How to deal with poison ivy

Itchy, itchy, itchy. There's no better description for the blisters that pop up — and keep popping up — after a run-in with poison ivy, poison oak or poison sumac. The rash-provoking oil in these plants, called urushiol, rubs off not only on you but also on pets, garden tools and clothes, putting you at risk even if you aren't outdoors. Knowing how to avoid the plants is key, of course. These strategies can protect your skin and, in case of unexpected exposure, help you get rid of the blister-raising oil fast.

Poison ivy, oak and sumac crop up in surprising spots — in flowerpots, along sidewalks or twined in trees and bushes. Know how to recognize them. Visit a local nature centre and ask the naturalist to point out your local itch maker.

Wearing high socks, long pants and a long-sleeved shirt provides a barrier against itch-provoking plants. If you find yourself face to face with these botanicals often (perhaps you've got a dog who loves to chase squirrels through the underbrush), keep an extra pair of pants and a shirt in your car.

In a study of 211 people, 68 percent of those who used a urushiol-blocking lotion before heading outdoors had no rash after exposure to urushiol. Once the oil gets onto your skin, it penetrates the top layer quickly and is difficult to remove, especially if you're far from soap and water. The most common active ingredient in this type of product, bentoquatam, is a clay that stops absorption of urushiol.

Some people claim that urushiol can penetrate latex and rubber (though we don't have confirmation), so wear vinyl gloves when working outdoors. Consider wearing a face mask when mowing or using a trimmer near these plants. And treat dead or dormant plants as if they were alive — they still contain the oils that cause rashes. Never burn poison ivy, oak or sumac; the urushiol can severely irritate your lungs.

Washing with soap will remove any urushiol that hasn't attached itself to skin proteins yet. Even if you've taken emergency measures while outdoors, hopping into the shower or washing off your arms and legs in a sink within an hour after potential exposure can further cut your risk of itchy blisters

If you suspect you've brushed against itch-making plants, wash all clothing, including outerwear, right away. The oil stays potent for months or even years and can trigger a new outbreak if you come in contact with the clothing later on.

Urushiol that's rubbed off on shovels, clippers, balls, boots and other objects can stay potent for at least a year in warm, humid environments and for several years in drier climates. That raises your risk of surprise outbreaks even if you haven't ventured outdoors! Cleaning up with soap and water works, as does a rubdown with rubbing alcohol or a solvent like xylene or acetone

• Once the rash appears, it will be there for a while. An over-the-counter antihistamine like diphenhydramine (Benadryl) can help with the itching.
• Over-the-counter hydrocortisone cream may help in milder cases, but stronger prescription cortisone products provide greater relief.
• Cortisone pills or injections can help control more severe outbreaks.