Linear IgA and IgG bullous dermatosis

Abstract

Childhood linear immunoglobulin A dermatosis is a rare autoimmune vesiculobullous disease. It results in linear deposition of autoantibodies (immunoglobulin A) against antigens in the basal membrane zone, leading to subepidermal cleavage. Additional depositions of immunoglobulin G and complement-3 might occur. It is still debated whether concomitant findings of immunoglobulins A and G should be considered a subtype of this dermatosis or a new entity. Further studies are needed to recognize this clinical variant.

Previously misdiagnosed linear IgA dermatosis resolved with dapsone

“…Anti-BMZ isotype reactivity sounds found an association with IgA autoantibodies for younger patients and IgG for older patients 3. HLA-B8, HLA-DR3 and HLA-DQ2 rates increase in these patients 15. The mechanism for blister formation is not fully understood; however, it has been thought to be associated to IgA and complement-mediated neutrophil chemotaxis with autoantibodies producing neutrophil-rich infiltrates and subepidermal vesicles along the BMZ and linear IgA deposits, but IgG (25% of cases) and C3 can be detected 3–15.…”

“…Typical skin manifestations include multiple vesicles, blisters and erythema erosions along the extensor surfaces and torso. Histopathologically, LAD is characterised by neutrophilic infiltration and subepidermal blister with the presence of continuous linear IgA deposits at the BMZ 15. IgA autoantibodies in LAD were shown to target most characteristically the antigens proteins 97 and 120 kDa extracellular domains of BP180 (collagen XVII), termed the LAD antigen 1 (LABD97) and LAD-1, respectively 15 17.…”

“…Dapsone has been established as one of the most effective pharmacotherapies for LAD with remission of symptoms in 3 days; however, dapsone should be used carefully due to the risk of haemolysis and methemoglobinaemia (which are dose dependent), motor neuropathy, neutropaenia and hepatitis. Therefore, blood count, liver enzymes, methemoglobin and haptoglobin must be regularly monitored 15. Our qualitative literature review comprised several peer-reviewed articles, including case reports and reviews; however, this is the first case to our knowledge that the bullous skin lesions related to LAD are potentially associated to a possible occupational exposure to C. psittaci and to consecutive misdiagnosis of severe eczema, dermatitis herpetiformis and fungal infection, as well as inappropriate treatments.…”

“…Although postinfective LAD usually peaks a few weeks after the original infection, this association cannot be overlooked. Additional differential diagnoses include: mucous membrane pemphigoid, pemphigoid gestations, lichen planus pemphigoides and anti-p200 pemphigoid 15. A rigorous skin examination biopsy, and moreover, detection of tissue-bound and circulating autoantibodies is necessary to separate bullous pemphigoid lesions from each other, and current guidelines still consider immunofluorescence the gold standard for the diagnosis 16 Table 1.…”

Aetiopathogenesis of severe cutaneous adverse reactions (SCARs) in children: A 9‐year experience in a tertiary care paediatric hospital setting

“…Taking into account the main studies on SJS/TEN, about 16% of cases remain idiopathic, without any history of drug intake, or any infections detected . In the present study, we included other bullous reactions, not belonging to the SCAR group: linear immunoglobulin A bullous disease (LABD), a widespread bullous eruption with typical annular disposition and evidence of linear deposition of IgA at the dermoepidermal junction under immunofluorescence and pemphigus.…”