Wayne Jones, age 10, of Claremore, Okla., for his question:

WHAT IS AN ITCH?

There's a saying that goes: if it itches, scratch it. Sometimes that's good advice, and other times it isn't. You shouldn't always scratch an itch.

An itch is a sensation caused by irritation of particular nerves in the skin. Nerve fibers have special endings that are tiny organs able to receive messages. Some nerve endings receive pressure sensations, some receive temperature and some receive pain.

Stimulation of pain nerves in the skin sometimes results in itching.

You shouldn't scratch the type of itch that is caused by poison ivy. Nor should you scratch the itch caused by hives. Instead, relieve the itch with a cool, moist lotion.

Sometimes an itch can be caused by an allergy or a skin infection such as athlete's foot.