Poison ivy, poison oak, and poison sumac are three plants notorious for causing itchy, uncomfortable rashes that can turn a pleasant outdoor experience into a nightmare.

Poison oak rash is an allergic reaction to the leaves or stems of the western poison oak plant (Toxicodendron diversilobum). Home remedies and medical treatments can help manage symptoms.

But poison oak may have more than three leaves, and depending on the season, species and local environment, plants can vary. All parts of the plant, including roots, can cause an allergic reaction ...