Poison Oak and Poison Ivy

By Andy Kerr

Poison oak (Toxicodendron diversilobum) is found in western Oregon (west of the Cascade Crest) and can be either a bush or climbing vine.

Rydberg's poison ivy (T. rydbergii) frequents stream bottoms in eastern Oregon.

Both are found only below 4,000 feet elevation. Both are members of the cashew family and prefer sunshine, but can do without; prefer drier soils, but can tolerate wetter soils; and prefer disturbed ground, but can live elsewhere. Although essentially the same plant, the shape of the leaflets differentiates poison oak and ivy.

Learning to identify the plants is the single most effective thing you can do to avoid later troubles. It is more than knowing and heeding "leaflets of three, leave it be," though it is a start. There can be up to 11 compound leaflets. Know the plant by leaf and plant shape.

The next thing to do is to dress properly to avoid contact with the plant. Wear real shoes, not open sandals. Wear long pants and not shorts.

IvyBlock, a barrier cream, spread on the skin before exposure, contains quaternium-18 bentonite, a chemical that bonds with urushiol, so it cannot bond w/ the skin. The cream prevents reaction 68% of the time and reactions are likely to be less. However, it cannot take place of prevention.

The poison in these poison plants is the oil urushiol ("yoo-ROO-she-ol" or "oo-ROO-she-ol") which flows throughout the leaves, stems, roots and skin of the berries, but not in the flowers, pollen or dried leaves that have fallen naturally from the plant. It is a very powerful oil: two micrograms (about two-millionth of two tablespoons) is enough to cause a reaction in most humans. You cannot be exposed through the air, though you can by coming in contact with urushiol in smoke and soot. You do not have to have contact with the plant itself, but only with things that have contacted the plant, such as clothes (including those of others that you are washing) or pets.

Only 15% of the population are truly immune. Eating leaves or other such things will not cause immunity. If you reach adulthood with out a reaction, your chances drop from 85% to 50%.

If you suspect that you have been exposed, quick preventative actions can avoid dermatitis (rash and blisters).

Urushiol starts to chemically bond with the skin within five to ten minutes. However, do not try to wash it off immediately if more exposure is likely. Wait until you're out of the woods as washing also removes good oils on your skin that somewhat protect you from urushiol.

The best treatment for exposure to urushiol is rubbing alcohol (in a pinch vodka or gin works, but only if you rub on, not drink it), which is a solvent that neutralizes the urushiol. If used within four hours of exposure, it will leach urushiol out of the skin. (Do not use rubbing alcohol after the rash begins to appear, as it will just further irritate already irritated the skin.).

Drench a cloth in rubbing alcohol (I have used gin work in a pinch and result was effective but soberting) and pass over the skin. Then take a shower with copious amounts of tepid water (hot water opens up the pores). You can soap, but only with plenty of water; otherwise you're moving the urushiol around. Water does not dissolve urushiol, but it does dilute it. The use of harsher soaps has no more effect on urushiol than regular soap and can irritate the skin.

Be sure to isolate exposed clothing until they can be washed or risk re-contact with urushiol. Regular washing does the trick.

If rashes and blisters do erupt, it is often associated with oozing and weepy sores and always with a pernicious itch. When urushiol bonds with the skin, it is chemically changed and no longer urushiol. The urushiol-induced ooze is not contagious to the oozer or others. The ooze is just plasma and contains no urushiol.

Seventy-five per cent of cases can be treated at home. Reach for the calamine to dry weepy sores and reduce the itch. Do not use Caladryl, as it contains the antihistamine benadryl, which provides little relief and can make you sensitive to benadryl, perhaps causing allergic reactions later when you really need the stuff. Over-the-counter topical cortisone creams can relieve itch.

Very hot showers often cause relief that last for hours, as they draw histamines, the cause of the itching, to and away from the skin surface.

If you break out on large amounts of your body, or your face or genitals, a trip to the doctor is advised, where you'll probably be given corticosteroids, which can have some side effects.

While you are recovering, a very good book to read is Nature's Revenge The Secrets of Poison Ivy, Poison Oak, Poison Sumac, and Their Remedies, by Susan Carol Hauser. Knowledge can minimize itching.