Wednesday, May 11, 2011

Dreaming of poison ivy

By Richard P. Holm M.D.

Every spring through summer I expect a call from a patient of mine after he’s had an exposure to poison ivy. Like 80% of the population, when he touches the plant he breaks out with a miserable blistery and itchy skin reaction. But my friend is so allergic to poison ivy that he gets a rash if he even dreams he’s gone camping.

In this area of the country poison ivy is a very common weed, as it crops up around lakes and streams and on the edge of wooded areas. Normally there are three green or red almond shaped leaves, the side leaflets sometimes have a notch, the middle leaf has a longer stem, stems are hairy without thorns, and there can be small clusters of green or white berries. This might be a freestanding shrub, a trailing ground plant, or come from a rope-like woody and hairy vine, which climbs trees. Remember: leaves of three, let it be; berries white, run in fright; and hairy vine, no friend of mine.

The rash is an allergic reaction humans have from the oil or sap that comes off the fine hairs on the stems, the leaves, and the woody vines, the later of which remain a threat even through the winter.

Once exposed to the oil, there is less than 15 minutes to remove it, and antiseptic rubbing alcohol towelettes are effective, readily available, and cheap. Then rinse this with cold water, followed with a dish detergent cleansing in lukewarm water as hot water too early can spread the toxin. Finally wipe down shoes with rubbing alcohol; wash clothes, and someone not so allergic should wash the dog.

Usually 12 to 48 hours after exposure the allergic skin reaction is a linear, very itchy, blistery rash, which may worsen over days or weeks if not treated. Know that the fluid from blisters is not toxic.

Treatment includes laying on of cool moist washcloths, followed by topical calamine lotion or over-the-counter cortisone cream, and if bad enough, see your doctor for a prednisone prescription.

So if you are dreaming of a camping trip, know what plant to avoid, bring alcohol towelettes, and call the doctor if you get that darn rash.