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linear IgA bullous dermatosis (IgA pemphigoid)

Etiology: 1) pharmaceuticals a) vancomycin most common culprit b) captopril, amiodarone, ampicillin, amoxicillin, diclofenac, interferon-gamma, interleukin-2, iodine, lithium carbonate, penicillin G, phenytoin, piroxicam, rifampin, somatostatin, Bactrim/Septra, childhood vaccines 2) idiopathic Epidemiology: - uncommon - 0.6 cases/100,000/year Pathology: 1) subepidermal bulla 2) IgA deposition in a linear pattern along the epidermal basement membrane with or without C3 & IgG deposition 3) immunologically identical to chronic bullous disease of childhood 4) subcorneal collection of neutrophils * histopathology image [5] Clinical manifestations: 1) vesicles or blisters on erythematous base 2) vesiculopustular eruption with clear blisters that rapidly transform into pustules 3) pruritus 4) clustered or discrete lesions 3) distribution: a) trunk & proximal extremities most commonly involved b) relative sparing of mucous membranes c) ocular involvement in some cases * images [4,5] Laboratory: 1) skin biopsy: direct immunofluorescence shows deposition of intercellular IgA at epidermal surfaces 2) serum IgA antibasement membrane antibodies detected by indirect immunofluorescence a) routine serum testing generally performed with monkey esophagus as substrate b) sensitivity increased by use of NaCl-split human skin as substrate Differential diagnosis: - bullous pemphigoid - dermatitis herpetiformis - cicatricial pemphigoid - chronic bullous disease of childhood Management: 1) withdrawal of offending drug generally resolves disorder 2) systemic corticosteroids 3) dapsone 50-200 mg QD may be particularly useful [3] 4) sulfapyridine

Related

chronic bullous disease of childhood IgA pemphigus

General

autoimmune bullous disease (... pemphigus, bullous pemphigoid)

References

  1. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 168
  2. Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 288
  3. Medical Knowledge Self Assessment Program (MKSAP) 15, 16, 17. American College of Physicians, Philadelphia 2009, 2012, 2015
  4. DermNet NZ. Linear IgA bullous disease (images) http://www.dermnetnz.org/immune/linear-iga.html
  5. Haeberle MT, James WD (images) Medscape: Linear IgA Dermatosis (images) http://emedicine.medscape.com/article/1063590-overview