Hypomelanosis of Ito (HMI) is a very rare birth defect that causes unusual patches of light-colored (hypopigmented) skin and may be associated with eye, nervous system, and skeletal problems.
Health care providers do not know the exact cause of HMI, but they believe it may involve a genetic condition called mosaicism. It is twice as common in girls as in boys.
Skin symptoms are most often visible by the time a child is about 2 years old.
Other symptoms develop as the child grows, and may include:
Ultraviolet light (Wood lamp) examination of the skin lesions may help confirm the diagnosis.
Tests that may be done include any of the following:
There is no treatment for the skin patches. Cosmetics or clothing may be used to cover the patches. Seizures, scoliosis, and other problems are treated as needed.
Outlook depends on the type and severity of symptoms that develop. In most cases, skin color eventually turns to normal.
Problems that may result from HMI include:
Call your provider if your child has an unusual pattern of the color of the skin. However, any unusual patterns are likely to have another cause than HMI.
Reviewed By: Michael Lehrer, MD, Clinical Associate Professor, Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.