Normal skin owes its soft, supple texture to its water content. For skin to feel soft, pliable and "normal," its top layer must contain a minimum of ten percent water and ideally between 20 percent and 35 percent. To help protect the outer layer of skin from abnormal water loss, the skin's sebaceous glands produce an oily substance called sebum. Sebum is a complex mixture of fatty acids, sugars, waxes and other natural chemicals that form a protective barrier against water evaporation. If some internal or external factor depletes the skin's layer of sebum, the skin loses water and feels dry. If environmental factors overwhelm the ability of sebum to prevent water loss, the skin will shrivel and crack.
Dry skin is an extremely common problem for people of all ages. However, as we age, the skin loses moisture and may become dry, dull, flaky, and scaly. Excessive dryness can lead to severe itching and eczema. Dry skin can also exacerbate underlying skin conditions such as atopic dermatitis and psoriasis.
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