[Multiple woolly hair nevi with linear epidermal nevus and persistent pupillary membrane]

The woolly hair nevus is a very rare disease that only occurs sporadically. So far, approximately 48 patients with woolly hair nevus have been described in the world literature. Both sexes are equally affected. Mostly, the dermatosis manifests itself from birth or within the first 2 years of life. Up to 5 circumscribed areas with clearly lighter curly hairs can be observed. About 50% of the patients present a linear epidermal nevus at the same time. Microscopically, the hair shaft diameter of the woolly hair is significantly reduced. Next to oval structures the cross-sections of the hair often show triangular and irregular forms. Furthermore, pili canaliculi and pili torti as well as circumscribed cuticula defects can be observed. We present a 5-year-old boy, who manifested 4 woolly hair nevi on the capillitium in the 9th month of life. From the 2nd year of life onwards he developed a linear epidermal nevus. The ophthalmological examination showed a persistent pupillary membrane. Based on this case and a bibliographical overview, the light and electron microscopical peculiarities are presented.