There are several causes of dry skin. The most common one is aging. The second most common cause is likely to be people’s washing regime, because the use of soaps, excessive showering or the use of certain shower gels can dry out the skin – and foot skin is no exception. Dry skin related to aging or over-washing is called “physiological dryness.” For people with that kind of dry skin, the use of emollients and moisturizers is very important in order to replenish lost water in the skin. But there are other possible triggers for dry skin. Fungal infections can be a cause as well as certain systemic conditions such as diabetes or thyroid problems. It is always important to find the cause of the dry feet.
The natural substance found in the upper layers of skin (epidermis) that attracts and binds water is urea.  When skin becomes dry it often lacks urea, a naturally occurring substance in the upper layers of the skin (epidermis), which attracts and binds water.