Woolly-hair nevus: report of a case associated with a verrucous epidermal nevus in the same area

Topical everolimus therapy for epidermal nevi associated with woolly hair nevus in a patient with a mosaic HRAS mutation

A patient with woolly hair nevus syndrome, presented with epidermal facial nevi by the age of 12 years. Despite transient improvement with topical 1% sirolimus cream, the facial nevus grew larger. The patient was then treated with topical 1% everolimus cream resulting in a reduction in the size of the nevus. This case highlights a novel use of topical 1% everolimus cream, which previously has not been used to treat epidermal nevi.

Mosaicism in genodermatoses

Genodermatoses are inherited disorders presenting with cutaneous manifestations with or without the involvement of other systems. The majority of these disorders, particularly in cases that present with a cutaneous patterning, may be explained in the context of genetic mosaicism. Despite the barriers to the genetic analysis of mosaic disorders, next-generation sequencing has led to a substantial progress in understanding their pathogenesis, which has significant implications for the clinical management and genetic counseling. Advances in paired and deep sequencing technologies in particular have made the study of mosaic disorders more feasible. In this review, we provide an overview of genetic mosaicism as well as mosaic cutaneous disorders and the techniques required to study them.

Angora hair nevus. A further case of an unusual epidermal nevus representing a hallmark of angora hair nevus syndrome

BACKGROUND

The association of Blaschko lines with genetic mosaicism has lead to the concept that this pattern represents the manifestation of genetically abnormal skin tissue contrasting with the genetically normal skin. Various mosaic defects affecting not only the skin but also extracutaneous tissues have lead to the description of different types of epidermal nevus syndromes. We present a further case of an unusual organoid epidermal nevus characterized by depigmented hypertrichosis.

MAIN OBSERVATIONS

We describe a 2-year-old boy with a systematized angora hair nevus being characterized by bands covered with soft white hair arranged along Blaschko's lines, involving the scalp, face, and trunk. A biopsy obtained from a scalp lesion showed mild epidermal acanthosis and increased pigmentation of the basal layer. Trichoscopy the affected scalp hair demonstrated fine light coloured shafts. The boy had slight macrocephaly and body asymmetry, a sacral pit, and koilonychia of the big toes.

CONCLUSIONS

The angora hair nevus is a peculiar type of organoid epidermal nevus, representing the cutaneous hallmark of a distinctive syndrome, the angora hair nevus syndrome (Schauder syndrome). In cases of epidermal nevi showing hypertrichosis, this unusual entity should be borne in mind for differential diagnosis.

Epidermal nevus syndrome: association with central precocious puberty and woolly hair nevus

The epidermal nevus syndrome is characterized by the association of epidermal nevi with abnormalities of the skin, skeletal system, central nervous system, eyes, and cardiovascular system, as well as with malignant conditions. We describe a 2-year-old girl with an extensive epidermal nevus involving the left side of the body (nevus unius lateris) and associated with a woolly hair nevus on the left parietal area of the scalp and multiple acquired melanocytic nevi. Idiopathic central precocious puberty characterized by premature breast and public hair development and advanced bone age developed at the age of 20 months. A sharp increase in serum gonadotropins after a luteinizing hormone releasing hormone (LHRH) stimulation test confirmed the presence of central precocious puberty. This is the third reported case of precocious puberty associated with the epidermal nevus syndrome.