Poison oak rash is an itching, red rash with raised bumps and, in some cases, blisters that is caused from coming into contact with a poison oak plant. The rash is caused by an allergic reaction to the urushiol oil in the plant, according to WebMD.
An individual can get this rash by either directly touching any part of the plant, even if it is dead, or by touching something else that has touched the plant. Some may experience a severe allergy to poison oak and have symptoms such as trouble breathing, swelling of the face, neck or genitals and large, widespread blisters. If a severe reaction occurs, the patient should see a doctor for treatment. Treatments for the mild rash include soaking the area in cold water, applying a wet washcloth, using calamine lotion and avoiding scratching it. The rash should clear up on its own in 10 days to three weeks, according to WebMD.