Linear IgA Bullous Dermatosis and Chronic Bullous Disease of Childhood

« Back

Linear IgA Bullous Dermatosis and Chronic Bullous Disease of Childhood

Linear IgA Bullous Dermatosis and Chronic Bullous Disease of Childhood is a rare autoimmune subepidermal blistering disorder characterized by linear IgA deposition along the basement membrane zone. Adult onset disease most commonly affects elderly patients and is frequently drug induced, whereas pediatric disease is referred to as chronic bullous disease of childhood. The most common offending medication is vancomycin, with additional associations including penicillins, cephalosporins, and ACE inhibitors particularly captopril. Pathogenesis involves IgA autoantibodies directed against antigens derived from BP180 including LAD 1, a 120 kDa cleaved extracellular portion of BP180, and LABD 97, a 97 kDa fragment of LAD 1. Clinically, patients develop tense vesicles and bullae with urticarial plaques arranged in annular, polycyclic, or herpetiform patterns classically described as a crown of jewels. Lesions most often involve the lower trunk, thighs, groin, and buttocks. Drug induced cases may resemble Stevens Johnson syndrome or present with a morbilliform eruption. Histology shows subepidermal blistering with neutrophils aligned along the basement membrane zone and early basal vacuolar change. Direct immunofluorescence demonstrates linear IgA deposition along the basement membrane, while indirect immunofluorescence on salt split skin stains the epidermal side. Dapsone is the treatment of choice.

Epidemiology and Triggers

  • Elderly emperor penguin = Adult-onset LABD
  • Child penguin with chronic grandfather clock = Chronic bullous disease of childhood
  • Medication bottle = Drug-induced LABD
  • Delivery VAN = Vancomycin
  • Penicillin pencil = Penicillin
  • Cephalo-pod hat = Cephalosporins
  • CAPTAINS delivery ACE service = ACE inhibitors most often captopril

Pathogenesis

  • IgA HAY = IgA autoantibodies
  • Penguin LADY = LAD-1 antigen
  • 180 spin with confetti = 120 kDa portion of BP 180 antigen
  • 9-shaped balloon with 7-heaven halo = LABD 97 antigen

Clinical Presentation

  • Crown of jewels = Tense vesicles, bullae, urticarial plaques in cyclic or herpetiform arrangement
  • Jewels falling on lower trunk and groin = Commonly affected sites including lower trunk, thigh, groin, and buttocks
  • Stevie J’s burger = Drug-induced LABD with Stevens-Johnson syndrome-like or morbilliform appearance

Histology

  • Line of EMT first responders = Neutrophils lining the basement membrane zone with early basal vacuolar change
  • Stacks of IgA HAY = Linear IgA deposition along the basement membrane on DIF
  • Saltshaker in the air = Indirect immunofluorescence staining the roof on salt-split skin

Treatment

  • Dim sum = Dapsone