Poison ivy, poison oak, and poison sumac are common plants. They can cause a rash in some people.
Poison Ivy Rash
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The rash is an allergic reaction to the oils of the plant. This oil is released if the plant is damaged or bruised. The reaction may develop after frequent contact with the plants.
The oil may pass right onto the skin. It may also pass onto items such as clothes, tools, or toys. The rash can occur after contact with these items. The oil on these items can cause a reaction years after first contact.
People may only develop a reaction after repeated contact with the plant. Contact with the oil is likely after:
- Working or playing in wooded areas during the spring, summer, and fall
- Touching pets or animals that have come in contact with these plants
- Handling clothes or objects that have come in contact with these plants
- Being around the smoke of these plants if they are burned
The oils cause a very itchy and red rash. It appears within 24 to 72 hours of contact with the oil. The rash may look streaked and have oozing blisters.
Some people may have a severe reaction. Medical care should be sought for the following symptoms:
- Swelling of the face or throat
- Rash on the genitals
- Swelling or rash that covers more than one–third of your body
- Rapidly spreading rash
The doctor will look at the rash. It may be diagnosed based on appearance and possible contact.
The skin rash can cause discomfort. It will often pass on its own in 2 to 3 weeks.
Scratching can cause further damage to the skin. It can also increase the risk of infection. Treatment can help to ease itching. Steps may include:
- Home care such as cool compresses with water or whole milk
- Antihistamine pills
- Calamine lotion
- Zinc oxide or baking soda to dry oozing blisters
- Diluted aluminum acetate solution (Burow's solution)
Steroid creams to ease inflammation
- Steroid pills for severe rashes
If you have been exposed to poison ivy, oak, or sumac:
- Wash your entire body right away. Use soap and water. Do not scrub hard.
- Wash all clothes or other items that have come in contact with plants.
- Bathe pets in soapy water if they have come in contact with plants.
To avoid contact with poison ivy, oak, or sumac oils:
- Learn what the plants look like and avoid all contact with them.
- Never burn these plants.
- Wear clothes that cover as much skin as possible when in wooded areas. Use gloves when working with plants.
- Bentoquatam is a cream that can be put on the skin. It may help when used before contact with the plants. It can be found in drug stores.
Contact dermatitis. EBSCO DynaMed website. Available at:https://www.dynamed.com/condition/contact-dermatitis. Updated November 29, 2018. Accessed October 30, 2019.
Outsmarting poison ivy and its cousins. US Food & Drug Administration website. Available at: https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm049342.htm. Updated June 6, 2017. Accessed October 30, 2019.
Poison ivy, oak, and sumac: Who gets a rash, and is it contagious? American Academy of dermatology website. Available at: https://www.aad.org/itchy-skin/poison-ivy-oak-sumac-who-gets-contagious. Accessed October 30, 2019.
Last reviewed October 2019 by
EBSCO Medical Review Board
Monica Zangwill, MD, MPH
Last Updated: 9/8/2020