How Common Are Poison Plant Allergies?
Poison ivy, poison oak, and poison sumac are three of the most common causes of allergic contact dermatitis in North America. Some experts estimate that three out of four people are sensitive to the chemical found in these plants, although the degree of sensitivity varies. Some people are very sensitive and will have a quick reaction upon contact with a small amount of urushiol. For those who are less sensitive, exposure to a large amount of urushiol is necessary before a reaction develops. Cases of poison plant allergy occur most frequently during the spring, summer, and early fall when people spend more time outdoors.