Poison ivy info

Myth: Poison ivy rash is contagious.

Fact: Although the poison ivy rash appears contagious, you cannot catch a rash from someone else, and you cannot spread a rash to other parts of your own body.

Poison ivy is a member of the toxicodendron family of plants, which also includes poison oak and poison sumac. It typically grows as a vine or shrub east of the Rocky Mountains along trails, ponds, and lakes. Poison sumac grows in boggy areas in the southern United States, while poison oak grows as a bush or climbing vine in the western United States.

Urushiol–the oil found in poison ivy, oak, and sumac–causes the typical allergic reaction and resulting rash symptoms. Contact with urushiol can either be direct (read: touching the leaves themselves) or indirect (read: the oil gets on your clothes, bike, shoelaces, etc., and then you touch that object). Most rashes develop within eight to 48 hours after touching the oil, but can take as long as 15 days to form.

Although nasty, your poison ivy rash is not contagious. You can’t catch or spread the rash after it appears, even if you touch it or the blister fluid. Sometimes people believe that the rash is spreading because it appears over different parts of the body later on, but the rash only appears where urushiol has come in contact with the skin. So either the rash is still developing from earlier contact, or you have touched something that still has urushiol on it.

If you think you (or your dog!) has come into contact with poison ivy, oak, or sumac, be sure to wash the affected areas immediately, preferably with a product like Tecnu, which is designed to remove the oil. Wash your clothes and footwear as well. If you do end up with a rash, there’s not much you can do, apart from taking a couple of antihistamine pills and using calamine lotion to help relieve symptoms. Your doctor can also prescribe medications like a sequence of steroids–they don’t stop the itching entirely, but do make the experience slightly more comfortable.

With the apex of poison ivy and poison oak season upon us, your best bet is to avoid the plants all together. Download one of the smartphone apps like LeafSnap (which uses facial recognition software to ID a plant based on its leaves) to help you identify poisonous plants in the field. Or view photos online before you head out in order to know what to avoid on the trail.

And when making a camp fire, never–NEVER–burn the stuff. The only thing worse than getting poison ivy on your skin? Getting it in nasal passages.