Poison ivy, poison oak, and poison sumac grow in wooded or marshy areas throughout North America. They actually aren’t really poisonous—they produce a sticky oil called urushiol that causes an itchy, blistering rash after it touches your skin.
You may have heard the saying “leaves of three, let it be”—poison ivy has three shiny leaves, one in the middle and two on either side. Poison oak looks similar, but the leaves are grouped in threes, fives, or sevens, and are larger, more rounded, and have a hairy surface. Poison sumac grows as a shrub or tree, and its leaves grow in clusters of seven to thirteen leaves, with one by itself at the end.
You can avoid coming into accidental contact with posion ivy, oak, or sumac by wearing long-sleeved shirt, long pants, gloves, and closed shoes. If you’ve gotten any of the plants’ oil on your skin, wash it right away with warm soapy water or use alcohol wipes to remove it.
You may see a red rash appear in 24-72 hours and last up to three weeks. Over-the-counter medicine can provide relief from itchiness, as can cool compresses and oatmeal baths. Luckily, the rash isn’t contageous! Seek medical attention if the rash is close to your eyes or is widespread over your body, and go to the emergency room if you experience nausea, fever, shortness of breath, extreme soreness at the rash site, or swollen lymph nodes.
