Dry skin, also called xerosis, is a very common problem in modern life, affecting people of all ages, even infants. Scientists agree – because of a sharp decline in the Stratum corneum lipids (lipids are fats that are essential for the structure and function of living cells), especially the significant drop in ceramides (one of the more important structural components of the lipid barrier), by the time we reach age 40, our skin will almost certainly be dry and/or dehydrated.
However, some people experience the trials of a dry skin condition before they reach this time in their life. An increasingly stressful lifestyle coupled with continual exposure to the sun, wind and chemicals in the environment contribute to dry, dehydrated skin in people of all ages.
What is dry, dehydrated skin?
Dry skin, or slipped skin, generally refers to skin that is lacking oil, whereas dehydrated skin is characterised by the lack of moisture in the Stratum corneum, the outermost layer of the epidermis. Typically, cells that comprise the deepest layers of the epidermis have about 80% water content, while cells of the Stratum corneum are about 10% water. Anything below 10% is perceived as dehydrated.
Both dry and dehydrated skin is often irritated, inflamed and itchy, and it is generally worse in areas with relatively few sebaceous (oil) glands such as the arms, legs and torso, as well as the cheeks and eye area.
There is also a widespread misconception that dehydrated skin is the opposite of oily skin. “Dehydrated” refers to lack of moisture (not a lack of oil), while “oily” refers to levels of sebum or oil on skin. While adequate sebum does help maintain water levels on skin, oily skin can be dehydrated. Dehydrated skin may lack water only in the outermost layers of the epidermis while maintaining normal levels in the deeper layers.
Other symptoms of dry skin can include a feeling of tightness or tautness, especially after showering, bathing or swimming, skin that feels and looks rough rather than smooth, slight to severe flaking or scaling, fine lines, cracks that can sometimes bleed, and severe redness.