Poison Ivy: herein lies the rub

We’re well into the poison ivy season at Village Health and I’ve been wanting to review what we all need to know in the event that persistent itch and classic pink, course “sandpaper” rash appears on our limbs, trunk or face.

A quick overview: for the purposes of this discussion, poison ivy, oak and sumac are part of the “Toxicodendron” group of plants and are all pretty similar as far as diagnosis and treatment of the rash is concerned. They all produce a “contact dermatitis”, which is a type of allergic reaction on the skin and it affects well over half of the population. One of the myths people have about this condition is that it is contagious. Not true. Within the first several minutes of contact with the skin the irritant chemical from the poison ivy plant (known as Urushiol) is essentially “tatooed” into your skin and does not transfer to others. So people staying home from work and school for a case of poison ivy is entirely unnecessary.

Although it seems contrary to our experience, neither is poison ivy transferrable from one part of one’s body to another — except in the first few minutes before the oil bonds with the skin’s proteins (or is washed off). The reason it seems to move from an arm to a leg to one’s face, etc. is because there is often a lag time for different exposed areas of the body to mount an allergic response. So when the rash appears on one part of the body, we can expect to see it appear in other exposed areas too over the next few days, but that’s not because it’s “spreading”.

At Village Health our treatment usually consists of either topical prescription steroids (of the “very high potency” strength. OTC Hydrocortisone is not effective) or oral steroids for at least a week or longer — often in a tapering dose. The topicals work great for small areas of afflicted skin, whereas the oral — or injectable in severe cases — form of steroid preparations are used for more extensive rashes. We educate the patient that poison ivy is a roughly 2-3 week ordeal and that the treatment is primarily designed to decrease the severity of symptoms but will not shorten the duration of the condition. Also remember that scratching or rubbing the rash can break down the skin and cause Cellulitis, a serious bacterial skin infection that is a frequent complication of poion ivy. Painful, hot, swollen skin at the site of the rash should prompt a visit to the doctor as soon as possible. Don’t wait for fevers, chills and pink streaks going up the arm.

Prevention is the best treatment strategy of all and involves identifying the plants (as they say, “leaves of three, let them be”) and steering clear of them. Go to Google > Images and type in “poison ivy” for a quick review of these plants’ appearance. If you must work around weeds then be aware that Vinyl gloves work and rubber gloves may not. Any kind of clothing is better than exposed skin. Note well that heavy outdoor work in summer produces sweat, which transfers the oils around during the first 10-20 minutes after exposure. But if one can thoroughly wash off the oils with copious amounts of soap and water within the first 10 minutes there is an excellent chance of preventing an attack. If there is no water source present at your work site, bring 2 spray bottles — one with a little liquid soap added and one with plain water for rinsing and a few clean towels as well.

Also beware of Toxicodendron oils on your pet’s fur. Many patients present to Village Health with facial, neck and arm rashes after hugging their dog returning from a romp in the woods. Keep in mind that these oils will stay potent for up to 6 months on inanimate objects such as work gloves, clothes and tools. We’ve seen patients in December with poison ivy after contact with yard tools. All of the above should be washed thoroughly after exposure to plants.

Good luck out there and have a safe, itch-free summer!