Clinical, histopathological and immunological distinction in two cases of IgA pemphigus

Papulosquamous annular diseases

Papulosquamous diseases represent a commonly encountered group of cutaneous disorders in dermatology. Lesions can present with papules and plaques in various configurations, including annular forms. Some of these disorders are expected to appear in annular configurations, such as pityriasis rosea and subcorneal pustular dermatosis. Others may either begin as or even progress to annular configurations, including psoriasis vulgaris, seborrheic dermatitis, and nummular dermatitis. We have reviewed common papulosquamous diseases that can present with annular lesions, which includes psoriasis vulgaris, pityriasis rosea, subcorneal pustular dermatosis, contact dermatitis, seborrheic dermatitis, and nummular dermatitis. For each disorder, we have discussed the details of presentation and differential diseases to be considered.

Anti-Desmocollin Autoantibodies in Autoimmune Blistering Diseases

The presence of anti-desmocollin (Dsc) antibodies is rarely described in autoimmune blistering diseases patients. Moreover, several clinical phenotypes of pemphigus may be associated with these antibodies. In this review we analyze clinicopathological, immunologic and outcome features of anti-Dsc autoimmune blistering diseases patients, to improve their diagnosis and management. We conducted a systematic search of PubMed and Embase (1990-present) for studies reporting cases of autoimmune blistering diseases with anti-Dsc antibodies. We classified the selected patients as patients with exclusively anti-Dsc autoantibodies, and patients with anti-Dsc and other autoantibodies. Of 93 cases with anti-Dsc autoantibodies included, 38 (41%) had exclusively these antibodies. Only 18% of patients presented with the typical clinicopathological phenotype of pemphigus vulgaris or pemphigus foliaceous. Mucosal involvement was seen in approximately half of the patients. Up to 18% of cases were associated with neoplasms. Acantholysis was described in 54% of cases with histopathological information. Treatments and outcomes vary in the different clinical phenotypes. The presence of anti-Dsc antibodies must be suspected mainly in those patients with either atypical pemphigus, in special with clinical pustules, or in cases showing intraepithelial or dermal neutrophilic/eosinophilic infiltrate on histological examination and dual pattern by direct immunofluorescence examination.

Advances in the diagnosis of autoimmune bullous dermatoses

Autoimmune bullous dermatoses are defined by autoantibodies directed against adhesion proteins in the epidermis or basement membrane zone, resulting in blister formation on the skin and mucosa. Diagnosis depends on lesional biopsy for histopathology and perilesional biopsy for direct immunofluorescence. Additional diagnostic methods include indirect immunofluorescence, enzyme-linked immunosorbent assay, and immunoblot (Western blot), which may be selected in specific clinical scenarios due to improved sensitivity and/or specificity. This contribution reviews the available evidence supporting the use of each method to provide a practical reference for clinicians when diagnosing autoimmune bullous disorders. Techniques and cost are reviewed, and newer diagnostic techniques with potential for clinical application are.

Imatinib-induced IgA Pemphigus: Subcorneal Pustular Dermatosis Type

Imatinib mesylate, a tyrosine kinase inhibitor, is commonly used in the treatment of chronic myeloid leukemia. IgA pemphigus is a rare bullous dermatosis caused by IgA autoantibodies. Clinical manifestations include localized or generalized itchy blisters and pustules. Drug-induced IgA pemphigus has been rarely reported in the literature till date. Here, we report one such rare case caused by imatinib which responded poorly to oral prednisolone but showed excellent response to tablet dapsone.

IgA Pemphigus in a Child – a Case Report

IgA pemphigus (IGAP) is a rare autoimmune bullous disease characterized by IgA deposits on keratinocyte cell surfaces. The IGAP is classified into: 1) subcorneal pustular dermatosis (SPD) type, and 2) intraepidermal neutrophilic (IEN) IgA dermatosis type. So far, only 9 children with IGAP have been described in the literature, of whom only 3 with SPD type. We report a 3-year-old boy with SPD type of IGAP. Clinically, he presented with pruritic vesicles, pustules and erosions on the face, trunk, groin area, and extremities. Histopathology showed subcorneal pustules containing a few acantholytic cells. Direct immunofluorescence (DIF) test of Tzanck smear showed intercellular IgA deposits on the surface of the groups of epidermal cells. Oral dapsone and prednisone induced remission after two weeks; the treatment was discontinued 11 months later, and complete remission was achieved during 19 months without any treatment. Direct immunofluorescence of Tzanck smear is a simple, sensitive, rapid and non-aggressive test, very suitable for the diagnosis of IGAP in children.

