How to Recognize Poison Ivy

Your child was playing outside (yes!) but then an hour later, is scratching their arms or legs (no!) Nature is abuzz with irritants that can lead to itchy rashes, including insect bites and hives. But often, the culprit is poison ivy.

Every parent should know what poison ivy looks like—the plant and the rash. Poison ivy (Toxicodendron radicans or Toxicodendron rydbergii) and its cousins, poison oak and poison sumac, grow widely throughout North America. While not truly poisonous, they all cause a painfully itchy rash upon contact due to an oil called urushiol on their leaves, stems, and roots.

Here, learn how to recognize poison ivy plants (and lookalikes), identify the telltale rash it causes, and what treatments work to soothe the itch.

What Poison Ivy Looks Like

Although poison ivy isn't the only plant with leaves that grow in clusters of three, the adage "leaves of three, leave them be" is useful for spotting poison ivy and helping kids remember what to steer clear of. Here are this troublesome plant's distinguishing features:

• Leaves: Both eastern and western poison ivy have green, 2- to 4-inch-long leaves that grow in groups of three. Young plants may display reddish, droopy leaves. Mature poison ivy leaves are smooth, can be glossy or dull, and turn bright red and yellow in the fall. Leaf edges can be lobed or smooth.
• Flowers and berries: In the springtime, small yellow flowers bloom close to the stem or vine of the plant. Later in the summer, the blossoms are replaced by light green, gray, or white berries.
• Roots and stems: Poison ivy stems are thornless. They will root where they make contact with the ground, which makes the plant difficult to kill because pieces of the stem and roots can grow into new plants.

Where Poison Ivy Grows

Poison ivy grows throughout the United States, except in Alaska, Hawaii, and some rainforest and desert regions of the West. It can be found in forests and wetlands, on beaches, along streams, and even in urban parks and your own backyard.

The two types of poison ivy do have slightly different geographic ranges:

• Eastern poison ivy: Leaves grow on a fuzzy vine along the ground or up tree trunks. This variety grows prolifically in the eastern regions of North America, though it can be found as far west as Arizona.
• Western poison ivy: Look for a low-growing shrub, typically under 3 feet tall. Name aside, these plants grow all over the US, from the Northeast to the Great Plains to the Western deserts.

What Poison Oak and Poison Sumac Look Like

Poison oak and sumac are in the same genus as poison ivy (Toxicodendron) and contain the same skin irritant, urushiol. While the terms are often used interchangeably, there are differences in the appearance of poison ivy, oak, and sumac.

• Poison oak: This plant has three leaflets like poison ivy, but its leaves have rounded edges (similar to oak leaves). Their undersides are fuzzy and are generally lighter green than poison ivy. The plant is also more shrub-like than poison ivy. Poison oak grows mostly west of the Rocky Mountains.
• Poison sumac: Look for seven to 13 smooth leaflets arranged in pairs along a slender stem. It looks like a shrub or small tree that can reach 25 feet. In the fall, poison sumac has red stems with orange-red leaves. This plant is most common in the southeastern United States, although it can also be found in the Great Lakes region and Northeast.
  

What Poison Ivy Rash Looks Like

A poison ivy rash develops anywhere from one to seven days after exposure to the plant. How quickly the rash appears and develops depends on how much urushiol is present as well as a person's skin thickness and sensitivity.

A poison ivy rash has the following features:

• Itching (can be intense)
• Painful blisters or vesicles filled with fluid
• Red bumps that appear in straight lines or streaks
• Swelling

The symptoms of poison ivy rash can worsen over the days following contact. The rash tends to take longer to appear on areas with thicker skin, such as elbows and knees.

How To Treat Poison Ivy Rash

There is no cure for poison ivy rash other than time. Poison ivy rash generally takes about seven to 10 days to resolve.

However, some home remedies may help relieve the symptoms and encourage healing. The American Academy of Dermatology (AAD) recommends trying:

• Topical cortisone: Topical steroid creams and gels can reduce inflammation and irritation.
• Anti-itch creams: Creams and lotions made with antihistamines or calamine can help soothe the itch.
• Cool compresses: Apply cool, wet compresses to the itchy areas for 15 to 30 minutes several times a day.
• Cool oatmeal baths: Cool or lukewarm colloidal oatmeal baths can help relieve the itchiness while the rash heals.

Although it can be difficult (especially for children), tell your kids to try their best not to scratch the affected areas, as this can cause infection. However, it's a myth that scratching or opening up blisters can spread the rash to different body parts or other people.

How To Protect Against Poison Ivy Rash

Luckily, there are ways to avoid poison ivy—the plant and the nasty rash it causes. Follow these tips to stay out of poison ivy's way and stop the rash in its tracks if you encounter it.

Avoid contact with poison ivy

Be on the lookout for poison plants all year long. The urushiol in poison ivy, oak, and sumac remains in the roots, stems, and leaves even when the plant is dead, so you can still get a poison ivy rash in the winter.

Because the slightest contact with the plant can cause a rash, protect yourself and your family by taking these precautions when you are outdoors in places where poison ivy thrives:

• Wear the right clothing: Think about long pants, a long-sleeved shirt, and boots with tall socks.
• Wear gloves: Make sure they are long enough to cover the ends of your shirt sleeves.
• Choose the correct footwear: Boots are best if you're hiking because they will protect your ankles and feet. Always wear closed-toe shoes.
• Avoid areas where poison ivy is common: Stick to the middle of paths and trails, avoiding shortcuts through the woods.
  
• Use protective lotion: Over-the-counter bentoquatam lotion (like Ivy Block) shields skin from absorbing the plant's oils. Ask a health care provider before using on children under the age of 6.

Stop a poison ivy rash after contact

Think you or your child has touched poison ivy? With these steps, you may be able to keep the rash from appearing or spreading:

• Immediately wash the skin. You want to remove as much urushiol as possible right away. Soap and water may work, but an over-the-counter poison ivy skin cleanser (like Technu) is more effective.
• Change your clothes: Urushiol oil may be on your clothes, so put them in the washing machine as soon as you get home.
• Hose down gardening or other equipment: If rakes, shovels, or boots come in contact with the plant, they can transfer the irritating oils to your skin later.

Even if you can identify poison ivy, poison oak, and sumac, it's possible to bump into it accidentally or get a rash through contact with the oils on pets or clothes. If you start developing a rash, administer home remedies or over-the-counter treatments as soon as possible to relieve your symptoms. You can also call your health care provider if you have any concerns.