Lichenification is the thickening and hardening of skin where it is constantly rubbed or scratched. The skin becomes leathery, and the normal lines in the skin become exaggerated, giving it a barklike appearance.
Lichenification often occurs in people with skin conditions that cause itching, such as atopic dermatitis (eczema). However, it can also develop in people with otherwise healthy skin.
WebMD Medical Reference from Healthwise