Definition of Ichthyosis vulgaris:

Ichthyosis vulgaris is a common skin disorder passed down through families that leads to dry, scaly skin.

Causes, incidence, and risk factors:

Ichthyosis vulgaris is one of the most common of the inherited skin disorders. It may begin in early childhood, before age 4. In most cases one parent is affected -- and each child has a 50-50 chance of developing the condition.

The condition is often more noticeable in the winter. It may occur along with atopic dermatitis, keratosis pilaris (small bumps on the back of the arms), or other skin disorders.