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Symptoms
By Mayo Clinic staff
Signs and symptoms of a poison ivy rash include:
- Redness
- Itching
- Swelling
- Blisters
Often, the rash looks like a straight line because of the way the plant brushes against the skin. But if you come into contact with a piece of clothing or pet fur that has urushiol on it, the rash may be more spread out. The reaction usually develops 12 to 48 hours after exposure and typically lasts two or three weeks.
The severity of the rash depends on the amount of urushiol that gets on your skin. A section of skin with more urushiol on it may develop a rash sooner. You can also transfer the oil to other parts of your body with your fingers.
Your skin must come in direct contact with the plant's oil to be affected. Blister fluid doesn't spread the rash.
When to see a doctorSee your doctor if:
- The reaction is severe or widespread
- The rash affects your face or genitals
- Blisters are oozing pus
- You develop a fever greater than 100 F (37.8 C)
- The rash doesn't get better within a few weeks
- Auerbach PS. Wilderness Medicine. 6th ed. Philadelphia, Pa. Elsevier Mosby: 2011. http://www.mdconsult.com/books/page.do?eid=4-u1.0-B978-1-4377-1678-8..00063-5--s0055&isbn=978-1-4377-1678-8&uniqId=343851441-3#4-u1.0-B978-1-4377-1678-8..00063-5--s0055. Accessed July 3, 2012.
- Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 5th ed. Edinburgh, U.K.; New York, N.Y.: Mosby Elsevier; 2010. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-0-7234-3541-9..X0001-6--TOP&isbn=978-0-7234-3541-9&uniqId=230100505-57. Accessed July 3, 2012.
- Prok L, et al. Poison ivy (Toxicodendron) dermatitis. http://www.uptodate.com/index. Accessed July 3, 2012.
- Poisonous plants. National Institute for Occupational Safety and Health. Centers for Disease Control and Prevention. http://www.cdc.gov/niosh/topics/plants. Accessed July 3, 2012.
- Outsmarting poison ivy and other poisonous plants. U.S. Food and Drug Administration. http://www.fda.gov/forconsumers/consumerupdates/ucm049342.htm. Accessed July 3, 2012.
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