Ichthyosis

**Definition:** Any of several generalized skin disorders characterized by dryness, roughness, and scaliness, due to hypertrophy of the stratum corneum epidermis. Most are genetic, but some are acquired, developing in association with other systemic disease or genetic syndrome.

**Tree numbers:** - C16.131.831.512 - C16.614.492 - C17.800.428.333 - C17.800.804.512