Ito hypomelanosis (Monarch Disease Ontology identifier MONDO_0010302) can be described as follows. Hypomelanosis of Ito (HI) is a multisystemic neurocutaneous condition with hypopigmented skin lesions along the Blaschko lines. Also known as: Hypomelanosis of Ito, Incontinentia pigmenti type 1, hi syndrome, hypomelanosis of Ito, pigmentary mosaicism, Ito type.