Here on the Central Coast, poison oak is rampant. It grows like a weed, and can be found along stream beds and hiking paths, on hillsides, and even in your own backyard. Poison oak's cousins, found farther east, are poison ivy and poison summac—few of us have escaped its wrath.
Experts estimate that about 70% of the population is sensitive to the oils found in the sap of this noxious plant family. Thus you face the likelihood that you or a family member will return home from a romp in the woods with an intensely itchy, oozing rash that can take a week or two to resolve. Haven't seen it yet? Just wait. Your time will come.
Myths abound regarding the plants themselves, the rashes they cause, and the most effective treatments. Here are a few common misconceptions (keep in mind that all three plants share the same characteristics).
Myth: Poison Ivy rash is contagious.
The rash is an inflammatory reaction to the oil (called urushiol) found within the plant. It is not caused by an infectious agent such as a virus or bacteria. As a result, poison oak rashes cannot be passed or spread to others. The rash is not contagious, nor is the fluid from the weeping sores. Be aware however, that the plant oils can be spread indirectly through clothing or the fur of pets.
Myth: Dead plants are safe.
Not so. Urushoil, the offending oil in poison oak, can stay active for years after the plant dies. So if poison oak is in the area, be just as careful walking through dead brush as you would among live bushes. Also be cautious when burning plants. The oil becomes aerosolized into the smoke when poison ivy is burned, and can cause significant reactions to those who happen to breathe it into their lungs.
Myth: Scratching poison oak blisters will spread the rash.
Poison oak rashes often appear as weeping, oozing blisters that are extremely itchy. Scratching these blisters, and thereby spreading the fluid to other areas on your body does not cause new blisters or rashes. One reason this myth keeps re-appearing is the unusual progression of the rash. Depending on the amount of urusoil contact, and the area of the body affected, poison oak rashes can break out from 1-7 days from the time of contact. So naturally, as new areas develop a rash, we mistakenly assume that we are spreading the rash.
Myth: Once you are allergic, you will always be allergic.
As our immune system ages, allergic reactions, which are simply an over-reaction to a foreign agent, tend to lessen. Children, who may have been exquisitely sensitive to poison ivy when young, will tolerate exposure much better as they get older.
Myth: Once you come in contact with poison oak, there is nothing you can do to stop from developing the rash.
Not true. Here are a few steps you can take.
Remove all clothing, shoes, and hats that may have come in contact with the oil.
Cleanse the areas that may have come in contact with poison oak with plain soap and water. Pay special attention to the palms, whose thick skin slows binding of the urusoil (but allows the oil to be spread to other areas). Be aware that after binding has taken place (within 5 minutes to 2 hours) washing with soap and water will not remove it from your skin.
Medicate affected areas with Zanfel, the only product proven to eliminate urusoil from the skin after binding has taken place. Zanfel is a body wash available over-the-counter. Common remedies like calamine lotion may be soothing but will not displace the oil from the skin. Avoid topical creams that contain antihistamines (benadryl) or anesthetics (benzocaine)—they can actually worsen the rash, and most medical experts doubt their effectiveness.
No scratching! Bacteria can be forced into open sores and cause a secondary infection. Scratching will also prolong the rash and symptoms. Try putting socks on a child's hands at night to prevent them from scratching in their sleep.
Consult a physician if the rash is severe, or you suspect a secondary infection. Working in a college town near several poison oak laden hiking trails, my ER is often populated by miserable, itchy students in dire need of relief. I will often prescribe steroids, given orally or by injection, which will decrease the severity of the symptoms, but attach certain risks as well. Other medications can help with itching and getting some sleep.
Of course the best course regarding poison oak is prevention. Learn which of the poison plants live in your area, and how to identify them. Then keep yourself and your family far, far away. A moment of prevention is worth a pound of itching and oozing.
