Patch shapes vary depending on location. The rash appears mostly on the thighs, groin, trunk and armpits, and on the faces of children. As the patch enlarges, the center may clear, giving a ring- like appearance. It may be warm, but isn't usually painful. However, researchers said, some people never develop a rash.
People can pick up ticks during walks in parks or the woods, or while hiking and camping.
Children are especially susceptible because they run around in tall grass, play in wooded areas and roll on the ground, researchers noted. The individual risk of getting Lyme disease is reasonably small. Only about 12 percent to 15 percent of ticks actually carry the bug. Experts said removing ticks from the body quickly may prevent a person from contracting Lyme disease. Ticks generally must feed on a person for 24 to 48 hours before the person becomes infected.