These unassuming plants can cause problems on your skin. Poison ivy, poison oak and poison sumac all have an oily resin throughout the plant that can create an allergic reaction that lasts for weeks.

"Be aware of your surroundings. If they can, wear higher socks or longer clothing to cover their legs."

Dr. Summer Allen, a Mayo Clinic family physician, says, if you come into contact with a plant like poison ivy, wash the exposed skin right away. Rashes typically appear red, slightly raised or swollen with occasional blisters.

"The hallmark for people is that the intense itching that they will feel from it and almost burning, and then redness on their skin. It can get infected if you itch it, and you open up one of the welts."

The rash typically goes away after a few weeks. Topical treatments include calamine lotion; oatmeal baths; a mixture of baking soda and water; or a cool, wet compress.

And another important tip ...

"Make sure to wash all their clothing."

For the Mayo Clinic News Network, I'm Jason Howland.