
Poison Ivy turns colors earlier than many other plants along the Front Range of Colorado, making it really easy to spot.
When I was 12 years old, my best friend Ali and I went leaf collecting in October. We found the most beautiful leaves blazing with red, orange, yellow AND purple all on one leaf! They were probably the most beautiful leaves we had ever seen. We meticulously placed our collection in an album and admired our work with great satisfaction. The next day our hands and faces swelled and itched and then we broke out in a terrible oozing rash all over. Those gorgeous leaves we had so proudly collected were poison ivy. Ali’s dad tried to scold us and educate us on the identification of poison ivy, but he kept snickering because he knew we were paying the price for our ignorance and we would NEVER make that mistake again. I was out of school for over a week and had to have steroid injections to bring the swelling down. My face was so swollen you could only see the tip of my nose and my hands were gnarled with knobby, witch-like fingers that bubbled with ooze. The blisters were also on the whites of my eyes and in my mouth and throat. The discomfort was unbearable. UNBEARABLE.
Poison Ivy as an Allergen:
Poison ivy, poison oak, and poison sumac are all plants commonly found in the United States and the resultant rash from contact with these plants is the most common cause of allergic contact dermatitis. They belong to the family of plants known as Anacardiaceae and the genus Toxicodendron (formerly known as “Rhus” which is why the rash from these plants is still sometimes referred to as Rhus dermatitis). Allergic contact dermatitis due to plants (allergic phytodermatitis) is a Type IV Sensitivity Reaction, meaning you have to be exposed to the substance at least once before developing an allergy to it. The oleoresins (milky/resinous sap) found in the Toxicodendron plants are referred to as urushiol. This urushiol is made up of a mixture of chemicals, including a group of haptens called Pentadecylcatechols: these are the specific chemicals within the urushiol that are the sensitizing substances responsible for causing allergic skin reactions from contact with these plants. The rashes from poison ivy, poison oak, and poison sumac will each look identical regardless of which plant caused it because each of those plants contains the same allergens. Interestingly, other plants related to poison ivy that can also cause hypersensitivity reactions include cashew nut trees, mango trees, Japanese lacquer trees, and Brazilian pepper. Unroasted cashew nuts, mango rinds, and furniture lacquer can all cause similar rashes (in older TCM texts, allergic contact dermatitis is actually referred to as “Lacquer Sores”).
The urushiol that contains the allergens in poison ivy can be found in the all parts of the plant: the leaves, the stem, the seeds, the flowers, the berries and the roots. That means you can get a rash from poison ivy AT ANY TIME OF THE YEAR if you come into contact with ANY PART of the plant. Not only that, but you have to wash the urushiol off immediately upon exposure (soap and water just fine): after 10 minutes only 50% of the urushiol will come off, after 30 minutes only 10% will come off, and after an hour you are pretty much screwed because it cannot be removed. So your best bet is to avoid exposure in the first place.
Avoid Exposure:
Being able to clearly identify poison ivy is your key to avoiding it. This resilient plant can take many forms: low ground cover, creeping vine (though it technically isn’t an “ivy”), or tree-like shrub. It is lighter green in spring, dark green in summer, and all sorts of beautiful colors in the autumn. Its leaflets are almond-shaped and grow in groups of three, hence the warning “Leaves of three, leave it be!” Some leaflets will have one or a few notches along their edge, but not always. Often, the leaves will have a sheen to them and they may droop just a little bit. For more info on identifying this poison ivy, check out this Wikipedia article (I rarely consider Wikipedia a reliable source, but this article gives a useful description of the plant and has good photos).
So obviously, to avoid the itchy rash associated with poison ivy, avoid coming into contact with any part of the plant. Urushiol can penetrate damp clothing, so wet clothing will not offer full protection from poison ivy. It is also important to immediately wash any clothing that came into contact with the plant because if you later come into contact with contaminated clothing you can be exposed to the urushiol and still develop a rash. Pet fur is also something to avoid if your dog or cat may have brushed up against poison ivy as the urushiol can be transferred to your skin if you pet them. Do not burn poison ivy (any part of the plant) as particulates in the smoke can carry the urushiol and get to your throat. You CANNOT contract the rash by coming into contact with another person who has poison ivy rash because the blisters do NOT contain urushiol.
Although we are talking about poison ivy, it is worth mentioning that you should also avoid eating unroasted cashew nuts and mangoes that are unpeeled as contact with these foods can expose your lips to the urushiol from those plants.
Clinical Presentation:
Depending on previous sensitization, the poison ivy rash can appear as quickly as 8 hours after contact with the plant or as long as 12 days later. New lesions can continue to appear for more than a week after the initial rash symptoms develop (this is not due to spreading the urushiol from scratching blisters as the blisters do not contain any urushiol). Severity of the reaction will vary in the individual based on their level of sensitization, how much urushiol contacted the skin, and where the urushiol contacted skin (some regions of the skin are simply more sensitive). Linear lesions are the telltale signs of poison ivy rash because they form when the skin brushes against a leaf, drawing it along the skin. Linear trails of blisters can also be formed when the skin is scratched while the urushiol is still on the skin and thus gets spread along in a line. If a person brushes up against animal fur that has the urushiol on it then the rash tends to form in a more diffuse pattern. (Or if you inadvertently collect the leaves and carry them around for a while you will get the rash EVERYWHERE!).
