Atopic Dermatitis

Atopic dermatitis is a chronic (long-lasting) disease that affects the skin. The word "dermatitis" means inflammation of the skin. "Atopic" refers to diseases that are hereditary, tend to run in families, and often occur together. In atopic dermatitis, the skin becomes extremely itchy and inflamed, causing redness, swelling, cracking, weeping, crusting, and scaling.

Atopic dermatitis most often affects infants and young children, but it can continue into adulthood or first show up later in life. In most cases, there are periods of time when the disease is worse, called "exacerbations" or "flares", which are followed by periods when the skin improves or clears up entirely, called "remissions". Many children with atopic dermatitis enter into a permanent remission of the disease when they get older, although their skin often remains dry and easily irritated. Environmental factors can activate symptoms of atopic dermatitis at any time in the lives of individuals who have inherited the atopic disease trait.

How common is atopic dermatitis?

Atopic dermatitis is very common. It affects males and females equally. Atopic dermatitis occurs most often in infants and children and its onset decreases substantially with age. Scientists estimate that 65 percent of patients develop symptoms in the first year of life, and 90 percent develop symptoms before the age of 5. Onset after age 30 is less common and often occurs after exposure of the skin to harsh conditions. People who live in urban areas and in climates with low humidity seem to be at an increased risk for developing atopic dermatitis.

About 10% of all infants and young children experience symptoms of the disease. Roughly 60 percent of these infants continue to have one or more symptoms of atopic dermatitis even after they reach adulthood.

What is the difference between atopic dermatitis and eczema?

Eczema is a general term for many types of skin inflammation (dermatitis). Atopic dermatitis is the most common of the many types of eczema. Several other forms have very similar symptoms. The diverse types of eczema are listed and briefly described below.

Types of Eczema

• Atopic dermatitis: a chronic skin disease characterized by itchy, inflamed skin
• Contact eczema: a localized reaction that includes redness, itching, and burning where the skin has come into contact with an allergen (an allergy-causing substance) or with an irritant such as an acid, a cleaning agent, or other chemical
• Allergic contact eczema: a red, itchy, weepy reaction where the skin has come into contact with a substance that the immune system recognizes as foreign, such as poison ivy or certain preservatives in creams and lotions
• Seborrheic eczema: a form of skin inflammation of unknown cause that presents as yellowish, oily, scaly patches of skin on the scalp, face, and occasionally other parts of the body
• Nummular eczema: coin-shaped patches of irritated skin (most commonly on the arms, back, buttocks, and lower legs) that may be crusted, scaling, and extremely itchy
• Neurodermatitis: scaly patches of skin on the head, lower legs, wrists, or forearms caused by a localized itch (such as an insect bite) that becomes intensely irritated when scratched
• Stasis dermatitis: a skin irritation on the lower legs, generally related to circulatory problems
• Dyshidrotic eczema: irritation of the skin on the palms of hands and soles of the feet characterized by clear, deep blisters that itch and burn