Poison Ivy

Wash with soap and water to dilute the poison ivy.
To decrease the itching, make a paste of backing soda and water, and apply it to the area.
Antihistamines will also help dull the itch.
Do not scratch the rash, as this causes the rash to spread.

Appearance
Be weary of any plant with leaves grouped into three pointed leaflets, one in the middle and two pointed to either side. The leaf edges can be smooth or jagged. The plant can grow as a low level plant or as a climbing vine.

To become an absolute expert on identifying poison ivy check out the many photographs at... http://poisonivy.aesir.com/faq.html#Pictures