Atopic dermatitis

Atopic dermatitis (AD), also known as atopic eczema, is a type of inflammation of the skin (dermatitis). It results in itchy, red, swollen, and cracked skin. Clear fluid may come from the affected areas, which often thicken over time. It typically starts in childhood with changing severity over the years. In children under one year of age much of the body may be affected. As they get older the back of the knees and front of the elbows are the most common area for the rash. In adults the hands and feet are most affected. Scratching worsens symptoms and affected people have an increased risk of skin infections. Many people with atopic dermatitis develop hay fever or asthma.

The cause is unknown but believed to involve genetics, immune system dysfunction, environmental exposures, and difficulties with the permeability of the skin. If one identical twin is affected, there is an 85% chance the other also has the condition. Those who live in cities and dry climates are more commonly affected. Exposure to chemicals or frequent hand washing makes symptoms worse. While emotional stress may make the symptoms worse it is not a cause. The disorder is not contagious. The diagnosis is typically based on the signs and symptoms. Other diseases that must be excluded before making a diagnosis include contact dermatitis, psoriasis, and seborrheic dermatitis.