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OUTDOORS: Dreaded poison ivy causing rash of problems

Just like black flies, mosquitoes, deer flies, and hornets, poison ivy is as much a rite of summer as high temperatures and sunshine, says columnist
The dreaded poison ivy is shown above. Beware this rite of summer, columnist warns.

Anybody else had their first seasonal case of poison ivy rash? What, just me? Serves me right, grappling on the ground, tying up a bundle of phragmites reed, with my bare hands, knowing darn well there was poison ivy growing there. Ah well, at least it was just a mild case, this time.

Like many people (about 75 per cent of the population) I am susceptible to the oil within the sap of this plant, and have had the wicked skin rash several times to prove it.

So what might I share with you about poison ivy that you don’t already know? 

First up, let’s get the poison oak discussion out of the way. To encounter poison oak, you have to go to British Columbia, south B.C. in fact, or the Pacific States. It does not grow in Ontario. I don’t care what Uncle Bill’s friend at the pub claims ... it does not grow in Ontario. Unless you have recently been rooting among the roots of B.C. plants, you do not have to worry about it here. 

And then there’s poison sumac, which does indeed grow in Ontario. But sparsely. And only in wetlands. In north Simcoe County I know of only two sites, Wye Marsh and Tiny Marsh, and each of these stations had like three shrubs. Not an everyday occurrence when you are out dog-walking. So chill on the poison sumac drama.

And now there comes the time to discuss the main character, the true poison ivy. This plant is actually a woody species, not a herbaceous flower. Usually between ankle and knee height, it can be found growing both in thick patches and as a sparsely scattered plant. It loves a limestone base as much as a sandy soil area, so it’s, like, EVERYWHERE!

The chemical within the plant that causes us grief is called urushiol (you-ROO-shee-ol). As it travels within the sap, it is present in the leaves, fruits, stems and roots. All year long ... remember that. 

And another fun thing about urushiol is that it can remain active for five years after the death of the plant. That not only includes old roots and fruits, but if it’s on a shovel handle or boot lace the oil can still cause you grief should you use this equipment months or years later.

The sap has to physically bond with your skin to cause the dermatitis. While not an immediate reaction, usually within 48 hours it will have penetrated the epidural layer and begun a red, itchy reaction. Hint: wash with isopropyl alcohol or cool to warm water and soap immediately after you think you’ve had contact. Do not use hot water as that speeds up the oil-skin bonding process. 

Pets (that means you, Fido) rarely get poison ivy but can carry the oil from the plant to you on their fur. Yet another good reason to keep Fido and his ilk on a short lead while walking in the woods. No doubt you nowadays perform an intensive tick check of Fido after every walk, so if the urushiol is there, now you’ve got it, too.

Some research has found that people who come in contact with poison ivy will not react or get the rash ... but the second time, welcome to Club Itchy. A couple of hot rumours going around are that dark-skinned people do not get the rash, or red-haired light-skinned people. Hogwash! If you are a human of some shape or form, you are at risk.

However, there does seem to a relation between getting poison ivy rash and reaching puberty. The under-12 crowd tend to wallow in the stuff without care, yet when the adult chemicals within your body kick into gear, the skin tends to become susceptible to urushiol.

A couple of rash facts to ease your anxiety: once the rash shows up and forms those itchy blisters, the watery stuff inside does not contain urushiol, so you cannot spread it or transfer it to another person. Depending on your skin and how much of a dose you got, the rash may appear in one place and a day or two later in another place; it’s not spreading, just taking its time manifesting itself. 

Treating the rash is a topic best left to be discussed between you and your caregiver. Sometimes a simple cortisone cream will help calm the rash, other times you may need a steroidal treatment. No matter what the ‘cure,’ the rash will exist for about 14 days. Main thing is: do not scratch open the blisters, as that creates a wound primed for infection.

So what does this plant look like? No doubt you have heard the saying “leaves of three, let it be.” But this handy description also includes strawberry, virgin’s bower, blue cohosh and about 12 other plants that bear you no ill will. But the three-parted leaf is a first clue.

Next look and determine if the central leaflet is on a stem that is much longer than the two side leaflets. The leaf shape and margin of PI (you can call it that once you are acquainted) is quite variable: leaflet shape may be a simple ovoid or a deeply lobed margin (hence the confusion with poison oak, which, you may recall, does not grow in Ontario). 

Usually a low-growing ground cover, poison ivy can also climb trees like a vine. This growth form is fairly common in the deep south of Ontario but I’ve encountered PI vines along the Black River, out past Washago way.

The good news about PI is that wildlife species love to eat the dry yellow fruits: deer, ruffed grouse, rabbits and hares, wood thrushes and chipmunks all dine on these fruits in the autumn with no ill effects. 

The bad news is that other research has shown that PI loves carbon in the air, and as we are continuing to emit carbon dioxide into the atmosphere, the PI plants are gobbling it up and growing stronger, faster. And the warming trend of climate change is also enhancing PI growth. Just so ya know, OK?

Just like black flies, mosquitoes, deer flies, and hornets, poison ivy is a rite of summer. So get outside and enjoy our natural environment ... but maybe slap on some sunscreen, tick repellent, a long-sleeved shirt, long pants, and a broad-brimmed hat. There you go, all set for some summertime fun!