According to Healthline, dry skin may be a symptom of another disease. So always be sure to get evaluated properly for your symptoms. Such as Allergic dermatitis, Atopic dermatitis, contact dermatitis, and Seborrheic dermatitis amongst many other non-skin related diseases. All of these diseases result in severely dry skin.
Environmental factors also can create dry skin. Cold, harsh weather draws fluid and water from the skin, leaving behind a dry environment. It causes skin to flake and become irritated at times. Sun tanning may also leave skin damaged, and dry and flaky.
It may be a genetic factor. Some people are predisposed genetically to oily skin, it is the same effect for dry skin and in-between types of skin.
Dehydration may also be a factor. When you do not take in enough fluids for your body to operate fully and properly, the skin suffers and is not well lubricated to do its job.
It could also be attributed to using the wrong type of product for your skin. If you are using a product that is meant for oily skin, it will dry out your skin even faster. It could also be the fact that you are using too much of the product, or an incorrect technique such as a wash cloth, or exfoliating too often.
All of these can contribute to dry skin as a condition. But it may be other factors not discussed in this article. Before seeking treatment please consult with your physician for your specific needs.