KID syndrome: The Keratitis- Ichthyosis-Deafness syndrome, an inherited disorder in which affected persons have gradual destruction of the cornea (keratitis) of the eye (possibly leading to blindness), localized areas of disfiguring reddish thickened skin (ichthyosis), deafness at birth, and thin or even absent scalp hair. Some patients have developed carcinoma of the tongue while others have subtle abnormalities of the nervous system. The cause of the KID syndrome is still a mystery.