Diagnosis of Poison Ivy, Poison Oak & Poison Sumac
Diagnosis of poison ivy, poison oak, or poison sumac often is made on the basis of physical examination. In most cases, recent exposure to the poisonous plant, followed by observance of the characteristic rash is enough to make a definitive diagnosis.
Because poisonous plants can cause symptoms that are similar to other skin conditions, a physician should be consulted. Physicians examine the area(s) of the body affected by the rash (called distribution) and the type, shape, and arrangement of the blisters.