Published: Mar. 2, 2012
Updated: Mar. 2, 2012
By Emily Mitchell
When a walk in the woods leaves you with red, itchy bumps, poison oak or poison ivy is often the culprit. Or, actually, the oily substance on the leaves -- oleoresin -- is to blame.
Stephanie Foley, MD, a resident at Duke Family Medicine, explains that the bumps and itchiness are a person’s allergic reaction to the oleoresin from the poisonous plants.
“Like other allergies, each person’s immune system is different, so there is no rhyme or reason as to why some people are allergic to the plants while others are not,” Foley says.
So, what should you do if you know, or even think, you’ve come in contact with poison ivy or poison oak?
According to family medicine practitioner Brian Halstater, MD, if you think you may have touched a poisonous plant or had an exposure to the oils, washing the area with soap and water within the first five to 10 minutes can prevent a reaction.
And when it comes to breaking down the oils and getting them off your skins, nothing has been proven to be more effective than good old soap and water.
It’s also a good idea to wash clothes that you suspect have had contact with the poisonous plants. Washing them immediately with soap and water will remove the oleoresin and prevent a future reaction when you wear them again.
Though there is a myth that the oils from the plants can stay harmful for a year, this is highly unlikely, says Foley. “However, the oil can stay intact after transfer, so that’s why you need to wash thoroughly immediately after contact.”
Allergy to poison oak or poison ivy typically presents as a rash that has red bumps filled with clear fluid.
The reaction typically occurs 12 to 24 hours after exposure to the plant, and the length of the reaction is based on these severity of the allergy. Reactions in children, elderly, and pregnant women could be more severe, and may require a more aggressive treatment.
For the itching, Foley suggests using a topical treatment such as Benadryl, calamine lotion, and corticosteroids like 1 percent hydrocortisone cream. For moderate to severe cases, you doctor might prescribe oral Benadryl or corticosteroids.
While it may be hard to do, avoid scratching the reaction and don’t pop the bumps, as this releases poison back onto your skin.
People who know that they are allergic to these plants should try to prevent exposure to the plants.
When working outside, especially around suspected poison ivy or poison oak, take precautions to avoid touching the plants you’re your bare skin, advises Halstater. Possible precautions include wearing gloves, long-sleeved shirts or long pants, close-toed shoes, or even knee-high socks -- anything to prevent the oleoresin from transferring to your skin.
And, of course, knowing what the plants look like is an important factor in avoiding their poisonous leaves. View the slideshow to familiarize yourself with the plants so you will know what to avoid.
Medical care should be sought anytime there is a reaction anywhere on the face, if there is any difficulty or changes in breathing, a large area of skin is affected, if there is any fevers, chills, or signs of infection. If the reaction is persistent, you should also see your provider.
Small children, pregnant women, and the elderly should be evaluated as well.