Poison ivy rash is a type of allergic contact dermatitis caused by an oily resin called urushiol. It's found in the leaves, stems and roots of poison ivy, poison oak and poison sumac. This resin is very sticky, so it easily attaches to your skin, clothing, tools, equipment and pet's fur. You can get a poison ivy reaction from:
- Direct touch. If you touch the leaves, stem, roots or berries of the plant, you may have a reaction.
- Touching contaminated objects. If you walk through some poison ivy and then later touch your shoes, you may get some urushiol on your hands, which you may then transfer to your face or body by touching or rubbing. If the contaminated object isn't cleaned, the urushiol on it can still cause a skin reaction years later.
- Inhaling smoke from the burning plants. Even the smoke from burning poison ivy, poison oak and poison sumac contains urushiol and can irritate or harm your nasal passages or lungs.
A poison ivy rash itself isn't contagious — blister fluid doesn't contain urushiol and won't spread the rash. And you can't get poison ivy from another person unless you've touched urushiol that's still on that person or his or her clothing.
Aug. 11, 2015
- AskMayoExpert. Contact dermatitis. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
- Bolognia JL, et al., eds. Irritant and allergic contact dermatitis, occupational dermatoses and dermatoses due to plants. In: Dermatology Essentials. Philadelphia, Pa.: Elsevier; 2014. http://www.clinicalkey.com. Accessed June 15, 2015.
- Wolff K, et al. Contact dermatitis. In: Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology. 7th ed. New York, N.Y.: The McGraw-Hill Companies; 2013. http://www.accessmedicine.com. Accessed June 15, 2015.
- Prok L, et al. Poison ivy (Toxicodendron) dermatitis. http://www.uptodate.com/home. Accessed June 16, 2015.
- Poisonous plants. National Institute for Occupational Safety and Health. Centers for Disease Control and Prevention. http://www.cdc.gov/niosh/topics/plants. Accessed June 15, 2015.
- Outsmarting poison ivy and other poisonous plants. U.S. Food and Drug Administration. http://www.fda.gov/forconsumers/consumerupdates/ucm049342.htm. Accessed June 15, 2015.
- AskMayoExpert. Poison ivy rash (adult and pediatric). Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2014.
- Patient education: Poison ivy. American Academy of Family Physicians. http://www.clinicalkey.com. Accessed June 15, 2015.
- Poison ivy. Nursing. 2014;6:47.
- Gibson LE (expert opinion). Mayo Clinic, Rochester, Minn. July 10, 2015.