Linear IgA bullous dermatosis (LABD)

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Characterized by symmetrical, tense, sausage-like bullae or vesicles in annular or polycyclic plaques.

Lesions described as string of pearls or crown of jewels.

Center of lesions may be clear or crusted.

May involve mucous membranes.

Itching is variable.

Biopsy of skin shows sub epidermal blister formation with edema and neutrophilic infiltration.

Immunofluorescence shows IgA deposits along epidermal basement membrane zone in a linear pattern.

Caused by specific IgA autobodies targeting 97-kDa and sometimes 120-kDa antigenic fragments of basement membrane component BP180 in skin and mucosa.

Autoantibodies mediate tissue injury via plasminogen and neutrophils.

Autoantibody induced injury leads to collagen degradation and blister formation.

Commonly caused by medications.

Vancomycin is the most common precipitating agent, but penicillin, cephalosporins, ACE inhibitors, NSAIDs also implicated.

Reported to be associated with autoimmune diseases, inflammatory bowel disease and malignancy.

Occurs more frequently in children.

Process may last months to years in children and known as chronic bullous disease of childhood.

Treatment is dapsone, which can inhibit neutrophil dermatological conditions by impairing neutrophil activation and recruitment.

Steroids have limited role, and other therapeutic agents include: erythromycin, dicloxacillin, sulfa drugs, and mycophenolate mofetil.