This condition is caused when the skin is exposed to the sun or a tanning bed after a long absence from ultraviolet rays.  These plants produce a substance that triggers skin reactions. This product prevents the absorption of the allergen produced by the plant.
Use sunscreen and increase sun exposure slowly over time. Poison Ivy and Oak
 Avoid any plants whose leaves cluster in 3s. Use an over-the-counter skin block during high-risk activities such as camping and hiking.