You’ve heard of it. You’ve maybe even suffered from it. Those curved lines of red, itchy bumps or blisters after a hike or a play day in the woods are the tell-tell signs you’ve stumbled into poison ivy, poison oak or poison sumac. Even if you are vigilant about avoiding the (mostly) three-leaved plants on your outdoor adventures, you can still become a victim. Here are five things you should know about these common rash-causing plants.
Poison ivy is a member of the Rhus or Toxicodendron genus of plants, which also includes poison oak and poison sumac. Poison ivy, poison oak and poison sumac are common all over the United States. If you’re an avid hiker or otherwise enjoy being outdoors, it’s a good idea to become familiar with pictures of the various Rhus plants. And you may know the basics about poison ivy, oak and sumac — but you can never know too much!
5 things you may not know about poison ivy, oak and sumac
1. Fido is a carrier
While animals appear to be immune to urushiol, the resin from the Rhus plants that causes the allergic reaction, your pets can run through a patch of poison ivy, oak or sumac and transfer it to you.
When you give your pup a petting, you’ve made contact with urushiol just as if you’d touched the poison plants yourself. To avoid getting exposed, wear gloves and bathe your animal. If it isn’t feasible to give your pet a bath after every jaunt outside (this is especially true of cats), a baby wipe or a disposable washcloth might do the trick. Or simply deter your animals from romping around areas that have poison oak, ivy or sumac.
2. Heat can worsen the effects of a poison ivy rash
Heat tends to make the rash even more inflamed, according to Dr. Greene, online pediatric expert for WebMD and a variety of magazines. Dr. Greene suggests not only staying out of hot weather but advises patients with a poison ivy rash to take cool or lukewarm baths. If you happen to be camping, consider getting in the cold lake or stream to keep your body cool.
3. Burning poison ivy, poison oak or poison sumac can result in severe allergic reaction
By touch, the Rhus plants do not pose any serious health risks. However, because the plants’ urushiol toxin is not hampered by fire, burning it can actually cause serious illness. Inhaling or being exposed to smoke from burning poison ivy, oak or sumac can result in a serious allergic reaction in the nasal passages, lungs and throat as well as on the skin. If you are exposed to smoke from burning poison ivy, oak or sumac, get to a health care provider immediately.
4. Though the plants die down in winter, they are not dormant
Urushiol remains active for at least five years on surfaces, and especially in dead Rhus plants. Since urushiol is found in the leaves, stems and roots of poison ivy, oak and sumac plants, you can get a rash even in the winter, when a plant has lost all of its leaves. Therefore, learn to identify the poisonous plants in all seasons. In addition, poison ivy vines are sometimes found on firewood, which you should reconsider using since the burning of the urushiol can cause a toxic (and painful) reaction.
5. Contact dermatitis from poison ivy, oak or sumac is not contagious
Contrary to popular belief and media misconception (How many TV shows have you seen where one character gets a poison ivy rash from touching someone else?), you can’t “catch” contact dermatitis from touching other people unless they still have the urushiol on their bodies or clothing. In addition, the rash will only appear where urushiol makes contact on the skin. It does not spread. It may seem to spread, however, as the rash can appear over a period of time rather than all at once.