Subcorneal pustular dermatosis type of IgA Pemphigus in a 35-year-old female: A case report

Introduction@#IgA pemphigus is a rare, distinct variant of Pemphigus characterized by vesiculopustular eruptions mediated by IgA autoantibodies targeting keratinocyte cell surface antigens, desmocollins 1-3 and sometimes desmogleins 1 and 3. Its classical features have been described in literature but atypical cases have also been documented. This report presents such case posing a diagnostic dilemma.@*Case Report@#A 35-year-old female presented with a 16-year history of intermittent eruptions of multiple hyperpigmented, annular and circinate, desquamating plaques and coalescing flaccid pustules on erythematous bases on the scalp, neck, trunk, and extremities. Histopathologic examination revealed subcorneal pustular dermatitis, and direct immunofluorescence was positive for granular intercellular IgG and IgA deposits in the epidermis. Antinuclear antibody test was negative and C3 level was normal. Antibody tests against desmogleins 1 and 3 were both negative. Topical potent corticosteroid therapy resulted in complete resolution of all lesions in three weeks.@*Conclusion@#Diagnostic dilemmas arise when laboratory results do not correlate with clinical findings. Findings of IgA autoantibodies in patients with pemphigus-like skin eruptions led to the diagnosis of subcorneal pustular dermatosis type of IgA pemphigus. Dapsone is the treatment of choice although topical potent corticosteroid alone may provide complete remission in some cases, avoiding the potential adverse effects of systemic therapy

A Case of Immunoglobulin A Pemphigus: Intraepidermal Neutrophilic Dermatosis Type / 대한피부과학회지

Immunoglobulin A (IgA) pemphigus is a rare variant of an autoimmune bullous disease with IgA antibodies. IgA pemphigus is divided into 2 major subtypes: the subcorneal pustular dermatosis (SPD) type and intraepidermal neutrophilic (IEN) dermatosis type. We documented a case of an 18-year-old woman with recurrent generalized blisters and pustules that were especially severe in the intertriginous areas. Some half-and-half blisters and coalesced pustules in an annular pattern with crusts were simultaneously observed. A biopsy specimen from one of the half-and-half blister lesions showed intraepidermal separation with multiple neutrophils. Direct immunofluorescence staining revealed lace-like intercellular deposition of IgA in the entire epidermis. IgA antibody deposits were also observed in the patient's serum. The eruptions cleared with systemic steroids and colchicine 0.6 mg for 1 week, and the patient remained in partial remission at the 8-month follow-up. Herein, we report a case of IEN-type IgA pemphigus, clinically mimicking SPD with half-and-half blisters.

IgG/IgA pemphigus reactive with desmoglein 1 with additional undetermined reactivity with epidermal basement membrane zone.

IgG/IgA pemphigus is an extremely rare subset of pemphigus, showing anti-keratinocyte cell surface antibodies of both IgG and IgA classes. Herein, we describe a unique case of IgG/IgA pemphigus with clinical features of edematous erythema and peripheral vesiculopustules. Histopathology showed the presence of subcorneal pustules and acantholytic blisters in the mid-epidermis with neutrophilic infiltration and eosinophilic spongiosis. Direct immunofluorescence of perilesional skin showed both IgG and IgA deposits to keratinocyte cell surfaces and unusual granular deposits of IgG, IgM, and C3 along basement membrane zone. On enzyme linked immunosorbent assay , the auto-antibodies were found to be reactive to desmoglein 1 antigen. Various clinical, histopathological, and immunological findings in our case overlapped with the features of IgA pemphigus, pemphigus herpetiformis, and pemphigus foliaceus. These findings indicate that IgG/IgA pemphigus may be a transitional form between IgA pemphigus and pemphigus herpetiformis, and thus provides insight into the pathogenicity of this rare disorder.