desquamation

desquamation, peeling or shedding of the superficial portion of the epidermis, or outermost layer of the skin. The epidermis consists of five distinct sublayers, including the bottommost, basal layer, which constantly produces new skin cells that push up to the skin surface, and the outermost, stratum corneum, the tough surface layer where skin cells ultimately die and slough off. Dead skin cells on the surface of the body are shed and replaced daily via desquamation, which helps maintain a healthy and well-functioning covering of skin. However, increases in the quantity of skin cells shed or in the rate of desquamation may be a symptom of a specific condition or disease. In such cases, skin dryness, itching, inflammation, irritation, or rash may occur in conjunction with desquamation.

Dead skin cells typically come off on their own but may also be washed or scrubbed off, through exfoliation, for example, or may be rubbed off by friction, which can occur through movement and wearing clothing. Increased desquamation, on the other hand, is most often associated with skin damage, such as that incurred via mild sunburn or windburn or via burning from skin exposure to fire, chemicals, electricity, or radiation.

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Desquamation may also occur in association with the use of certain medications and with some diseases, such as autoimmune disease and cancer. For example, some acne and antiaging treatments, such as retinol creams, cause dry skin and skin peeling. Also causing desquamation are cancer treatments, especially radiation therapy, which may produce a so-called moist reaction in the targeted area of skin, leading to wet sores, ulcers, and peeling. Likewise, chemotherapy may cause skin to become dry, red, itchy, and flaky. Disorders of the immune system, including psoriasis and pemphigus, involve symptoms of peeling skin. Desquamation may also be a symptom of chronic dermatitis (also known as eczema), which causes inflammation of the skin.

Rare, potentially life-threatening conditions known as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are other causes of desquamation. In some patients, SJS and TEN are due to allergic reactions to medications; in others, they result from bacterial infections. Desquamation is a symptom of various bacterial infections, including impetigo, scarlet fever, and toxic shock syndrome (TSS), all of which are caused by certain types of Streptococcus bacteria. Both impetigo and TSS may also be caused by Staphylococcus aureus bacteria. Likewise, several different fungal infections may cause desquamation, including ringworm infections such as tinea pedis (athlete’s foot), tinea cruris (jock itch), tinea capitis (scalp ringworm), and tinea corporis (body ringworm).

Acral peeling skin syndrome is a genetic skin disorder in which the top layer of skin painlessly peels off. Most desquamation is on the hands and feet, but it may also occur on the arms and legs. The disorder may begin in infancy, later in childhood, or in adulthood. Kawasaki syndrome, in which the skin on the palms of the hands and the soles of the feet is red and swollen and skin on the fingers and toes peels, may also have a genetic association with desquamation. The exact cause of the syndrome is unknown, but some experts think it may be linked to certain genes, environmental factors, or bacterial or viral infection.

For patients who experience atypical desquamation, allergy and blood tests may be given in an attempt to identify a cause. Skin biopsy may also be used to diagnose or rule out certain conditions that cause skin peeling. Treatment generally depends on the specific cause. Symptoms may be controlled in part, however, with the use of moisturizing creams and aloe vera gel or lotion.