Charles E. Steiner, D.O.
POISON IVY, POISON OAK & POISON SUMAC
Carefully identify a rash before treating for Poison Ivy, Poison Oak or Poison Sumac. Other conditions can cause clear blisters. If a rash hurts or burns and has clear blisters on a red base, then you may need treatment for the chicken
pox virus. If the rash has clear blisters that don’t itch much, then you may need treatment for bacteria. Erroneous treat-
ments used for Poison Ivy, Poison Oak or Poison Sumac could allow bacterial or viral infections to worsen. If there is
any question about a rash with blisters, see a doctor who can identify the rash.
Blisters caused by exposure to these plants are allergic reactions to Urushiol oil. This oil is very hard to wash off
and can be spread by contact. Thick skin is usually not affected, so you can have the oil on the thick skin of your fingers,
palms and soles of the feet without being aware of it. If the rash is growing, you are still spreading the oil around. The
oil does not have to be picked up directly from plants. It can be carried by smoke, animal hair, hands or other surfaces
like doorknobs, clothing, or shoes. People who are not allergic to poison ivy can still spread the oil to others.
The best treatment is prevention. Learn to recognize these plants so you can remove or avoid them. If you are careful,
you can pull plants by using a large plastic bag to cover for your arm and hand. Avoid direct contact with the plants and
indirect contact from the air from the bag. If you do pull the plants, try to take the roots at the same time. Avoid crushing
the plants, and avoid smoke from burning the plants. Avoid contact with persons who touch or burn these plants. Wash
contaminated tools, shoes or items with isopropyl alcohol.
For decades Africans have eaten Cashews to reduce allergic reactions to poison ivy. Cashews are from the same
plant family and are theorized to suppress the allergic response by being introduced to the immune system as “normal”
during digestion. One group of researchers ran allergy tests on workers before and after they were exposed to cashew
nut shell oil. The allergy response dropped from 68% to 16% after exposure, but the mechanism was not identified.
The dose of roasted cashews to reduce poison ivy reactions is one heaping handful a month from Spring until Septem-
ber. WARNINGS: (1) If you are allergic to nuts or are uncertain about cashew allergy, check for an allergic reaction
by eating one cashew and waiting 2 days before starting treatment. (2) Eating a large amount of cashews may cause an
itchy rash like Poison Ivy, and may raise your cholesterol. (3) Unroasted or uncleaned cashews are more potent and
could be dangerous if you have a severe allergy. Eating a capsule of poison ivy twice a summer or repeated doses
of poison ivy extract also works, but do not attempt to prepare capsules or extracts yourself, since you can get a rash
in the mouth and throat if the capsule has the oil on it. There are reports that Ginko Biloba and Genseng also provide
immunity to poison ivy allergy.
Another treatment is to wash off the Urushiol oil. Immediately wash with lots of water as quickly as possible. It
helps to add detergent, but regular soap just spreads the oil around. Follow this wash with an isopropyl alcohol wash.
Zanfel®, an over-the-counter medication, makes this process easier, and contains strong detergents combined with
mild abrasive and other medications. If you cannot purchase Zanfel® ($30+), you can improve skin cleaning of a
strong detergent by adding a mild abrasive, like cornmeal. Scrub the hands first for 3 minutes with a teaspoon of
abrasive detergent. Do not skip this step since the hands often carry the oil. Then scrub the affected area and the skin
around it for three minutes. Repeat the treatment at least once. Do not return to the woods the same day, since scrub-
bing removes the skin’s protective oil layer..
See your doctor immediately if the rash is near the eyes, covers a large area, or the skin is breaking down. The
doctor can give medications that prevent serious tissue damage and reduce the chance of infection.
Topical antihistamines can stop itching quickly. A topical gel made with Benadryl® is quite effective for the itch,
and is available in 4 oz. bottles over the counter at a reasonable price. Calamine is not effective for most persons.
A “compounding pharmacy” like Gahms Pharmancy in Lucasville Ohio can make creams that are faster and more
effective. C. Steiner, DO 1/07/10