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.
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.