Eczema is an inflammation of the skin that can have a variety of causes. There are acute and chronic forms of eczema.
Symptoms can vary, but generally, all types of eczema have some symptoms in common: skin itching, redness, and tiny bumps or blisters. If these symptoms remain untreated, the skin can become thick, scaly, and dry, with associated areas of hair loss and color changes.
Atopic and contact dermatitis are two common types of eczema.
Atopic eczema is a chronic condition often associated with a personal or family history of asthma, allergic rhinitis, and/or atopic eczema. Itching is the most noticeable symptom. It often leads to scratching and rubbing, which can lead to thickened skin. Eczema typically appears before age 5, and is usually located on the face and outside surfaces of the arms and/or legs. It can appear as reddened skin, blisters, and oozing areas. Many cases last only until the child becomes a teenager. The condition may recur in adolescence and adulthood, however, as chronic dermatitis. The symptoms include scaling, dryness, and thickened skin over the face, neck, upper chest, and inside of the elbow and behind the knee.
Contact dermatitis can be either irritant or allergic. Irritant, the more common type, is caused by contact with substances such as acids, solvents and detergents that irritate or have a toxic effect on the skin. No allergic reaction is involved. The skin reaction may occur only hours after exposure, or it may take multiple exposures before eczema develops. A common cause of irritant contact dermatitis is frequent hand washing.
Allergic contact dermatitis is a delayed response to allergens commonly found in the environment. The immune system becomes sensitive to the allergen 10 to 14 days after exposure. There is no reaction until the allergen is encountered a second time. The eczema develops one to seven days after this second or subsequent exposure. Some common allergens include certain plants (poison ivy, oak, and sumac), metals (nickel), cosmetics, medications applied to the skin, and latex.
Other types of eczema
A third type of eczema is called nummular eczematous dermatitis. This condition is defined by recurrent, coin-shaped patches predominantly on the outer surfaces of the arms and legs, and less often on the trunk. Patches of blisters and small bumps spread to become scaly and thickened. Mild to severe itching accompanies the patches. Although the cause is unknown, many factors acting alone or in combination may contribute to this condition. Dry skin is a frequent contributor, and the disease reaches its peak in winter months. Irritating substances such as wool and soap, and frequent bathing may contribute.
Hand eczema is another type of eczema that usually appears during the winter as areas of dry, cracked skin. The most common causes are constant exposure to soap and water from frequent hand washing, nummular dermatitis, and allergic contact dermatitis. Hand eczema is most common among homemakers, cooks, food handlers, and medical personnel. The best treatment is to avoid the substance that's irritating your skin, whether it's soap, solvents, detergents, or frequent exposure to water. To limit your exposure to water, you can wear cotton-lined rubber gloves, or wear cotton gloves under plastic gloves while doing chores.
Seborrheic dermatitis, yet another type of eczema, occurs in hairy or oily areas of the skin, including the face, ears, and chest. It appears as red patches and yellow, greasy scales. Dandruff is a type of seborrheic dermatitis of the scalp. Infants may develop seborrheic dermatitis (called cradle cap), but it usually disappears around age 6 months. It may reappear after adolescence. Common treatments used include special shampoos that contain ketoconazole, sulfur, salicylic acid, selenium sulfide, or pyrithione zinc.
Your health care provider will ask about your personal and family allergy history and any recent exposure to irritating chemicals. He or she will examine your skin. It is important to tell your provider what the area that might be eczema looked like when you first noticed the problem, how it has changed, and what you have done to treat it.
You can help prevent atopic eczema flare-ups and contact dermatitis by limiting or avoiding your exposure to irritating substances. Avoid frequent hand washing and frequent or lengthy bathing. Use tepid water instead of hot water for bathing. Use washcloths that aren't abrasive. Wear clothing that is 100 percent cotton; avoid rough clothing and clothing made of wool. When laundering, don't use fabric softeners. If you use perfumes or makeup, make sure it doesn't burn or itch. Avoid cigarette smoke and aerosols, which can irritate skin.
To prevent eczema, shower or bathe with a gentle soap (used sparingly), then pat dry so you leave a little moisture on your skin. Apply a moisturizing lotion while skin is still damp. Use a humidifier to add moisture to indoor air during the winter. Don't overdress during the day or use so many blankets on the bed at night that you become sweaty.
To prevent contact dermatitis, avoid irritating chemicals, plants, and nickel jewelry.
The goals of eczema treatment are to control inflammation and itching, and prevent the problem from getting worse. Mild over-the-counter (OTC) corticosteroid creams are available that can help alleviate symptoms and signs such as itchiness, redness, and roughness. Use these only for a limited amount of time and only intermittently. Your health care provider may prescribe a more potent prescription corticosteroid ointment or cream, and/or an antihistamine. Atopic dermatitis and contact dermatitis may respond well to either mild or, when indicated, more potent topical steroids.
Other topical medications that treat eczema, called topical immunomodulators (TINs), also are available. Pimecrolimus and tacrolimus are examples.