Pemphigus herpetiformis: analysis of the autoantibody profile during the disease course with changes in the clinical phenotype

BACKGROUND

Pemphigus herpetiformis (PH) is a rare dapsone-responsive variant of pemphigus, characterized by annular and vesiculopustular cutaneous lesions. Most PH serum samples contain autoantibodies against desmoglein (Dsg)1, but not Dsg3, and the presence of the latter is almost invariably associated with mucosal involvement, as predicted based on the 'Dsg compensation theory'.

METHODS

We describe a patient with features characteristic of PH with histologically eosinophilic spongiosis who repeatedly tested positive for anti-Dsg3 but not anti-Dsg1 autoantibodies by ELISA. To investigate whether the peculiar clinical phenotype was due to a distinct immunological profile, the patient's serum was tested by ELISA and immunoblotting using recombinant forms of Dsg3.

RESULTS

Serum samples were found to have low and high reactivity against the EC1 and the EC4 domains of Dsg3, respectively, whereas the autoantibodies belonged predominantly to the IgG1 and IgG4 subclasses. The overall immunological profile was typical of pemphigus vulgaris. The patient finally developed isolated oral erosions 22 months after initial presentation, without significant changes in the autoantibody profile and of the targeted antigenic sites.

CONCLUSIONS

Our patient presented features characteristic of PH. Although circulating anti-Dsg3 antibodies were present, the patient had only cutaneous involvement for a long period. Our findings indicate that the proposed Dsg compensation theory cannot always explain the clinical phenotype, changes in which may occur without apparent modification of the autoantibody profile and antibody specificity. Hence, additional factors, such as Fcgamma-dependent neutrophil activation, may critically affect the clinical presentation of pemphigus.

Acquired Melanocytic Naevus in Childhood Vulval Pemphigoid

BACKGROUND

Eruptive epidermolysis bullosa (EB) naevi comprise a subset of melanocytic naevi with atypical features that characteristically occur in areas of former blistering in patients suffering from hereditary EB.

OBSERVATION

The case is reported of a girl who presented with pruritus, blistering and erosions of the vulval region. Clinical and immunopathological features were consistent with the diagnosis of childhood vulval pemphigoid. In the course of the disease, she developed an atypical melanocytic naevus on the left labium at a site of former blistering. Although its clinical and dermoscopic features resembled malignant melanoma, the lesion completely regressed clinically during the 24-month follow-up.

CONCLUSION

This is the first report describing the development of a melanocytic naevus at sites of blistering in an auto-immune subepidermal blistering disease in childhood. Our observation extends the spectrum of disorders, in addition to the group of congenital EB, in which 'eruptive' atypical melanocytic naevi may occur. Knowledge of this complication is important for appropriate management and follow-up and to avoid radical surgery.

Comparative analysis of the expression of ERBIN and Erb-B2 in normal human skin and cutaneous carcinomas

BACKGROUND

ERBIN is a binding partner of Erb-B2, an orphan receptor within the Erb-B family critically involved in the regulation of cell growth and differentiation. Although its function remains unclear, ERBIN is thought to affect the polarity of epithelial cells and cell growth via the Ras signalling pathway.

OBJECTIVES

To examine and compare the tissue distribution and the expression levels of ERBIN and Erb-B2 in normal skin and in cutaneous carcinomas.

METHODS

Fifteen cases of basal cell carcinoma (BCC), 12 cases of squamous cell carcinoma (SCC) and five cases of keratoacanthoma (KA) were analysed by immunohistochemistry on paraffin-embedded sections using anti-ERBIN and anti-Erb-B2 antibodies.

RESULTS

ERBIN and Erb-B2 had a similar distribution in normal human skin. They were primarily localized at the plasma membrane in differentiated keratinocytes and in duct cells from eccrine glands, whereas they were localized diffusely in the cytoplasma of basal keratinocytes. In both SCC and KA the subcellular distribution of ERBIN and Erb-B2 remained unchanged, whereas both proteins were redistributed from the plasma membrane into cytosolic aggregates in BCC.

CONCLUSIONS

The subcellular localization of ERBIN in normal human skin is similar to that of Erb-B2 and varies with cell differentiation. Based on our findings and on the biological activities of Erb-B2, it is conceivable that disturbed expression or functioning of ERBIN and Erb-B2 is implicated in the development of the malignant phenotype of BCC.

Localized Childhood Vulval Pemphigoid Treated with Tacrolimus Ointment

BACKGROUND

Localized vulval childhood pemphigoid is a rare variant within the pemphigoid group. Although its prognosis seems favorable, the best therapeutic strategy remains unclear.

OBSERVATION

We here describe the case of an 8-year-old girl presenting with a 5-year history of relapsing vulval pain and lesions suggestive of lichen sclerosus. Clinical features, light microscopy and direct immunofluorescence microscopy were consistent with vulval cicatricial pemphigoid, although the autoantigen(s) involved could not be characterized. Her disease responded to treatment with topical tacrolimus ointment 0.1% within 3 months without any evidence for disease activity, except for slight residual scarring. After 12 months, her treatment was stopped without relapse.

CONCLUSION

This observation suggests that in this rare immune-mediated blistering disease topical tacrolimus is an interesting therapeutic option without the adverse effects associated with topical steroids.