Contact with the poison ivy, oak, or sumac plants causes a rash (allergic contact dermatitis). The rash is caused by contact with the oil (urushiol) in these plants. Urushiol is an allergen, so the rash is actually an allergic reaction to the oil in these plants.
You may be more or less sensitive to the plants than other people. A more sensitive person will have a more severe reaction and will react after minimal contact with the oil.
The degree of sensitivity to poison ivy, oak, or sumac is affected by:
|Primary Medical Reviewer||William H. Blahd, Jr., MD, FACEP - Emergency Medicine|
|Specialist Medical Reviewer||H. Michael O'Connor, MD - Emergency Medicine|
|Last Revised||August 30, 2011|