Causes of Dry Skin

Dry skin is a very common condition. Dry skin is one of the most common skin abnormalities. Although certain individuals are more susceptible to dry skin, the condition can affect anyone, regardless of age, gender, or skin type.

Dry skin occurs when the skin’s outer layer (the stratum corneum) is depleted of water. The skin’s outer layer consists of dead, flattened cells that gradually move toward the skin’s surface and slough off. Called the stratum corneum, the outer layer has an important protective role. When this layer is well-moistened, it minimizes water loss through the skin and helps keep out irritants, allergens, and germs. However, when the stratum corneum dries out, it loses its protective function. This allows greater water loss, leaving the skin vulnerable to environmental factors.

Under normal conditions, the stratum corneum has a water content of 10% to 30%. This water gives the skin its soft, smooth, and flexible texture. The water comes from the atmosphere, the underlying layers of skin, and sweat. Oil produced by skin glands and fatty substances produced by skin cells act as natural moisturizers, allowing the stratum corneum to seal in water.

We continuously lose water from the skin’s surface by evaporation. Under normal conditions, the rate of loss is slow, and the water is adequately replaced. Characteristic signs and symptoms of dry skin occur when the water loss exceeds the water replacement, and the stratum corneum’s water content falls below 10%.

Although most cases of dry skin respond well to self-care, some cases require professional medical care. Mild-to-moderate cases of dry skin usually respond well to self-care measures and over-the-counter products. However, professional medical care is needed for severe dry skin, dry skin accompanied by other symptoms, and dry skin that persists despite self-care measures. These patterns of dry skin may signal the presence of other skin conditions, other medical conditions, or drug side effects. Persistent dry skin can lead to complications such as inflamed skin (dermatitis) and infection. A primary care provider can treat some cases of dry skin, but more complex cases of dry skin usually require treatment by a dermatologist.

Dry Skin Causes
Any factor that damages the stratum corneum can interfere with its barrier function and lead to dry skin. These factors include long, hot showers and cold, dry air, detergents and solvents, or chafing and scrubbing. When the stratum corneum is damaged, water moves more freely towards the surface of your skin where it evaporates, causing your skin’s water content to fall.

Abnormal loss of skin surface cells may also play a role in dry skin. Normally, cells lost from the skin’s surface are shed individually and unnoticeably. However, sometimes the cells stick together and resist shedding. As a result, the stratum corneum thickens. When the cells are lost, they are lost as large visible sheets called scales.

Some people inherit a tendency for dry skin. The moisture level of the skin is partly determined by genetics. Under identical conditions, different people will have normal, oily, or dry skin. Fair-skinned individuals seem to be more prone to dry skin than people with darker complexions.

The normal changes associated with aging often lead to dry skin. With increasing age, the skin’s ability to produce sweat, oil, and other fatty substances diminishes. The skin cells also divide more slowly, and the skin thins and takes longer to repair. As a result, the water content of skin is reduced in older adults. This age-related dry skin is usually more pronounced in women than in men.

Extremely dry skin is called xerosis (ze-ROW-sis).

 Extremely dry skin can be a warning sign of a skin problem called dermatitis (derm-muh-TIE-tis).

Dermatitis means inflammation of the skin. It can cause an itchy rash or patches of dry irritated skin. The earlier dermatitis is diagnosed and treated the better, because often without treatment, dermatitis gets worse.