Bo Wood, age 11, of Franklin, N.C., for his question:

WHY DOES POISON OAK ITCH?

Some experts say that poison oak and poison ivy are the same, with oak growing in bush form and ivy growing on vines. Others say there are a few differences: the poison oak leaflets are more deeply notched. Poison oak is found in the woods and thickets of many parts of the United States and Canada.

A poisonous oil is produced from the plant. When contact is made with the   body, a rash and watery blisters can result. The poison also makes the skin itch. A crust often develops on the skin and the painful itching irritation can last for many days. Extreme caution must be taken when walking or working in areas where poison oak is common.