Dry Skin and Moisturizers
Although the environment affects moisture levels in the skin, people with eczema or very dry skin tend to have a barrier function that is not working properly. Repairing the barrier function and restoring its strength is necessary to treat very dry skin.
Why do I have dry skin?
Moisture levels in the skin are kept in balance by the barrier function. The rate at which water leaves the skin should be balanced by the rate at which water enters the skin to maintain balance. Water enters the skin from the dermis, the lower levels of the skin and slowly migrates to the surface of the skin called the epidermis. From there, water then evaporates. This process of natural water loss is called transepidermal water loss or TEWL. When the skin does not replace water at a fast enough rate to counterbalance this process, dry skin results.
Environmental factors like cold and dry air can increase the rate of this process by stripping away oil which helps insulate the skin by trapping moisture in the skin. This is why dryness is commonly a problem during the winter for many people. Those with dry skin tend to produce less oil which helps to prevent water loss, and has a tendency to react to external substances that the skin normally ignores.
How can moisturizers help me?
Moisturizers can help to reduce water loss through TEWL, as well as draw in additional water from the lower levels of the skin, and may also contain ingredients like ceramides which can help amplify the skin's ability to regulate moisture levels. For more information on ceramides, you check last month's article on ceramides. They also promote skin healing and reduce itchiness, and for those with very dry skin, it's an important part of daily skin care.
If you have a dry skin type, or suffer from a condition like eczema, stronger moisturizers that are designed specifically for dry skin should be used. These moisturizers are thicker, and often oil based. The lighter moisturizers are often preferred by those who don't like the greasy texture of heavy moisturizers, but those with very dry skin should not be using the lighter ones. A thick moisturizer, often branded intensive moisturizers, can help retain moisture and help the skin surface heal faster.