How To Prevent a Skin Reaction from Poison Ivy

The rash that develops on your skin after coming in contact with poison ivy is caused by your skin’s reaction to a toxic chemical in the plant: an oil called urushiol. Urushiol is released when the leaves, stem or other parts of the poison ivy plant are touched, bruised, or otherwise stimulated. The oil can get on your clothing or on a pet and then be transferred to your skin up to several hours later. If you are one of those allergic to urushiol, a rash will develop on your skin 2-7 days after the contact.

Once the rash has developed, it cannot be spread around any more. The fluid in the blisters on your skin comes from your body and its reaction to the urushiol. The fluid is not urushiol and it will not cause additional rash to develop. Once you have the poison ivy rash, it can no longer be spread around. There are various over-the-counter medicines to deal with the itching and swelling caused by the skin rash. But you can prevent the rash from developing in the first place if you’re paying attention.

If you know you have been in contact with poison ivy within the last hour or so, you can prevent a rash from developing by rinsing the affected area with rubbing alcohol. Urushiol is soluble in alcohol, but not very soluble in water. Washing with soap and water just spreads the poison around. It gets on your hands, between your fingers, and can wind up all over your body. Instead:

1. Rinse the affected area with rubbing alcohol. Do not use a wash cloth. I keep a bottle of 70% rubbing alcohol in the potting shed and another under the kitchen sink. If I find myself with a handful of poison ivy when I’m out weeding in the flower bed, I run and put some rubbing alcohol in a small bowl, and rinse my fingers and hands thoroughly. (I might dilute the alcohol half and half with water.)

2. Then wash with soap and water. The alcohol rinses off the urushiol like soap and water cannot. The sooner after exposure you can rinse with alcohol, the better. After several hours it will be too late.