Spreading poison ivy?

Poison ivy can itch like crazy, and make you want to scratch just as much. You should resist the urge to scratch those poison ivy blisters, but not because the fluid will spread the poison ivy. The risk from scratching is the possibility of infection, says the American Academy of Dermatology.

The rash from poison ivy is caused by urushiol (you-ROO-shee-ol), the oil found in the sap of poison ivy (and its cousins, poison oak and poison sumac). The oil is very persistent -- you can get it on your skin from touching the plants, or from the fur of pets that have touched the plants, even from clothes or tools. The oil penetrates your skin and the rash usually appears within 12 to 48 hours. The rash may take longer to appear in areas where the skin is thicker and tougher, which may make it appear that the infection is spreading.

If you know you've been in contact with poison ivy, wash any exposed areas of skin in cold water as soon as possible. Washing with soap and water up to 30 minutes after exposure will help. Wash your clothes too, and avoid getting the oil on rugs or furniture in your house -- urushiol can stay active for months.

July 27, 2002