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Is Poison Ivy Contagious? - Poison Ivy Questions and Answers

Poison Ivy Answers

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Updated May 06, 2014

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

Is poison ivy contagious? When can my son go back to school?

These are common questions when a child is diagnosed with poison ivy.

A severe rash from poison ivy may keep a child out of school for a day or two, but it won't be because the rash is contagious. Instead, a severe poison ivy rash, especially one that involves the face, might cause enough swelling, redness, or blisters, that a child might simply not want to be seen in school until it gets better.

Is Poison Ivy Contagious?

Parents often think that poison ivy is contagious because, like many red, itchy rashes, it looks contagious. Unlike other skin rashes, such as scabies or chicken pox, you can't get poison ivy by touching someone else's poison ivy rash though.

So why do so many people think poison ivy is contagious?

In addition to just assuming an itchy rash is contagious, the way that poison ivy spreads is likely what keeps this long-standing poison ivy myth going.

How Poison Ivy Spreads

After being exposed to poison ivy, susceptible kids often develop the classic poison ivy rash on one or more small areas of their skin. Over the next few days to a week, the rash typically then spreads to many other areas of their body.

This pattern makes many people think that there is something on the rash or in the blisters that the child spreads over their body while scratching.

Urushiol

What is actually happening is that the skin that first broke out in a rash likely just had more exposure to urushiol, a chemical found in poison ivy that triggers a rash. Other areas of the body that break out later probably had less contact or were thicker and less susceptible to the urushiol.

The urushiol itself is not present in skin blisters or on the rash and can't be spread from one person to another or around one person's body.

Urushiol can sometimes remain on clothing, which can continue to trigger a poison ivy rash every time a child touches or wears the clothing. Or a child can continue to be exposed to poison ivy outside if he doesn't recognize the poison ivy plants.

Having some urushiol on his fingernails from the initial exposure might also be a way that a child could spread the rash around more, as he touches other areas of his body that weren't exposed the first time.

Urushiol can bind and penetrate the skin very quickly, which is why poison ivy experts say that you only have between 5 and 20 minutes to have any chance of washing it off and avoiding, or at least reducing, the poison ivy rash. In addition to not being contagious, that is why you can't spread poison ivy around much after you have been exposed.

Avoiding Poison Ivy

Even though poison ivy isn't contagious and usually doesn't mean any missed school days, the rash is terribly itchy and uncomfortable.

So do everything you can to help you kids avoid poison ivy in the first place.



Sources:

Froberg BPlant poisoning. Emerg Med Clin North Am. 01-MAY-2007; 25(2): 375-433

Habif: Clinical Dermatology, 5th ed.

Mark BJ. Allergic contact dermatitis. Med Clin North Am. 01-JAN-2006; 90(1): 169-85

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