Uncomfortable, Itchy, Scaly, Red. These are all words used to describe dry skin, a common problem among all ages, races, and genders. There are two main causes of dry skin, a weakness in the keratin or a breakdown in the lipids. Keratin needs water to keep it healthy. Lipids work as the mortar that bonds skin cells and helps to form a tight, protective barrier. By using the right moisturizers, you can trap water in the skin and even repair the damaged lipid barrier.