Poison oak is a plant found in many states of the United States. It mainly causes allergic reaction to skin after coming in contact with the plant. You can notice the skin rash within 24 to 48 hours of contact. Symptoms can be skin rash, itching, burning and a stinging sensation. You can try over-the-counter medications with your doctor’s advice. Don’t neglect these symptoms. Visit I and My Doctors Clinic as early as possible.