetil.

Implications:

• This study identifies a potential autoantigen associated with a rare blistering eruption in a psoriatic patient.
• The findings suggest a novel autoimmune blistering disease, proposed as 'psoriasis bullosa acquisita'.
• Further research is needed to confirm the role of type VII collagen or associated components in the pathogenesis of this condition.