Wyndham Wisdom

TRAVEL HEALTH: POISONOUS PLANTS

Tips on avoiding poison oak, ivy and sumac, and soothing a rash

By Hannah Wallace

 

Spring is made for spending time outdoors. But watch out for poison ivy, poison oak and poison sumac--all of which release a rash-causing resin called urushiol. We spoke to Dawn Davis, M.D., a dermatologist at the Mayo Clinic, and Steven Foster, co-author of the Peterson Field Guide to Venomous Animals and Poisonous Plants, for tips on avoiding these plants and soothing a rash should you encounter one.

HOW TO AVOID
The best way to protect yourself is to be able to identify the plants. For poison oak and ivy, Dr. Davis teaches younger patients the rhyme "Leaves of three, let it be." The far more virulent poison sumac doesn't follow that formula; it has 7 to 13 leaves per stem.

Wear long pants, long-sleeved shirts and socks when heading into the woods. Davis recommends applying a barrier lotion such as bentoquatam* (sold as Ivy Block at Drugstore.com; $10) to exposed areas. "It stops the absorption of the oil into the skin," says Davis.

Since urushiol oil remains active on inanimate objects, be sure to wash any clothing and shoes that might have come in contact with poisonous plants. Pets should be thoroughly bathed. "You can get poison ivy indirectly from a cat or dog," cautions Davis.

When you're collecting firewood, avoid branches with "aerial rootlets"--a caterpillar-like vine that's likely to be poison ivy, cautions herbalist Steven Foster. Burning poisonous plants can spread the urushiol via smoke, which might cause a rash when it blows onto your skin. (Breathing this smoke is especially dangerous; it can cause respiratory difficulty and even severe blistering in the airways.) 

HOW TO TREAT
Soaps containing pine tar and jewelweed help to dissolve the oil from the urushiol, says Davis. Though there's not enough evidence that jewelweed relieves itching, Davis concedes that these soaps do work as emollients to calm the skin. One to try is Burt's Bees Poison Ivy Soap ($8 at Burtsbees.com).

To help quell the itching, Davis suggests soaking in a bath with oatmeal or baking soda. "These alter the pH of the water," explains Davis, making it more basic--to match the pH of the skin. Use a half-cup of either for a full tub of water, or a quarter cup for a half tub. 

Once you dry off, apply either calamine lotion, which is best for mild to moderate pain, according to Davis, or a topical steroid such as hydrocortisone cream for more severe pain. 

Many who are suffering from urushiol-related rashes turn to home remedies such as plain yogurt. "I can't prove that yogurt works," says Davis, "but a lot of people put it on to soothe the skin, and there's nothing wrong with that. Yogurt has lipids in it--plus, it's cool and it's usually in everybody's refrigerator." 

Poison Ivy
Typically a climbing vine on the East Coast and a low shrub in the western United States. Remember: Leaves of three, let it be.

Poison Oak
Mostly concentrated along the West Coast and in the Southeast. The "leaves of three" mantra applies here as well.

Poison Sumac
This plant generally grows east of the Rockies. It's particularly abundant in boggy areas and along the Mississippi River.

*Consult your physician before taking any medication, and use all medications as directed.