Antigen

■ Collagen VII; same as EBA Pathophysiology:

Autoantibodies to the noncollagenous domain of collagen type VII attract neutrophils, which release proteases and cause disruption of the basement membrane zone. Blister formation is below the lamina lucida because of the location of collagen VII.

Clinicopathologic Correlation:

Abbreviation: BMZ, basement membrane zone.

Classification Variants, Mutations, and Other:

■ Patients with systemic lupus erythematosus that develop bullous lupus have a high incidence of HLA-DR2.

Clinical:

There are three types of EBA characterized by:

■ Acral blisters that heal with milia and scarring (chronic noninflammatory mechanobullous disease) (Fig. 9A)

■ Widespread vesiculobullous disease like BP (inflammatory)

■ Scarring oral lesions in 30% to 50%. Many of these reclassified with mucous membrane pemphigoid

Histology:

■ Subepidermal blister (Fig. 9B)

■ Mixed infiltrates of lymphocytes, many neutrophils and eosinophils at the basement membrane zone (Figs. 9C and D)

■ Fibrin and mixed inflammatory cells (neutrophils, eosi-nophils) in the lumen of bulla (Fig. 9D)

Differential Diagnosis:

■ Bullous lupus erythematosus; bullous pemphigoid; antiepiligrin mucous membrane pemphigoid

Immunofluorescence:

■ DIF: linear IgG (100%) and C'(50%) at the basement membrane zone (Fig. 9E)

■ IIF: circulating antibodies that bind to the basement membrane zone in 50% of individuals

■ IIF-SSS: immunoreactants that bind to dermal side of dermal-epidermal split (Fig. 9F)

Was this article helpful?

0 0

Post a comment