Post and Courier
October 25, 2014

Know The EnemyWith leaves of three, poison ivy lurks in rain-fueled gardens and woodlands

Posted: 07/21/2013 12:01 a.m.


By Jennifer Berry Hawes

This year, the battle began with mowing a patch of weeds that had grown a bit too cocky in our daily downpours and summer heat.

I didn’t notice my own personal nemesis, Toxicodendron radicans, lurking within the dense foliage.

But it was there, or so I figure.

Because a day or two later, I noticed a little bump on one arm, sort of like a mosquito bite. I knew better. I’ve met this enemy before.

The next day, one bump became a row. Then blisters that morphed into multifronted invasions of blisters that oozed and spread and ... did I mention the itch?

There is an insanity inflicted on those who suffer Eastern poison ivy sensitivities. It is the insanity of experiencing an itch so severe you want to succumb to the (ill-advised) euphoria of scratching the daylights out of your own skin.

Sadly, I’m in good company.

Up to 85 percent of people suffer some degree of allergic reaction to poison ivy, poison oak or poison sumac. Chances are, you too fear this enemy, he with “leaves of three.”

Know thy enemy

I’m quickly set straight by Robert Polomski, Clemson University faculty and extension horticulturist.

Factoid: They are leaflets of three. Poison ivy has compound leaves with three leaflets each.

Another factoid: Our nemesis isn’t the poison ivy plant itself. The enemy is urushiol, an oil produced by all parts of the plant. It can remain active for a year on dead plant material. It even sticks to pets’ fur, so if you have outdoor pets, they can bring the oil right to you.

When are plants most dangerous? Basically, now.

Urushiol contents are highest in spring and summer. And recent rains and heat have nourished seedlings and supercharged growth.

“Being inundated with all of this rain is helping these plants explode,” Polomski said. “It’s been a banner year.”

Which is not encouraging.

Insidious enemy

It looks so innocuous. Innocent even.

The edges of poison ivy’s characteristic three leaflets vary: smooth, wavy, lobed, serrated or toothed. Leaflets often have a notch that makes them look a bit like green mittens.

A deciduous perennial vine, it grows as ground cover while seeking something vertical. Then, upward it travels, engulfing trees, telephone poles and other structures.

“They’ll grow on almost anything if given a chance,” said Mark Arena, lead Clemson Cooperative Extension agent for Charleston, Berkeley and Dorchester counties.

It spreads as a vine on the surface and with rhizomes underground.

“I’ve seen so many areas, especially abandoned areas, become poison ivy deserts,” Polomski said.

(While poison oak and poison sumac are found in our area, Arena says he rarely sees them.)

Factoid: People often confuse poison ivy with Virginia creeper (Parthenocissus quinquefolia), a native species that looks very similar. However, Virginia creeper has leaflets of five that grow in a circular pattern.

“It’s tragic when people tear it out of the landscape because it’s a really fabulous native plant,” Polomski said.

There’s an old saying that can help with identification: “Don’t be a dope. Stay away from the hairy rope.”

Identify mature poison ivy by its distinctive hairy aerial rootlets. They are reddish and visible after plants lose their leaves.

Shocking factoid: Poison ivy has positive attributes.

A native species, it produces vibrant fall color and small yellowish flowers that grow into white berries. Birds love to eat (and spread) them.

This might be why poison ivy is common on the edges of woody areas and gardens where many birds hang out.

Just last week, I ventured to my back gate to take a few items to our compost pile.

What’s clinging to the fence right there?

Yep, he with leaflets of three.

Seek help if ...

Dr. Jonathan Jennings treats patients for poison ivy reactions year-round at Sewee Internal Medicine in Mount Pleasant.

He warns that if you don’t react to poison ivy now, don’t get cocky. New allergies can appear throughout life.

And once you’ve suffered a reaction, you will continue to do so. The body has cells that, once exposed to an allergen, remain on the prowl for that allergen again — and they have really good memories.

