What is it?
Most are harmless, except for the brown recluse spider (has a violin-shaped mark on upper back) and the black widow (has a red hourglass mark on its abdomen).
What to look for
Pain, burning, itching, and redness. A brown recluse's bite develops into a bull's-eye blister that turns black. A black widow's bite may leave faint red fang marks and swell.
What to do
Wash the area with soap and water, apply an ice pack, and see the doctor right away if you suspect your child's been bitten by either of these spiders (both are usually found in warm climates).
How to prevent it
Don't let your child play in spider hideouts like cellars, closets, attics, garages, and on or near woodpiles.