Devra Eisenfeld, age 9, of Tucson, Ariz., for her question:

WHAT CAUSES AN ITCH?

When there is an irritation at the termination points of sensory nerves, there's an itching of the skin. The medical term is pruritus. It may involve just one spot on your body or may cover a large area.

Itching is associated with a number of diseases and disorders. Eczema and an allergic reaction to some foods, drugs, cosmetics or plants can cause real problems, as can insect bites. Dry skin can also cause itching.

Most people scratch when they itch. Usually this gives temporary relief. If the cause isn't something serious, gently scratching gives a cure. But care should be taken not to scratch an itching spot if it will irritate the skin. Use cool compresses instead.