Hypomelanosis ito

Abstract

Hypomelanisis Ito (HI) is a neurocutaneous disorder characterised by hypopigmented skin lesions appearing on any body part. Skin lesions are related to various extracutaneous manifestations. The central nervous system (CNS) and the musculoskeletal system are most frequently involved. The clinical course is very variable. Of neurocutaneous disorders it is the fourth most prevalent, most cases being sporadic. We present five children fulfilling HI diagnostic criteria, 3 males and 2 females, all with CNS affection. One female with a severe clinical course had bilateral hypopigmented lesions, refractory epilepsy, pathologic EEG, mild mental retardation (MR), hypotonia and clumsiness. The oldest female patient had unilateral skin lesions, normal neurological and intellectual development and the first seizure at the age of 14 years. Four children had bilateral hypopigmented skin lesions. One male patient had mild MR and the second one had sensorineural deafness with febrile seizures and normal EEG. One girl had pathological EEG without seizures. Two patients had normal brain MRI findings, one had enlarged cistetrna magna (cerebellomedullary cistern). The girl with the most severe clinical course had the following brain MRI changes: mildly enlarged subarachnoidal spaces over the convexities and attenuated grey-white matter difference. All the patients had macrocrania. One girl had other musculoskeletal abnormalities. Skin biopsies were performed in two patients at the hypopigmented sites, showing normal dermis and epidermis hystologically. At the basal layer, using Fontana stains, we discovered spots with reduced or no melanin.