Atypical IgA/IgG Pemphigus Involving the Skin, Oral Mucosa, and Colon in a Child: A Novel Variant of IgA Pemphigus?

Abstract

Immune-mediated blistering diseases are rare in childhood, with the subset of IgA pemphigus being extremely uncommon. A child with a bullous disorder of the oral mucosa, skin, and colon is reported because of the unusual nature of the clinical and laboratory findings. Immunofluorescence studies demonstrated both intercellular epidermal and basement membrane zone deposition of IgA and IgG antibodies, as well as intercellular colonic deposition of IgA antibodies. IgA and IgG ELISA tests were positive for desmoglein 3 as the intercellular epidermal antigen. The generation of multiple antibodies against several potential antigenic targets suggests epitope spreading may play a role in this disease. We believe this represents a novel variant of IgA pemphigus.

Cutaneous implantation of papillary thyroid carcinoma secondary to percutaneous ethanol injection into nodal metastasis

“…It is known that patients with autoimmune bullous disorders and inflammatory bowel disease often show autoantibodies to several autoantigens, suggesting that epitope-spreading phenomena might play a role in the pathogenesis. 7 Also, the rare coexistence of IgA pemphigus with LAD antibodies in the same patient as in our case supports this hypothesis. It is supposed that a primary immune response is initiated in inflamed colonic tissue resulting in cross-reactivity with cell surface antigens of the epidermis and its basement membrane zone.…”

Non-classical forms of pemphigus: pemphigus herpetiformis, IgA pemphigus, paraneoplastic pemphigus and IgG/IgA pemphigus

“…60 Three other cases were also called IgG/ IgA pemphigus, despite presenting negative DIF 128 or only intercellular IgG by DIF (but both intercellular IgG and IgA by IIF) or only intercellular IgA by DIF (but both intercellular IgG and IgA by IIF). 63,129 Two of these cases differ from all of the others by also showing IgG 63 or IgG and IgA in the BMZ by DIF. 124 …”

“…59 There are some reports of cases with presence of both IgA and IgG antibodies, which raises the question of whether pemphigus with both IgG and IgA autoantibodies is a subset of IgA pemphigus or not. 63 The subclass of in vivo-bound and circulating IgA autoantibodies has also been determined and is exclusively IgA1. 49,55,61 Enzyme-linked immunosorbent assay (ELISA) can be used for the diagnosis of IgA pemphigus and for detection of autoantibodies in individual patients.…”

Overlap of IgA Pemphigus and Linear IgA Dermatosis in a Patient with Ulcerative Colitis: A Mere Coincidence?

“…In a paediatric case of IgA/IgG pemphigus with a clinical picture similar to our patient, colonoscopy revealed colonic inflammation and intercellular IgA deposition (11), supporting a pathophysiological link between cutaneous and intestinal inflammation and IgAassociated autoreactivity. Patients with autoimmune bullous disorders and inflammatory bowel disease (IBD) often show autoantibodies to several autoantigens, suggesting that epitope-spreading phenomena might play a role in the pathogenesis (11). Indeed, the coexistence of 2 autoimmune bullous disorders in the same patient is a rare event that supports the hypothesis of intermolecular epitope-spreading.…”