Linear IgA disease (LAD) constitutes a heterogeneous group of chronic, subepidermal, blistering mucocutaneous autoimmune diseases featuring an immune response to hemidesmosomal proteins solely driven by IgA. Autoantigens in LAD are LAD-1 and LABD-97, which are both cleavage products of the extracellular domain of BP180, as well as BP180 itself. In another subtype of LAD, type VII collagen serves as autoantigen. In addition to a spontaneous emergence of disease, LAD can also be drug-induced. LAD exhibits a bimodal peak of onset and predominantly emerges in children 4-5 years old and in adults in the 5th decade of life. LAD typically presents with grouped, tense skin blister (“string of pearls”) on urticarial, erythematous patches. Most LAD patients suffer from severe itch. 80% of patient show in addition erosions on mucous surfaces, which can cause scarring. LAD with predominant disease manifestation on mucous membranes is clinically indistinguishably from mucous membrane pemphigoid. LAD has been associated with a number of cancers and other inflammatory diseases, especially with colitis. LAD is diagnosed based on the clinical presentation, histopathology, direct and indirect immunofluorescence as well as detection of autoantibodies by Western blot utilizing recombinant proteins as antigens. LAD is of recalcitrant to treatment. The treatment of first choice is dapsone. LAD clinically resembles other pemphigoid diseases as well as dermatitis herpertiformis Duhring, from which it was distinguished as separate disease in 1979, which complicates early diagnosis.
- Specific challenges associated with the recognition of the condition
Rare disease, often misdiagnosed as Dermatitis herpertiformis Duhring, BP or MMP.
- Specific challenges associated with the diagnosis
Histopathology is unspecific, closely resembling other pemphigoid diseases. Indirect immunofluorescence on monkey esophagus is often negative. Frequently, Western blotting is required to detect antibodies, which requires specialized autoimmune labs.
- Specific challenges associated with the treatment
Disease is recalcitrant under treatment. There are no controlled trials evaluating treatments. Standard treatment is dapsone, which is only rarely used by most dermatologists but requires some experience in its use. Pediatric expertise is required when children are affected.
- Specific challenges associated with care of these patients over their lifespan – Quality of life issues – Gaps across the care continuum
The disease requires treatment by specialized dermatlologists often over many years. Specialists from other disciplines (e.g., ophthalmologists, gastroenterologists) are especially required when mucous membranes are involved.
Prevalence : Unknown