Hystrix-like keratosis with nail and joint-involvement: a new genodermatosis?

BACKGROUND AND

OBJECTIVE

We describe a familial disorder featuring hystrix-like keratosis, thickened nails and plantar hyperkeratosis. The index patient, a 10-year-old girl, suffered also from joint laxity and had long fingers, while in her mother only the typical skin lesions were observed.

METHODS AND

RESULTS

Histologic examination of the spiny hyperkeratoses in the index patient showed parakeratosis with marked cornoid lamella. On electron microscopy the keratinocytes exhibited intracellular vacuolization and aggregated tonofilaments, but no concentric shell formation.

CONCLUSION

The striking skin lesions present in the 2 cases can be distinguished from other forms of hystrix-like hyperkeratoses such as nevus corniculatus or multiple digitate hyperkeratoses and hence may represent a new autosomal dominant genodermatosis.