Poison Ivy, Oak, and Sumac

Diagnosis

The distinct rash poison ivy, poison oak, and poison sumac produce are sufficient to make the diagnosis.

Prevention and Screening

Avoiding poisonous plants is your best defense. Learn to recognize the appearance of poison ivy, oak, and sumac. Poisonous plants can grow as vines or shrubs. Poison ivy and poison oak have three leaflets per leaf, whereas poison sumac can have as many as 13 leaflets per leaf. The leaves of poisonous plants may be dull or shiny, and are anywhere from one to five inches in length. The edges of the leaves may be pointy, lobed, or smooth. Though usually green, in autumn leaves can turn yellow or red; in spring they bear small green or yellow flowers.

Wear and wash protective clothing. If you spend a lot of time outside (particularly in wooded areas), wear clothing that covers your arms and legs. Be sure to wash your clothes after spending time outdoors in the vicinity of poisonous plants, because the sap can get on them and stay on them for months.

Lotion or deodorant can be used to block a reaction. A lotion available in most drug stores called bentoquatam (Ivy Block) can act as a barrier to poisonous plants. When applied 15 minutes before exposure, it keeps urushiol from being absorbed through your skin. . You can also try what members of the US Forestry Service do before they head into the woods: spray some deodorant on your arms and legs. Aluminum chlorohydrate (the active ingredient in deodorant) can keep urushiol from irritating your skin.

Wash anything that may have touched a poisonous plant. People often get rashes after their pets bring urushiol into the house. Likewise, handling a Frisbee or a football that has landed in a patch of poison ivy, oak, or sumac can cause a rash. Touching towels or clothes that have urushiol on them can as well. Be sure to wash anything that may have come into contact with a poisonous plant. Wash exposed skin areas with soap and water right way. The longer you wait, the less effective washing is. If you’re in the woods, use water from a lake or stream. If you catch it within the first half hour, you may not have a reaction. If you have some rubbing alcohol handy, you can use it to inactivate urushiol.