FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

POISON IVY "OOZE" DOESN'T SPREAD RASH

Question: Every summer I get poison ivy even though I try to avoid it. I get a rash and blisters, and when the blisters break, the poison ivy spreads to more areas. What can I do to avoid poison ivy this summer? What can I do the help clear it up if or, more likely, when I get it?

Answer: Poison ivy has the potential to cause itchy blisters in about 85 percent of those who are exposed to it. This is also true of its close relatives, poison oak and poison sumac. You are obviously one of the unlucky majority instead of the fortunate 15 percent.

These poison-plant rashes are caused by a sticky chemical, urushiol, that is found within the plant's leaves, stems and roots. Usually one gets urushiol on the skin by directly touching the plant. However, urushiol can also be carried on the fur of pets, garden tools, golf balls or anything else that comes in contact with a broken plant. It is also released when the plant is burnt, so exposure to the smoke can be as dangerous as rubbing against the leaves.

Once the chemical comes in contact with the skin, regardless of the way it gets there, it begins to penetrate in a matter of minutes. After this, it takes from 12 hours to as long as several days for the allergic reaction we identify as poison ivy to appear. It develops with redness and swelling, followed by itchy blisters.

Contrary to your belief, which is also held by many others, poison ivy can't be spread from the "oozing" liquid in the blisters. This liquid is your body's own fluid, produced as a reaction to urushiol. It does not contain urushiol and, therefore, can't spread poison ivy.

But as you know, poison ivy can be spread, and here's how it usually happens: urushiol gets on the victim's hands, and by touching another part of his, her or another person's body, the chemical is transferred to that area as well. The area that has the greatest exposure to the urushiol will usually break out first with a rash and blisters. Areas that have thick skin or less urushiol on them will become inflamed a day or two later, giving the impression that the poison ivy was spread from the first group of blisters. That's the reason poison ivy tends to turn up all over the body, even though the plants generally only come in contact with exposed areas of the skin.

Now to address your question about prevention. Avoiding the offending plants is the only sure way. If, however, you suspect that you have been in contact with poison ivy or one of its cousins, the first thing to do is thoroughly wash the exposed areas with soap and water. The soap is essential because water alone will not remove the urushiol. If more than 20 minutes have lapsed since the exposure, washing may not keep the initial rash from developing, but it can prevent you from spreading it further.

If your clothing has come in contact with the sticky sap containing the urushiol, it should be washed promptly. Handle the clothes carefully, preferably with vinyl gloves, to prevent any more skin contact with the sap.

If you have already gotten poison ivy, here are a few suggestion that may shorten the course of the rash and itching. Mild cases of poison ivy may require no more than a wet compress or soaking in cold water or Burrow's solution to relieve the itching. Calamine lotion may be soothing, too, but avoid other home remedies. They often worsen the damage to the already irritated skin.

There are several non-prescription medications on the market, like calamine lotion, that can dry up blisters. However, the 1 percent hydrocortisone creams advertised as good treatment for bites and itching are not strong enough to be of any value in treating a poison ivy rash. Severe cases particularly those involving the face, eyes, hands, or genitals should be referred to a physician for proper care.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.