If you get an itchy rash with red bumps or weeping blisters a few days after doing yardwork, it’s likely due to poison ivy (poison oak doesn’t grow in Indiana and poison sumac only grows in swampy areas). The rash is an allergic response to the oil on the plant, which is called urshiol. Your body takes a few days to develop the allergic response. Poison ivy rash is not contagious, even if you have a weeping rash.

It sometimes looks like it is spreading to different parts of your body, but this is because the delayed body reaction occurs at different speeds, depending on how much of the plant oil you have been exposed to. Rash that appears under clothed areas is likely passed from hands that had the plant oil on them. About 20% of people are not allergic to poison ivy.

Avoid poison ivy by not touching anything with three leaves. Hairy vines on trees and fence lines may also be poison ivy. It often hides in other brush, so beware. Sometimes pets will have the oil on their fur after running through the woods; this could be passed to you. Burning brush that has poison ivy can be dangerous, if the smoke is inhaled.

Wear gloves and long sleeves, if possible, when working with brush. Wash you hands and change clothes as soon as you are done. The less time that the oil is exposed to your skin, the better you will do.

Untreated, poison ivy lasts about two weeks. Calamine lotion or hydrocortisone cream can be soothing, but they don’t work great. Consider seeing your doctor if the itch is unbearable, if large parts of your body are covered, or if the rash is getting near your eyes.

Standard medical treatment is prednisone, in pill or shot form. It works by reducing the body’s allergic response, and usually shuts down the itch in 24 hours. Prednisone can have the side effect of making you feel like Superman, which can be useful when you are ready to get back to finishing that yard work.