About Poison Ivy: The Facts
Poison ivy is a common wild plant that causes an extremely irritating allergic reaction when touched or brushed against. Exposure to it may result in what doctors call contact dermatitis - a violent blistering rash that spreads over the skin in the area touched by the plant. In severe cases, this rash can develop into extremely painful, swollen areas of skin filled with fluid.
A poison ivy rash usually appears within two days after exposure, peaks after five days, and begins to fade after a week or ten days. While some people can become exposed and suffer little or no effect, being totally immune to poison ivy is unlikely. People who seem immune at one time and place may have an intense reaction the next time they encounter the plant. Poison ivy has two similarly nasty relatives, poison oak and poison sumac.