Epidermal nevus syndrome (ENS) refers to an already congenitally manifested syndrome in which epidermal nevi are associated with various developmental disorders of the skeletal, nervous, genitourinary, and cardiovascular system and the eyes. A defective morphogenesis with hyperplasia of epidermal structures in circumscribed areas of the skin is the cause of epidermal nevi, most of which are present at birth.
Neurological symptoms occur in about 50 percent of patients. These are characterized by mental retardation, epilepsy, malformations of the cerebral veins, bovine atrophy, spastic paresis and dilated lateral ventricles.
About one-third of those affected have ophthalmological signs including colobomas of the iris, eyelids and retina, as well as conjunctival lipodermoids, choristomas, central blindness, corneal erosion, cataract, and micro-, macro-, and anophthalmia.