This is a handy way to avoid most poisonous plants when camping and hiking. And remember that poison oak and poison ivy are located even in some relatively urban areas.
According to the American Academy of Dermatology, the saying “leaves of three, beware of me” can help identify poison ivy and oak, a more accurate saying is “leaflets of three, beware of me.” Each leaf on poison ivy and poison oak has three smaller leaflets. The middle leaflet has a longer stalk than the two on the sides.
Contact with a poisonous plant can lead to a nasty, itchy rash. The best way to limit the spread to fellow campers is to isolate the clothing you were wearing at the time in a garbage bag and shower immediately. A bath will just move the oils that cause the rash around and spread it to other parts of your body, so a shower is preferred. This won’t prevent a rash if you’ve had significant contact, but will help prevent the spread to others.
Treatment of a mild case can be solved with a cool shower and some over-the-counter medicine like Tecnu, Caldryl Clear or other itch relief lotion. An oatmeal bath can also sooth the itch. More advanced cases can require a trip to a doctor and a prescription medication to reduce the itching and swelling.