Subcorneal Pustular Dermatosis: A Review of 30 Years of Progress

Subcorneal pustular dermatosis (SPD), also known as Sneddon-Wilkinson disease, is a rare, benign yet relapsing pustular dermatosis. Its incidence and prevalence have not been well studied. It characteristically presents as hypopyon pustules on the trunk and intertriginous areas of the body. SPD is similar to two other disease entities. Both SPD-type immunoglobulin (Ig)-A pemphigus and annular pustular psoriasis clinically and histologically present similarly to SPD. Immunologic studies separate SPD-type IgA pemphigus from SPD and pustular psoriasis. However, there is still an unclear designation as to whether SPD is its own entity distinct from pustular psoriasis, as the once thought characteristic histologic picture of psoriasis does not hold true for pustular psoriasis. SPD has been reported to occur in association with several neoplastic, immunologic, and inflammatory conditions. Dapsone remains the first-line treatment for SPD, although dapsone-resistant cases have been increasingly reported. Other therapies have been used singly or as adjunctive therapy with success, such as corticosteroids, immunosuppressive agents, tumor necrosis factor inhibitors, and ultraviolet light therapy. This article provides a review of the last 30 years of available literature, with a focus on successful treatment options and a suggestion for reappraisal of the classification of SPD.

Two Brazilian Cases of IgA Pemphigus

IgA pemphigus is a rare, neutrophilic, acantholytic skin disorder with approximately 70 cases described in the literature. We report two patients with the subcorneal pustular dermatosis (SPD) type of IgA pemphigus. Initially, both patients were misdiagnosed as subcorneal pustular dermatosis of Sneddon and Wilkinson. The correct diagnosis was only made after detecting intercellular IgA depositions in the epidermis by direct immunofluorescence. Immunoblotting (IB) of normal human epidermal extracts, performed on both sera, was negative for Dsg 1, Dsg 3, BP 230, BP 180, 210 kDa envoplakin, and 190 kDa periplakin. ELISA for desmogleins (Dsg 1 and Dsg 3) showed that neither of the cases had IgA antibodies to Dsg. The c-DNA transfection test for desmocollins (Dsc) revealed that the IgA antibodies of both patients reacted with desmocollin 1. This result supports the hypothesis that the autoantigen in SPD type IgA pemphigus is desmocollin 1.

Molecular diagnosis in autoimmune skin blistering conditions

Blister formation in skin and mucous membranes results from a loss of cell-cell or cell-matrix adhesion and is a common outcome of pathological events in a variety of conditions, including autoimmune and genetic diseases, viral and bacterial infections, or injury by physical and chemical factors. Autoantibodies against structural components maintaining cell-cell and cell-matrix adhesion induce tissue damage in autoimmune blistering diseases. Detection of these autoantibodies either tissue-bound or circulating in serum is essential to diagnose the autoimmune nature of disease. Various immunofluorescence methods as well as molecular immunoassays, including enzyme-linked immunosorbent assay and immunoblotting, belong to the modern diagnostic algorithms for these disorders. There is still a considerable need to increase awareness of the rare autoimmune blistering diseases, which often show a severe, chronic-relapsing course, among physicians and the public. This review article describes the immunopathological features of autoimmune bullous diseases and the molecular immunoassays currently available for their diagnosis and monitoring.

[Efficacy of acitretin in IgA pemphigus]

BACKGROUND

IgA pemphigus is a particular entity among autoimmune blistering intraepidermal diseases. IgA pemphigus is subdivided into two types: intraepidermal neutrophilic IgA dermatosis and subcorneal pustular dermatosis.

