IgA pemphigus: report of a case with immunoelectron localization of bound IgA in the skin

Rapid response of IgA pemphigus of subcorneal pustular dermatosis type to treatment with isotretinoin

Diagnosing IgA pemphigus and distinguishing between its 2 subtypes, intraepidermal neutrophilic IgA dermatosis type and subcorneal pustular dermatosis type, is important because treatment of IgA pemphigus has to be different from treatment of other blistering autoimmune dermatoses. We present a patient with subcorneal pustular dermatosis type of IgA pemphigus who rapidly responded to systemic treatment with isotretinoin. Specific diagnosis was established by detecting IgA serum activity to desmocollin 1 by indirect immunofluorescence microscopy on unfixed COS7 cells transfected with desmocollin 1. No IgA or IgG serum reactivity was found to recombinant forms of desmogleins 1 and 3 by an antigen-specific enzyme-linked immunosorbent assay. The disease was not effectively controlled by conventional therapeutic regimens. Systemic treatment with isotretinoin 20 mg daily led to complete clearance of skin lesions within 3 weeks. Assaying IgA serum reactivity to desmocollin 1, desmoglein 1, and desmoglein 3 as a valuable method for establishing the diagnosis and differentiating the 2 subtypes of IgA pemphigus. Isotretinoin was an effective drug in the treatment of subcorneal pustular dermatosis type of IgA pemphigus in this patient.

IgA pemphigus: a case report and its characteristic clinical features compared with subcorneal pustular dermatosis

We report a case of IgA pemphigus. A 35-year-old woman had vesiculopustular eruptions on her scalp, trunk, and extremities. Histologic examination showed a subcorneal pustule containing numerous neutrophils without acantholysis. Direct immunofluorescence revealed IgA deposits in the intercellular space throughout the epidermis, more intense in superficial layers and less intense in lower layers. The titer of circulating IgA antibodies was 1:160 in normal human skin as a substrate. Skin lesions responded to dapsone. The IgA autoantibody from this patient did not react with desmogleins or desmocollins when immunoblotting, enzyme-linked immunosorbent assay, or complement DNA transfection was used. We consider the characteristic clinical features that favor the diagnosis of IgA pemphigus rather than classic subcorneal pustular dermatosis as follows: (1) the lesions involve the scalp and/or face, and (2) the distribution of the lesions is more widespread.

Subcorneal pustular dermatosis type of IgA pemphigus: demonstration of autoantibodies to desmocollin-1 and clinical review

We describe a 40-year-old Japanese man with a 3-year history of vesiculopustular lesions resembling subcorneal pustular dermatosis. Histopathology showed subcorneal pustules containing a few acantholytic cells, and direct immunofluorescence disclosed IgA deposition in the intercellular space of the upper epidermis. Circulating IgA autoantibodies of very low titre were also demonstrated by indirect immunofluorescence. A novel cDNA transfection technique clearly detected IgA autoantibodies reactive with human desmocollin-1. Combined therapy with dapsone and etretinate improved the skin lesions. We review the clinical features of 49 patients in the literature who presented with vesiculopustular lesions and intraepidermal IgA deposition.