This article is for those of you who’ve never had it, or had it once or twice, and for the people who ended up at the doctor’s office because of it. I want to motivate you to learn to recognize the plant, because the best treatment for its nasty rash is PREVENTION. Avoid contact with the plant, and avoid contact with things that have touched the plant, and you limit your risk. Nobody wants the rash. Itching is at least as maddening as pain.
If you are not quite sure what it looks like, you won’t learn it from pictures or articles. You have to learn it in the field. Ask about it when you’re out in the wilds with people who know the plant. We can point it out to you in all its forms.
You can limit exposure by wearing clothing that covers your skin. And you can coat your skin with tecnu or bentoquatam to prevent the urushiol from sticking to you. Tecnu is a product that solvates the oil but it contains propylene glycol (radiator coolant) which I’d rather not introduce to the environment. Bentoquatam is a product made from bentonite clay that forms a coat on your skin to block the oil from getting on you. It is probably more environmentally friendly.
The leaves of both poison oak and ivy are shiny when they are new and become duller over time. Both have “leaves of three”, meaning there are three leaflets on each stem that together comprise the leaf. Both have some variability in the leaf shape, with edges that range from toothed to smooth to almost lobed, but the “leaves of three” always fit together in a similar way. The leaves of both turn red in the fall and both can have white fruit that remains on the plant after the leaves have fallen. Both like to grow along rivers and streams and forested trails, in exactly the terrain frequented by boaters. The saying “leaves of three, let it be; berries white, take flight” applies to both.
There’s a debate about which plant is more contagious or causes a more severe rash. I have found nothing to shed scientific light on this question, though most people online say oak is worse. They seem equivalent in potency to me personally, and are both to be avoided.
The toxin in both poison oak and ivy is a sticky oil called urushiol. It causes a type of contact dermatitis that an immunologist would call a type 4 delayed hypersensitivity reaction. The rash appears 1-3 days after exposure to the urushiol. The first symptom is an itch, then red bumps form which later become amber fluid-filled pustules. If you scratch open the pustules then you have open wounds which can get infected, complicating the problem. The final stage is the healing of the pustules and wounds, which can take a week or more.
There are a lot of myths about poison ivy/oak, and I’ve listed my top seven here.
Myth 1: The fluid inside the pustules is contagious. This is FALSE. What is contagious is the sticky urushiol oil. The fluid from the pustules is just serous fluid from your body and it is harmless. The oil can stick to your skin, your dog, your walking stick or your shoes, and it “sticks around” until it is washed off with lots of soap. If it is on your skin in one place and you scratch there, then touch somewhere else, you have just introduced the toxin to a new location and unless you wash it off you can look forward to a nice itch starting in about a day.
Myth 2: You have to go get steroids to treat poison ivy. Not so, in fact corticosteroid drugs like prednisone have some nasty side effects and should only be used under doctor’s orders. Most of the time the rash is not so severe and will go away on its own given removal of the toxin and time. After you wash off the urushiol you just need to keep your sanity while the rash runs its itchy course, which takes about a week. You can reduce the immune response that causes the dermatitis by taking lots of vitamin C. If the itch keeps you from sleeping you can take an anti-histamine, but don’t take these every night longterm because they also contribute to dementia.
If it makes you feel any better, you can temporarily kill the itch with cold water. After you’ve scrubbed it with hot soapy water, chill the rash with the coldest water you can get from the tap. After you cool the affected skin, don’t touch it, and it won’t itch for a while.
Myth 3: You can wash the urushiol off with river water. This is debatable because there does seem to be some reduction in future symptoms from vigorous washing in river water after an exposure. Still from what we know about the chemistry of urushiol (a very long and sticky oil molecule), it can stick on the skin until you attack it with either a detergent or a solvent. Fancy soap with moisturizers is less effective for removing the oil than just plain soapy soap. Rubbing alcohol can work for removing the oil but it stings like the devil if you’ve scratched yourself too hard, and you might not want to bathe in it. Brief soaping up like we normally do will not get urushiol off. You have to really scrub it. Use a lot of soap and a wash rag, and scrub every surface especially in nooks like between your fingers. Wash well within 24 hours of an exposure, and follow that up with repeated soapy bathing any time you feel an itch. Wash your clothes and shoes in hot soapy water too. If you get all the urushiol off, you will at least avoid starting new patches.
Myth 5: Scratching does no harm. Actually, the bad news is that scratching makes it worse. First of all, you can spread the toxic oil around your body by scratching. Second, scratching makes it itch more, because it releases more histamine. Third, scratching will open pustules and cause wounds which can get infected with bacteria. It’s best to leave the pustules alone as long as you can, draining them with a pin if they get in the way. Cover them with a bandage to keep the thin skin from coming off until the wound has started healing from underneath. If you’d rather put calamine on it that doesn’t hurt, and it does mark the area not to scratch.
Myth 6: You can get immune to it. Actually it works the opposite way. The more you are exposed to the toxin, the more sensitive you get. You will get the rash faster if you’ve had it before. There are those who say if you eat the first bud of new poison ivy leaf that you see in the spring, that you will be immune. I doubt it, but people say it. As far as I know the only way to remain insensitive to the toxin is to avoid contact with it.
Myth 7: Jewel weed will treat your poison ivy rash. This is definitely false. Someone actually did a study on this. Jewel weed is a pretty orange-flowering plant that grows near water where you also will probably find poison ivy/oak, but it makes no difference in the course of the dermatitis caused by urushiol. We love our folk remedies but this one is unfortunately just a nice story.
This may not seem like an urgent concern, but you don’t have to look far to read stories of people who’ve gotten the poison rash on their face or genitals, which could obviously be very bad. There are also stories of people getting it in their lungs from breathing smoke from fires where it is burning. Severe exposures or reactions do need medical attention. Proper dosing and tapering is essential to manage the negative effects of corticosteroids, so please do not take them at home without seeking a doctor’s opinion. Definitely tell the doctor if you’ve been out in the woods when you get a rash. I have seen three cases so far of city doctors misdiagnosing a poison oak rash as shingles. They are not the same, and you can help the doc get the treatment right by giving them a full and proper history of your rash.