“Every subsequent exposure will be a little more rapid and more profound,” Jennings said.

Reactions can be serious. Call your doctor immediately if you have trouble breathing or a severe cough after exposure to burning weeds, or if you develop a fever or increasing redness around a blister.

Symptoms that might require a less urgent trip to the doctor include swelling, severe itching, severe reactions in the past and a rash that lasts longer than three weeks.

“There’s no reason to suffer through it,” Jennings added.

Doctors typically prescribe topical steroids. In severe cases, patients may need oral steroids. Folks with chronic skin conditions such as eczema and psoriasis should be extra vigilant.

However, most people can kick a reaction using over-the-counter and home remedies that reduce itch to a tolerable level until the reaction subsides.

Scratching blisters doesn’t spread the rash, but it can introduce bacteria that cause infection.

“Your goal is to not cause your body any injury,” Jennings said.

Poison ivy isn’t contagious, although the sight of blisters will keep most people at bay regardless.

Remedy me

If you are exposed to poison ivy, wash the area thoroughly with a strong soap (not a moisturizing one) such as Lava soap or a dish detergent, such as Dawn, that can cut through the oil.

You don’t have much time. Think 30 minutes or less. Or more like 10 minutes if you’re very sensitive.

Poison ivy cleansing agents available at drug stores can help remove the oil if applied within several hours of exposure.

Some folks swear by remedies such as olive oil and jewelweed plants (Impatiens capensis).

But what if you’re too late?

If you spot a reaction, try calamine lotion, hydrocortisone cream or manganese sulfate solution from a drug store.

Other remedies abound.

Oatmeal baths. Salicylic acid. Rubbing alcohol. Vinegar and salt paste. Baking soda and water paste. Buttermilk. Yogurt. Apple cider vinegar. Diluted bleach. Plantain plants (Plantago major).

Arena of Clemson likes to head for an ocean swim — and the relief of salt water.

“Anything to dry it out,” Arena said.

During my most recent affront, I thought of the most drying agent I could find in my home right then. I remembered an over-the-counter acne cleanser with salicylic acid that can transform even the oiliest face into the Kalahari.

I pressed soaked Q-tip after Q-tip onto the worst blisters, avoiding healthy skin around them. I claim no scientific validity, but a day or two later the blisters began to clear.

Good riddance

Critical factoid: Killing a poison ivy plant doesn’t kill its urushiol. The oil can remain active for at least a year on dead plants (and your shoes, clothes, gloves and garden tools).

You are fighting an enemy, even a dead one, that you don’t want to touch. Yet, Polomsky recommends hand-to-hand combat.

Wear gloves, long sleeves, pants, socks and shoes to protect your skin. Even better, take the plastic bags your newspaper comes in, band them above your elbows and use them like gloves. After battle, remove them inside out and toss because they’ll be contaminated with urushiol.

Or, do battle from afar with a garden hoe to sever the rhizome below the soil surface and avoid contact with the plant.

“It’s like handling a hot potato,” Arena cautioned.

First, pull or dig up as much of the plant and roots as possible.

Then cover the area with two to three inches of mulch to help suppress new growth.

It won’t surrender easily.

“The plant will respond by producing new shoots,” Polomski said. “It’s not a one-time deal. You will have to come back again.”

While herbicides are effective, be cautious spraying them near other plants in the garden. They are nonselective and will damage desirable plants as well.

Also, don’t burn the poison ivy. Burning can send urushiol airborne into people’s lungs, eyes and other areas, causing potentially serious reactions.

Dispose with yard waste or, Polomsky prefers, bury poison ivy so it decomposes and renourishes the soil. Just be sure it is dead so you’re not just re-planting it.

And then you’d just be aiding the enemy.



Reach Jennifer Hawes at 937-5563, follow her on Twitter at @JenBerryHawes or subscribe to her at facebook.com/jennifer.b.hawes.