Poison Ivy Poison Oak. Poison oak looks similar, but the leaves are larger and more rounded like an oak leaf. They're shiny with smooth or slightly notched edges.
But wash your clothes as soon as you're finished, and rinse your washing machine thoroughly, to be sure all traces of the oil are removed. That may not be realistic if you. The rash does not lie dormant and then reappear in the same spot.
When this oil touches your skin, it often causes an itchy, blistering rash.
The defining feature is that the leaves have a lobed, wavy appearance (also described as scalloped), similar to oak tree leaves, but more subdued.
But poison ivy and poison oak are so common that such methods have not been very effective in eliminating them. Poison ivy plants are common in the western half of US. Also, "be on the lookout for a dull, waxy sheen on the plant," says Parents advisor Jody A.