Allergens: Poison Ivy
is poison ivy?
There are three native
American plants that collectively may be called poison ivy: poison
ivy, poison oak, and poison sumac. These plants cause an allergic reaction
in nearly 85 percent of the population.
causes the allergic reaction?
The resin in the plants
contains an oily substance called urushiol. Urushiol is easily
transferred from the plants to other objects, including tools and animals.
This chemical can remain active for a year or longer.
is the allergic reaction to poison ivy?
The reaction is usually
contact dermatitis, which may occur several hours, days, or even weeks
after exposure. The dermatitis is characterized by a rash followed by
bumps and blisters that itch. Sometimes swelling occurs in the area of
contact. Eventually, the blisters break, ooze, then crust over.