By Casey Watkins, MD
Summer is here and now is a good time to remind everyone that if a plant has leaves of three, let it be! Poison ivy is a very common type of allergic contact dermatitis. Contact dermatitis is caused by your body’s reaction to a substance that comes in direct contact with your skin. Poison ivy rashes are most common in the summertime due to more outdoor activities, but it can arise anytime during the year. The allergen that causes the poison ivy rash is caused by the oil in the poison ivy plant called urushiol (you-
ROO-shee-all). This oil is found in the leaves, stems and roots of the plant. Not everyone is allergic to poison ivy, or its close cousins poison oak and poison sumac. However, for 80-90% of adults, only 50mcg of the urushiol oil (about the size of a grain of salt) can cause a rash.
There are a few common misconceptions about poison ivy:
It’s contagious. Actually, the rash cannot be spread from person to person, even if you come into contact with an open blister. The rash is only spread by direct contact with the urushiol.
It spreads. Just as the rash can’t be spread from person to person by contact with the open blisters, it also can’t be spread from one area of the body to another via contact with the fluid in the blisters. However, you can develop a rash through indirect contact with the oil. If the oil gets onto your clothing, a gardening tool, a pet that has the oil on their fur and rubs it against bare skin, or even being exposed to airborne particles of urushiol.
“I’ve never had a reaction, so I must not be allergic.” Often, people won’t break out with the first exposure but become sensitive to the oils the next time they come into contact.
“It’s ok to burn poison ivy.” NEVER burn poison ivy, oak or sumac. The oils can be released into the air, which can then be inhaled. Inhaling the oils can lead to hospitalization as the rash could spread into the lungs.
What to do if exposed to Poison Ivy
If you do get into poison ivy, immediately rinse the affected areas with rubbing alcohol, dish detergent or a poison plant wash. Be sure to wash the area several times, and rinse often, in order to remove as much of the urushiol as possible. If you do develop a rash with itching, wet compresses, hydrocortisone cream and calamine lotion can help reduce the itching and blistering. Oatmeal baths and antihistamines can also help relieve the itching.
While most poison ivy rashes can be cared for at home, if you develop a rash on the face, or if you have a severe reaction (or have had a severe reaction in the past) see your dermatologist as soon as possible. Also, if you develop more severe allergy symptoms, like swelling or difficulty breathing, it is important to be seen by a health care professional immediately.
Poison ivy, oak, and sumac. (n.d.). Retrieved June 09, 2017, from https://www.aad.org/public/diseases/itchy-skin/poison-ivy-oak-and-sumac
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