August 22, 2011

Dermatitis, also referred to as eczema, is an inflammation of the skin. This is a common condition that has a variety of different causes and presentations. It may be acute or chronic and extent of involvement may be localized or generalized. Depending on the specific features, various types of dermatitis have been classified. Itching is a common feature.

Atopic dermatitis is most common in infants and children and is often seen in individuals with family members who have asthma or hayfever. It begins in infancy and many children outgrow it by adolescence. It is characterized by red and itchy patches with a predilection for skin folds such as behind the elbows or knees as well as the neck, wrists, and ankles. The areas also have a tendency to become infected due to introduction of bacteria from scratching. Over time, the skin in these areas becomes thickened with a leathery appearance. It is most commonly treated with topical corticosteroids or newer nonsteroid prescription medications called topical immunomodulators. Oral antihistamines are often required to reduce the itching that can be so severe as to interfere with sleep and daily activities. Antibiotics may be required for secondary infection. Moisturization with bland emollients and avoidance of overly drying the skin such as bathing too frequently are also helpful.

Contact dermatitis arises as a result of an allergic or irritant reaction due to substances touching the skin. Examples include poison ivy, costume jewelry, or perfumes in soaps or laundry detergent. Signs and symptoms include redness and itching, and depending on the severity there can be significant swelling and formation of blisters. These skin changes are limited to the site of exposure to the substance that elicits the allergic or irritant reaction. Treatment consists primarily of identifying the cause and avoiding it; however, resolution can be hastened with topical corticosteroids and, in severe cases, oral corticosteroids. If the condition is chronic and the inciting substance is unclear, skin patch testing may be performed to identify the causative allergen.

Seborrheic dermatitis is characterized by greasy yellowish scaling on the scalp and, in severe cases, the face. It is more common in adults, but can be seen in infants in the form of cradle cap. The presence of yeast is thought to play a role in its development. It may occur during times of stress or in people who have neurologic conditions. It is treated with medicated dandruff shampoos, topical corticosteroids, and antiyeast preparations.

Stasis dermatitis usually occurs on the lower legs and is characterized by itchy red and scaly patches. Over time, it leaves behind brown patches that are generally asymptomatic. The cause is attributed to fluid accumulation in the tissues beneath the skin, and is often seen in association with varicose veins or ankle swelling. Improving the condition that is causing fluid buildup in the legs is the most beneficial treatment, and topical corticosteroids are often used if the situation is chronic. Because stasis dermatitis is usually asymptomatic, it often goes untreated and can result in eventual ulceration of the skin, which can be difficult to heal.

SEE ALSO: Adolescence, Asthma

Suggested Reading

Bergstresser, P. R. (1989). Contact allergic dermatitis. Archives of Dermatology, 125, 276—286. Rietschel, F. L., & Fowler, J. F. (1995). Fisher’s contact dermatitis (4th ed.). Philadelphia: Williams & Wilkins.

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