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.