What is this Condition?
Dermatitis is an inflammation of the skin that occurs in several forms, including atopic, seborrheic, nummular (coin-shaped), contact, chronic, localized neurodermatitis, exfoliative, and stasis. The discussion below focuses on atopic dermatitis. (For information on contact dermatitis, see Uncovering the cause of contact dermatitis.)
Atopic dermatitis (also called infantile eczema) is a chronic skin inflammation that affects about 9 out of every 1,000 people. It’s often associated with allergy-related diseases, such as bronchial asthma and allergic rhinitis. It usually develops in infants and toddlers ages 1 month to 1 year – typically in those with a strong family history of allergy-related disease.
Atopic dermatitis typically flares up and subsides repeatedly before finally resolving during adolescence. However, it can persist into adulthood. It can lead to viral, fungal, or bacterial infections and can even cause eye disorders.
What Causes it?
The cause of atopic dermatitis is unknown, but there’s a genetic predisposition, which is worsened by food allergies, infections, irritating chemicals, extremes in temperature and humidity, and emotions. Approximately 10% of childhood cases are caused by allergies to certain foods – especially eggs, peanuts, milk, and wheat. Atopic dermatitis tends to flare up with increased sweating, psychological stress, and extremes in temperature and humidity.
Irritation is an important secondary cause of atopic dermatitis. It seems to change the skin surface structure, which eventually leads to chronic skin irritation.
What are its Symptoms?
The skin lesions of atopic dermatitis start as reddened areas on very dry skin. They typically appear on the forehead, cheeks, knees, elbows, legs, and neck. During flare-ups, itching and scratching cause swelling, crusting, and scaling. Eventually, chronic lesions lead to numerous areas of dry, scaly skin with white, firm, raised, intensely swollen lesions, which become thick and hard.
Intense itching may cause swelling and unusual darkening of the upper eyelids, with a double fold appearing under the lower lids. In rare cases, atopic cataracts (clouding of the eye lens) may develop between ages 20 and 40.
How is it Diagnosed?
To diagnose atopic dermatitis, the doctor examines the person’s skin and checks for a family history of allergies and chronic inflammation. To rule out other inflammatory skin conditions, such as diaper rash, seborrheic dermatitis, and chronic contact dermatitis, the doctor checks for typical distribution of skin lesions.
How is it Treated?
The person with atopic dermatitis must eliminate known allergens and avoid irritants, extreme temperature changes, and other triggers.
To relieve itching and inflammation, the doctor may prescribe a topical steroid ointment such as Cortaid, which can be especially effective when applied after bathing. Between steroid doses, the person should use a moisturizing cream to help the skin retain moisture. Oral steroids should be reserved for extreme flare-ups.
Weak tar preparations and ultraviolet B light therapy may be used to thicken the skin’s outer layer. If the doctor determines that a bacterial agent is involved, he or she may prescribe an antibiotic.