Poison ivy is one of the most frequent causes of skin rash among children and adults who spend time outdoors. The plant can be found throughout the United States, except in the Southwest, Alaska and Hawaii. It has three shiny green leaves and a red stem. Poison ivy typically grows in the form of a vine, often along riverbanks.

The rash is caused by skin contact with the oils (resin) of the poison ivy plant. Smoke from burning this plant can cause the same reaction. The oils usually enter the skin rapidly. It is rarely spread from person to person.

The rash does not spread by the fluid from the blisters. Therefore, once a person has washed the oil completely off the skin, the rash is usually not contagious.

Keep in mind that the plant oils may remain for a long time on contaminated clothing, pets, tools, shoes and other surfaces. These contaminated items can cause rashes in the future if they are not properly cleaned.

Symptoms of poison ivy include:

• Extreme itching
• Red, streaky, patchy rash where the plant touched the skin
• Red bumps, which may form large, weeping blisters

The worst symptoms are often seen during four to seven days after exposure. The rash may last up to three weeks.

Call 911 or go to an emergency room if:

• Someone is suffering a severe allergic reaction, such as swelling or difficulty breathing, or has had a severe reaction in the past.
• Someone has been exposed to the smoke of a burning plant.

Call your provider if:

• Itching is severe and cannot be controlled.
• The rash affects your face, lips, eyes or genitals.
• The rash shows signs of infection, such as pus, yellow fluid leaking from blisters, odor or increased tenderness.

Preventing Poison Ivy

• Wear long sleeves, long pants and socks when walking in areas where these plants may grow.
• Skin products such as Ivy Block lotion can be applied beforehand to reduce the risk of a rash.
• Learn to identify poison ivy, oak and sumac. Teach your children to identify them as soon as they are able.
• Remove these plants if they grow near your home (but never burn them).
• Be aware of resins carried by pets.
• Wash as soon as possible after a suspected exposure.