Epidermal nevus syndromes: clinical findings in 35 patients.

Of the patients with epidermal nevi, 10-18% may have disorders of the eye, nervous, and musculoskeletal systems. A predisposition to malignant neoplasms in ectodermal and mesodermal structures may also be found. There are six different epidermal nevus syndromes described so far: Proteus, congenital hemidysplasia with ichthyosiform nevus and limb defect syndrome, phakomatosis pigmentokeratotica, sebaceous nevus, Becker nevus, and nevus comedonicus. Thirty-five patients with epidermal nevus syndrome seen at the National Institute of Pediatrics in Mexico City during a 31-year period are described. This syndrome represented 7.9% of 443 patients with epidermal nevi; its relative frequency was 1 case per 11,928 pediatric patients and 1 case per 1080 dermatologic patients. Nine epidermal nevus syndrome patients (26%) had Proteus syndrome. Sebaceous nevus syndrome was found in six patients (17%), while the nevus comedonicus syndrome was found in three (8%). Two patients were diagnosed with phakomatosis pigmentokeratotica and one patient with congenital hemidysplasia with ichthyosiform nevus and limb defect syndrome. This is the first report of phakomatosis pigmentokeratotica and congenital hemidysplasia with ichthyosiform nevus and limb defect syndrome in Mexican patients. One patient had an inflammatory linear verrucous epidermal nevus with systemic involvement. Thirteen patients (37%) had keratinocytic nevi with systemic involvement. We propose the keratinocytic nevus syndrome to be defined as the association of a keratinocytic nevus with neuronal migration and/or musculoskeletal disorders in addition to a higher risk for mesodermal neoplasms.