HomeHealth Topics A to ZA Guide to Poison Ivy
Health Topics

A Guide to Poison Ivy

By Alix Charles, MD, FAAD

The rash from poison ivy is due to a skin allergy to an oily substance called urushiol found throughout the whole plant. If you are allergic to poison ivy, you will get an itchy, red rash with little blisters (a type of eczema). After you touch the plant, the rash may not come for a day or two later. Summer time is the most common time to get poison ivy because you are out playing and working in the yard.

Did you know?

  • Not everyone is allergic to poison ivy. If you are allergic, it’s the second time you touch the plant (and every time after) that you will get the rash.
  • You can get the allergic rash from poison ivy in the winter if you touch the stalks or roots
  • You can get a similar allergic rash to many other plants
  • Poison ivy has two “brothers” that live in other parts of the country- poison oak (on the west coast and in the south) and poison sumac (on the east coast). 
  • The poison ivy oil, urushiol, is found in other things too such as the skin of a mango and in the shell of a cashew nut
  • The poison ivy oil can fly through the air if the plant is thrown into the fire

How to avoid poison ivy:

Avoid the plant. Learn what poison ivy looks like: 

  • The leaves are arranged in groups of three on a stalk – “Leaves of three, let them be!” 
  • It’s a plant that forms vines
  • It can grow on the ground or up trees and fence posts
  • It can be green in the summer and red, yellow or orange in the fall
  • It can have little berries in the summer

Your pets can bring in the poison ivy oil on their fur so make sure they are not in contact with the plants either.

What to do if you get poison ivy:

  • Wash the skin immediately after you come into contact with the plant with soap and water. You only have about 10 minutes to remove the oil off the skin before it gives you a rash the next day! 
  • Cool compresses and over the counter hydrocortisone cream can be helpful
  • Try not to scratch!
  • The rash can last up to 3 weeks

See your dermatologist for prescription medications if the rash is very uncomfortable or worrisome looking.

Topics and Subtopics: Skin Health

Physicians & Experts

Learn more about:
Receive more health tips and DMG news right in your inbox!
Sign up for the Live Life Well newsletter