The Big Three: Poison Oak, Ivy and Sumac

But pursuing the wonders of nature can also have drawbacks.

In addition to the potential dangers of the sun’s rays and the discomfort of insect bites, outdoor enthusiasts should be aware of the evils of a trio of problematic plants – poison oak, poison ivy and poison sumac.

According to the American Academy of Dermatology in Schaumburg, Ill., the toxic oily resin from the plants are among the country’s most common allergic reactions.

As many as 50 million North Americans are affected per year.

And for those active in the great outdoors, there’s little escape. With the exception of Hawaii, Alaska and some desert areas of Nevada, the weed is prevalent throughout the United States in its three regional varieties:

* Poison oak – A low-lying shrub or small tree or vine with three or five leaflets and clusters of yellow berries, is found in the West and Southwest. The plant’s leaves turn a deep red in the fall.

* Poison ivy – A low-growing shrub or vine with green-yellow flowers and white berries, is dominant east of the Rockies, but also grows in other regions.

* Poison sumac – A tall rangy shrub with 7-13 leaves and cream-colored berries primarily located in the Great Lakes regions and in swamps and bogs east of the Mississippi River.

Although all three plants flourish in the spring and summer, allergic reactions can occur in the fall and winter when the plants’ sticks and vines are mistakeningly used as firewood or in holiday wreaths.

“We get a lot of calls in the winter from people who have think they may have inhaled the toxic oil after they’ve burned their fields,” said a spokesman at the Regional Poison Control Center in Sacramento, Calif. “It can be very dangerous if you get poison oak, ivy or sumac in your lungs. Firefighters are very susceptible.”

The “poison” in each of the three plants is the result of an allergic reaction to urishiol, the colorless or slightly yellow oil that oozes from any cut or crushed part of the plant.

Those sensitive to poison oak, ivy and sumac don’t need to come in contact with the plant to develop the rash. Since urushiol spreads so quickly and can be invisible, it may be carried on animal fur, garden tools, sports equipment, clothes or any other object that comes in contact with the resin.

Once urushiol touches the skin it begins to penetrate. If you’re among the estimated 85 percent of the population sensitive to the sappy substance, a reaction will usually appear within 12-48 hours as a line or a streak of rashes resembling insect bites.

Redness and swelling will begin in a couple of days, with blisters and severe itching lasting from a few days to several weeks. For those with darker-colored skin, small dark spots can remain even after the rash heals.

Potential sensitivity to the three plants is hard to define or categorize. Children are often infected for the first time between ages 8-16 – and often with severe cases that can include swollen eyes and severe fever.

Although any part of the body is susceptible, thicker-skinned areas like the soles of the feet and palms of the hand are often unaffected.

Although sensitivity to the rash can decline with age, adults should not assume they’re immune – even if they never suffered from the rash as children. Fair-skinned people are the most susceptible.

“Prevention is the best cure,” said the Poison Control Center spokesperson. If you know what you’re dealing with and take preventative measures, that’s the best way to avoid the stuff.”

For instance, if you’re hiking, running, bicycling, hunting or enjoying any outdoor activity, be aware of your surroundings. To avoid contact with the plants, wear long pants, long-sleeved shirts, gloves and boots, if possible. Keep your pets from running through poisoned areas. And never burn any of the plants.

However, if you think you may have had contact with poison oak, ivy or sumac, wash all potentially exposed areas with cold running water from a stream, lake or garden hose as soon as possible. If washing is done within 15 minutes after contact, the water can neutralize the sap and prevent it from spreading.

When you return home, wash all clothing outside to prevent resin from transferring to rugs or furniture. Since urushiol can remain active for months, make certain to wash all camping gear or equipment that also may be carry the resin.

If you develop a rash, avoid scratching the blisters. Although the fluid in blisters will not spread the rash, fingernails may carry the resin or germs that could cause an infection.

Successful treatment for the rash varies. While some firefighters have become immune by taking long-term prescription medication that contains the plants’ extract, this procedure is not recommended for the general public. The tedious process can cause severe cases of the rash and also prompt other side reactions.

In some instances, Hydrocortisone cream as well as Calamine and Caladryl lotions are recommended to help dry oozing lesions. Other over-the-counter products such as rubbing alcohol and Tecnu lotion works well to neutralize the toxins if used within a few hours after contact.