Poison Ivy Q & A

By Trina Peduzzi, M.D., Pediatric Alliance — Allegheny

Ah, summertime…days are long with sun and fun, picnics and barbecues, playing outside in the waning light. Wait, what is this itchy, bumpy rash that popped up on my daughter’s arm this morning after a fun family weekend? She’s crying and scratching like crazy. Uh oh, could it be poison ivy?


How do I know if my child is allergic to poison ivy?

Most people (85%) will have a rash after exposure to poison ivy. The plant contains an oil, urushiol, which is found in all parts of the plant-stem, leaves, flowers, and berries and is what causes a reaction in humans. It is best to assume that your child will probably have a reaction if she is exposed to the oil, although it appears some people have less of a response than others.


What does the poison ivy rash look like?

A typical poison ivy rash has red patches or streaks, bumps and/or blisters and can cover a small area of skin to very large parts of the body. It is very itchy. If the urushiol oil got on your child’s skin and he scratched the area with the oil, this can spread the oil wherever he touches — face, arms, belly, groin, anywhere.


We were playing in the woods on Sunday. Now it’s Tuesday and my child woke up with a rash. Is this what happens with poison ivy?

Humans have what is called a “delayed type” response to the urushiol in poison ivy, so a rash can commonly occur 12-72 hours after exposure — and even up to 2 weeks after exposure. If your child has had prior bouts of poison ivy, you may see that the symptoms start much sooner after contact (and with more of a vengeance!).


What should I do if I suspect my child has been exposed to poison ivy?

Wash his skin with cool soapy water as soon as possible. Some sources state that if you can get the oil off the skin within one hour of exposure you may be able to prevent or lessen the rash. Make sure to get under fingernails well and really scrub the skin with a sponge, loofah, or cloth to try and remove the oil.

Remove any clothing and launder. Take caution with shoes if a child was running or playing in a potential poison ivy area as the oil from the plant can still be on the soles.


Is my child’s rash contagious? How about the weeping fluid that’s coming from the rash?

Nope, your child is not contagious. It can seem like the rash could be contagious, especially if your child has a small rash one day and the next day a much larger area is affected, but this is due to our delayed-type response. But no one can “catch” poison ivy from your child’s rash. The only way you can get the rash is from touching the oil.
The fluid that can come from the blisters is also NOT contagious. It is serum from blood and does NOT contain the urushiol oil that caused the rash.

However, if your child’s clothes, toys, or dearest cuddly pet friend were also exposed to the poison ivy and if any oil remained on the surface, this COULD produce more rash in your child if she touches the item. Wash any potentially exposed items well to prevent any further exposure. Oil has been reported to last up to 5 (!) years on surfaces. And never burn the poison ivy plant- the oil can become aerosolized and cause very dangerous respiratory problems in people.

What can I try at home if my child does have poison ivy rash?

After making sure that you’ve thoroughly showered your child and washed any potential clothing or other items, here are a few common home remedies:

Calamine lotion — a tried and true pink lotion that is also available over-the-counter and can provide some itch relief.

1 % hydrocortisone ointment –– also available over-the-counter, this mild topical steroid helps reduce inflammation. It is often applied to small areas of the body 2- 3 times a day for a short time. (Prolonged use or using on large areas of the body can be dangerous.)

Cool oatmeal baths — short baths with lukewarm water and colloidal oatmeal (commonly found as Aveeno) may be soothing to the skin and lessen the urge to scratch.

Cool compresses — a cold washcloth may also be soothing to affected areas


When should I take my child to the pediatrician?

Any time your child has a rash that you’re not sure about or is making your child very uncomfortable, it is a good idea to call your child’s pediatrician. Your doctor may recommend some of the above measures and perhaps an oral antihistamine like diphenhydramine (Benadryl) in select older children. Sometimes a poison ivy rash can be infected, particularly if there is a lot of scratching going on. If the rash is getting worse or not getting any better, or if your child has a rash near the eyes or on the face, or the rash affects large areas of the body, call your child’s pediatrician. In some of these cases, an antibiotic or oral steroid may be indicated.

If your child has a serious reaction such as swelling, particularly of the face or if eyes become swollen shut, see a doctor right away. If your child has problems breathing or swallowing, go to an ER immediately.

Poison ivy — a scourge to humans and damper on summertime fun. It is also a tasty dinner for a fellow denizen of western PA — our prolific white-tailed deer. Perhaps we need to find a way to put the deer to work for us? In the meantime, wash up well when your kids come in from playing and remember:

“Leaves of three, let them be.”

Poison-ivy has 3 leaflets:


Poison ivy in spring is a reddish color:


Poison Ivy in summer is green, with red tinge sometimes:

Poison ivy berries are typically white, light green or grey and DO contain urushiol:

As a vine, poison ivy in the fall may be orange/yellow/red:


Here is more information from the American Academy of Dermatology.

The U.S. National  Library of Medicine has a nice summary here. 


*** Dr. Trina Peduzzi will be seeing patients at Pediatric Alliance’s Allegheny office on Pittsburgh’s North Side (490 E. North Ave, Suite 207) beginning in August. In the meantime, she is seeing patients in our Bloomfield office. To schedule an appointment, call 412-578-4003. We’re so glad to have Dr. Peduzzi as a member of Pediatric Alliance and contributor to The PediaBlog!