Chronic, noncontagious skin disorder characterized by superficial skin inflammation and intense itching

Marked by exacerbations and remissions

May appear at any age but typically begins during infancy or early childhood (may then subside spontaneously, followed by exacerbations in late childhood, adolescence, or early adulthood)

In approximately 75% of affected children, development of hay fever or asthma

Allergic mechanism of hypersensitivity results in a release of inflammatory mediators through sensitized antibodies of the immunoglobulin (Ig) E class.

Histamine and other cytokines induce acute inflammation.

Abnormally dry skin and a decreased threshold for itching set up the “itch-scratch-itch” cycle, eventually causing lesions (excoriations, lichenification).

Exact cause unknown (combination of genetic and environmental factors likely)

Possible contributing factors:

Atopy, such as asthma, hay fever, or urticaria (or similar family history) (see Factors contributing to atopy, page 30)