Usually the rash starts with itching before any redness or blisters appear. Itching can be very intense. If only a small amount of urushiol contacted the skin, then it may only develop some minor erythema (redness and inflammation). But larger quantities of the urushiol can lead to severe vesiculation (lots of blisters filled with clear fluid). Scratching can lead to secondary infection of the lesions so try not to scratch even though it itches like crazy! Blisters can become crusty after rupturing. Large blisters can be drained but be sure not to rip off the top layer of the blister. In severe cases, hemorrhagic blister can form (blood in the blisters).
Home Treatment:
Once the allergic substance is removed from contact with the body, allergic phytodermatitis (allergic contact dermatitis due to plants) will usually resolve within 2 weeks all on its own. But the discomfort from such rashes is worth treating to reduce the intensity of symptoms and to possible decrease the duration of the rash. Home remedies that offer some soothing relief from itching and inflammation include cool baths with colloidal oatmeal (Aveeno) and the application of cold, wet compresses. Cold compresses can be applied for 20 to 30 minutes several times per day as necessary to control symptoms for the first few days. Calamine or Caladryl lotion can be applied but extended use can lead to over-drying of the skin. I prefer using paste made from French Green Clay (often available for purchase in health food stores). Mix the green clay with enough water to form a paste the consistency of paint (not as thick as mud or it will be too difficult to spread on, but so watery as to drip while you are applying it). Let it dry completely (about 10 to 15 minutes) before soaking it off in a cool bath; DO NOT SCRUB IT OFF. Scrubbing may feel very satisfying in the moment, but it will irritate the skin and worsen the inflammation.
Natural TCM Treatments:
Acupuncture: Both acupuncture and Chinese herbs are helpful to reduce the symptoms of itching and inflammation. For the practitioner, acupuncture points to choose from include Bai Chong Wo, LI 11, LI 4, TW 2, SP 10, SP 6, BL 40Ying-Spring points along affected channels, or bleeding Jing-Well points along affected channels. I really like connecting SP 10 to SP 6 with electro-stim to help reduce itching and redness for these kinds of rashes. Plum blossom tapping around the edges of lesions can reduce itching but do not be too aggressive with it.
Internal Herbal Formula: The main TCM diagnosis for poison ivy is Wind Damp Heat with Heat Toxins. The Treatment Principal is to Dispel Wind, Stop Itching, Clear Heat, Dry Damp and Resolve Toxins. I think herbs are great to treat poison ivy and my patent formula of choice is Xiao Feng San to control itching. The patent form will work well, but if there are many blisters you may choose to prescribe granules so you can add more herbs to Dry Damp and Resolve Toxins to make it even more effective. [See comments below for additional TCM Differentiation and treatments]
Di’s Poison Ivy Formula: (For Acute Symptoms of Itching with Fluid-filled Vesicles)
Ku Shen 9 grams Huang Bai 9 g Shi Gao 15 g Fang Feng 9 g Bai Xian Pi 9 g Xuan Shen 6 g Cang Zhu 6 gIf itching is really severe, also add Bai Ji Li and Chan Tui. If lesions are really weeping, add Di Fu Zi. If the rash is mostly on the upper body/face, add Sheng Ma. For children who can’t stop scratching, add Zi Hua Di Ding to reduce risk of secondary bacterial infection in the lesions.
External Treatment: You can take the above internal formula and use it as a cold compress. Either make the decoction and let it cool or use powdered raw herbs (not concentrated granules) to make a tea. Steep a clean cloth in the cooled tea/decoction and apply for 20 minutes at a time, 3 times per day to the affected areas. You can also make an herbal paste. I like adding Qing Dai and Shi Gao to a little bit of French Green Clay (cosmetic clay). Add enough water to form a paste the consistency of paint and spread it on the lesions (be careful – it may temporarily stain fabric). Allow to dry fully before rinsing off. Rinse off in a cool shower or bath – do NOT try scrubbing the dried paste off as this will aggravate the already irritated skin instead of helping to ease symptoms.
Have a good home remedy for poison ivy that you’d like to share? Leave a comment and share your story below.





Great recommendations! We have Poison Oak here which I treat internally with Yin Qiao San (if you can believe it) works like a charm and is easy to find too. I had an east coast friedn who got PIvey and it worked on that too.
Yes, I should have mentioned the use of Yin Chiao San or Yin Chiao Chieh Tu Pian. It is most appropriate for the TCM differentiation of Wind Heat. For poison ivy, this is the stage when there is much itching and redness but not yet many vesicles. It can be quite effective especially if the patient takes it immediately, at the VERY FIRST signs of rash. It works along the same idea as treating chicken pox – you can’t stop the reaction, but you can speed it up by pushing it out faster. We have poison oak here in Colorado, too, though it is less common than poison ivy. The rash (and its treatment) are exactly the same regardless of which plant was the culprit.
PS and gnarly photos, make me itchy looking at them!
Me, too!
Thanks for the education. I had no idea that we had poison ivy (or poison oak) in Colorado. Now I know what to look for. As the old GI Joe cartoons said, “And knowing is half the battle!”
Grey Rock (in the Poudre Canyon) has tons of poison ivy along the lower part of the trail. It tends to thrive in areas where there is disturbance by humans.
Wow! What a fascinating article! I hate poison ivy!
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