Ichthyosis is a group of inherited disorders characterized by excessively scaly and dry skin.
In various forms of ichthyosis, certain proteins that are important in producing proper skin adhesion are missing. This causes water to be lost through the skin.
Ichthyosis is one of the most common inherited skin conditions. It may begin in a child as young as 4 years old. It usually disappears during adulthood, and may reappear when a person becomes elderly.