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Poison Ivy (cont.)

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What are the signs and symptoms of the poison ivy, poison ask, and poison sumac rash?

Signs and symptoms are related both to the sensitivity of the individual as well as the severity of exposure. While over half of people are sensitive to poison ivy, oak, or sumac and will react by developing the characteristic rash, about 10%-15% of the population is highly sensitive and may have particularly severe symptoms or develop symptoms after a very mild exposure.

The rash usually starts one or two days after exposure, though the delay between contact and its onset can be longer, up to several days. This may lead to confusion over where the exposure took place. The first signs of the rash are curved lines of red, itchy bumps or blisters. These continue to appear for many days, even up to two to three weeks due to a slow reaction to absorbed urushiols and depending on how much resin touched the skin at a given point. This makes it seem as though the rash is "spreading," although the fluid in blisters is just part of the allergic reaction and contains no chemicals or bacteria. It also makes it appear that there may still be poison ivy in clothes and/or on pets. Although this is theoretically possible, repeated washing of these often produces no improvement.


Poison ivy, oak, or sumac is not contagious, neither from one person to someone else nor from one part of the body to another.

Many references emphasize that animals can carry the poisonous resin. There's no doubt this is true, but its practical significance may be limited. The first sign of poison ivy, after all, is usually a curved line of rash on the skin. Your poison ivy is more likely to have come from a stem or leaf that dragged against the skin, not from your pet.

Medically Reviewed by a Doctor on 9/17/2012