PATIENTS AND METHODS

We report the case of an 82-year-old woman with intraepidermal neutrophilic IgA pemphigus associated with IgA gammopathy. The histopathological findings were unusual, with numerous large subcorneal pustules, a few pustules in the stratum spinosum, and basal IgA deposition. A favourable outcome was achieved with acitretin.

DISCUSSION

This observation is significant in that it highlights the difficulty of classification of IgA pemphigus, which is currently based on clinical and histopathological findings. There is currently no therapeutic consensus attitude but simply a set of empirical data.

Autoinflammatory pustular neutrophilic diseases

This article provides a new categorization of inflammatory pustular dermatoses in the context of recent genetic and biological insights. Monogenic diseases with pustular phenotypes are discussed, including deficiency of interleukin 1 receptor antagonist, deficiency of the interleukin 36 receptor antagonist, CARD14-associated pustular psoriasis, and pyogenic arthritis, pyoderma gangrenosum, and acne. How these new genetic advancements may inform how previously described pustular diseases are viewed, including pustular psoriasis and its clinical variants, with a focus on historical classification by clinical phenotype, is also discussed.

A unique case of intra-epidermal neutrophilic dermatosis-type IgA pemphigus presenting with subcorneal pustules

BACKGROUND

While subcorneal pustular dermatosis-type IgA pemphigus shows subcorneal pustules, intra-epidermal neutrophilic dermatosis (IEN)-type IgA pemphigus is characterised by pustule formation throughout the entire epidermis.

OBJECTIVE

We analysed an unusual case of IEN-type IgA pemphigus showing subcorneal pustules.

METHODS

Indirect immunofluorescence, immunoblot analysis, auto-antibody-specific ELISAs, and double-labelling immuno-electron microscopy were performed.

RESULTS

IgA antibodies bound to the surface of keratinocytes distributed throughout the epidermis were detected by indirect immunofluorescence. IgA from the patient's serum failed to react with COS-7 cells expressing desmocollins (Dsc) 1, 2 or 3. IgG or IgA antibodies against desmogleins 1 and 3 were also found to be absent by ELISA. Double-labelling immuno-electron microscopy using an anti-Dsc monoclonal antibody showed localisation in the desmosomes, while IgA from the patient's serum was found in non-desmosomal regions.

CONCLUSION

The patient in the present study most likely suffers from IEN-type IgA pemphigus.

IgA pemphigus--occurrence of anti-desmocollin 1 and anti-desmoglein 1 antibody reactivity in an individual patient

BACKGROUND

IgA pemphigus is a rare pustular autoimmune disease with exclusive IgA anti-keratinocyte cell surface antibody reactivity. Two subtypes have been discerned: in the subcorneal pustular dermatosis type, desmocollin 1 has been identified as a targeted autoantigen, while in few cases of the intraepidermal neutrophilic type, IgA anti-desmoglein 1 or IgA anti-desmoglein 3 reactivity has been demonstrated.

PATIENTS AND METHODS

A 48-year-old white male presented with generalized large confluent pustules. Skin pathology was assessed by histology and direct immunofluorescence analysis. IgG/IgA autoantibodies against desmoglein 1/3 and desmocollin 1 were measured by ELISA and indirect immunofluorescence using desmocollin 1 cDNA-transfected COS7 cells, respectively.

RESULTS

Histopathology revealed subcorneal pustules and direct immunofluorescence microscopy exclusively showed in vivo bound IgA with an intercellular pattern in the epidermis. Desmocollin 1 was identified as a target of IgA autoantibodies by indirect immunofluorescence microscopy utilizing desmocollin 1 cDNA-transfected COS7 cells. In addition, IgA anti-desmoglein 1 reactivity was demonstrated by ELISA. Neither IgA anti-desmoglein 3 nor IgG anti-desmoglein 1/3 autoantibodies were present.

CONCLUSIONS

Both desmocollin 1 and desmoglein 1 were autoantigens in this patient with IgA pemphigus and a distinct clinical presentation. To our knowledge, this is the first IgA pemphigus case with dual autoantibody reactivity.