This is a disorder of keratinization, most often seen alone but it can be associated with AD. It is an autosomal dominant inherited disorder characterized by varying degrees of dryness, scaling, and exfoliation of skin. The scales found on the scalp are quite small, but increase in size in a caudal direction over the rest of the body. On the legs they are large and have a "pasted-on" appearance.

2b. Kerotosis pilaris

This is a common autosomal dominant trait, frequently associated with AD. There is follicular hyperkeratosis which is seen on the extensor surfaces of the arms and legs, and occasionally on the face as well. It gives the skin the appearance of permanent "goose bumps" and a rough texture.

2c. Palmar hyperlinearity

Frequently the hands of younger patients will appear "old-looking"--it is always a surprise to see a 1-year old with the hands of a 99-year old! This appearance is due to hyperlinearity.