Linear IgA Disease

Last Literature Review: August 2015 Last Update:

Medical Experts



Kristin M. Leiferman, MD
Co-Director, Immunodermatology Laboratory, Professor of Dermatology, and Adjunct Professor of Pathology, University of Utah
Medical Director, Immunodermatology, ARUP Laboratories

Linear IgA disease is a blistering disorder of the skin and mucous membranes that is also known as linear IgA bullous dermatosis (in adults) and chronic bullous disease of childhood (in children). Initially, broad serum testing, including pemphigoid and pemphigus panels and endomysial antibodies, should be performed unless a specific immunobullous skin disease type is suspected.


Indications for Testing

Presence of chronic blistering, urticarial plaques, eczematous skin disease after other, more common diseases ruled out

Laboratory Testing

  • Initial serum testing – pemphigoid and pemphigus panels and endomysial antibodies (all 3 tests for initial screening) or epithelial skin antibodies testing
    • Broad testing recommended unless a specific immunobullous skin disease type is suspected
      • IgA antibodies localized to epidermal side of split skin or showing a combined epidermal-dermal pattern
        • IgA antibodies showing dermal localization alone are rare but do occur
  • Serum IgA basement membrane zone (BMZ) antibodies by indirect immunofluorescence
    • Bind to epidermal, dermal, or combined epidermal-dermal areas of split skin
    • Positive in 60-70% of patients with linear IgA disease

Histopathlogy and Immunopathology

  • Histopathology – bullae are subepidermal with neutrophils along the BMZ and occasionally in dermal papillary tips
  • Perilesional skin biopsy (cutaneous direct immunofluorescence)
    • IgA BMZ antibodies in linear pattern present in 100% of patients
    • Complement and lesser intense linear IgG and/or IgM BMZ staining also may be present 

Differential Diagnosis


Epithelial basement membrane zone IgA antibody testing or epithelial skin antibodies to monitor disease activity and response to therapy



  • Prevalence – rare disorder
  • Age
    • Adult – average age of onset >60 years
    • Childhood – birth-10 years (average 4.5 years)
  • Sex – M<F; minimal

Risk Factors


  • Neutrophil involvement – usually greater in linear IgA disease
  • Eosinophil involvement – usually greater in pemphigoid and epidermolysis bullosa acquisita
  • Serum IgA basement membrane zone (BMZ) antibodies bind to epidermal, dermal, or combined epidermal-dermal areas of split skin
    • The linear IgA bullous disease antigen of 97 kDa (LABD97) and the 120 kD linear IgA disease antigen-1 (LAD-1) are cleavage products of bullous pemphigoid antigen 2 (BP180) and are major antigenic targets for IgA autoantibodies
    • Type VII collagen IgA antibodies may account for dermal staining on split skin
  • Both IgA and IgG BMZ antibodies may be found in tissue and serum of a subset of patients

Clinical Presentation

  • Papulovesicles, bullae, or urticarial plaques on extensor, central, or flexural sites with truncal involvement
    • May also appear annular or herpetiform
  • Variable lesion types similar to pemphigoid or epidermolysis bullosa acquisita
  • Classic presentation – “string of pearls” lesion consisting of grouped vesicles
  • Oral mucosa involvement – common
    • Ocular involvement – indistinguishable from ocular cicatricial pemphigoid
  • May exhibit severe pruritus
  • Perineal and perioral involvement common in children
  • Association with vancomycin and other drug exposure in drug-induced cases

ARUP Laboratory Tests

Additional detail about the tests below, including components and recommended use, can be found in the ARUP Immunobullous Disease Testing Comparison table


Additional Resources