
Poison ivy is the most common cause of plant-induced skin reactions (phytodermatitis) in the United States.
- This plant is found in almost every part of the United States except Alaska, Hawaii, and parts of the west coast.
- It generally grows along rivers, lakes, and beaches.
Knowing how it looks like can help prevent the irritating rash poison ivy causes.
Several phrases have evolved to help remember what this plant looks like, thus avoiding coming in contact with it.
- Leaves: “Leaves of three, leave them be.” This saying suggests the way poison ivy leaves are arranged in groups of three or trifoliate patterns. The leaves have pointed tips with coarsely serrated or toothed margins although the leaf margins may appear smooth as well. The leaf surface may be dull or glossy.
- Vine: “Hairy vine, not a friend of mine.” The vine may appear to be having fine hair-like structures on its surface. Poison ivy may grow as a climber straggling vine or a sprawling shrub (western poison ivy).
- Stem: “Longer middle stem, don’t touch them.” The stem or stalk of the middle leaflet is quite long with shorter stalks on the side leaflets.
- Flowers: Flowers appear greenish and grow in loose clusters. They have tiny petals, about 3 mm wide.
- Fruits: The fruits are typically seen in autumn and look like berries although they are quite hard. They appear whitish and contain a single seed.
Identification chart
Here is a breakdown of the differences between poison ivy, poison oak, and poison sumac:
Type | Leaf number | Leaf shape | Leaf color |
---|---|---|---|
Poison ivy | A cluster of three leaves | Pointed leaves | Green, yellow, or red |
Poison oak | A cluster of three leaves | Rounded leaves | Green and may have yellow-white berries |
Poison sumac | Up to 13 leaflets | Pointed leaves | Orange, green, yellow, or red |
What are the symptoms of poison ivy rash?
The symptoms of a poison ivy rash occur due to the resinous substance called urushiol.
If a person comes in contact with the plant or an object (such as shoes) or pet fur contaminated by this resin, they may develop:
- Pruritus or itching
- Skin redness
- Swelling
- Bumps
- Blisters that often weep
- Black spots or streaks
- Red streaks on the skin
The fluid from the blisters does not contain urushiol; thus, it will not cause the spread of the rash to others.
Skin rash due to poison ivy typically appears within 4 hours to 10 days after exposure to the plant. The blisters generally crust over and clear in two to three weeks.
The severity of symptoms and the timing of their appearance depending on individual sensitivity and the amount of contact.
The duration for which the rash may last depends on whether a person was previously exposed to urushiol or not.
- If a person had previously come in contact with poison ivy or other related plants (poison oak or sumac), their rash may clear in 1 to 14 days.
- If, however, you have been exposed for the first time it may take three weeks or more for the rash to go away.
Some people may develop symptoms beyond the skin manifestations, such as coughing, sneezing, and breathing difficulties, as seen in ragweed allergies. Respiratory symptoms (such as coughing and trouble breathing) are particularly seen on inhaling the smoke from a burning poison ivy plant.
What should I do if I come in contact with poison ivy?
If a person comes in contact with poison ivy, they must:
- Immediately wash the skin well with soap and water. Rinse the skin with rubbing alcohol, specialized poison plant washes, degreasing soap (such as dishwashing soap) or detergent, and lots of water.
- Change into clean clothes.
- Scrub the underside of the nails with a brush.
- To get relief from skin irritation and rash:
- Apply ice or cold compresses, calamine lotion, or hydrocortisone cream (according to label instructions)
- Avoid applying any cream or lotion to broken skin or open blisters
- Take oatmeal baths
- To reduce blistering, make a mixture of a tablespoon of white vinegar in a liter of water and compress the areas for 15 minutes two times a day.
- For reducing itching, one may take over-the-counter antihistamines, such as diphenhydramine, following label instructions. Avoid giving antihistamines to children without consulting a doctor.
- Seek immediate medical attention in case of:
- Severe rashes
- Swelling on the face or genitals
- Dizziness or fainting
- Difficulty breathing
- History of a severe allergic reaction in the past
- Fever (temperature above 100°F)
- Pus discharge from the rash

QUESTION
Ringworm is caused by a fungus. See AnswerHealth Solutions From Our Sponsors
DermNet New Zealand. Plant dermatitis. https://dermnetnz.org/topics/plant-dermatitis/
American Academy of Dermatology. Poison ivy, oak, and sumac: what does the rash look like? https://www.aad.org/public/everyday-care/itchy-skin/poison-ivy/what-rash-looks-like
American Museum of Natural History. Tips to Identify Poison Ivy. https://www.amnh.org/learn-teach/curriculum-collections/biodiversity-counts/plant-identification/tips-to-identify-poison-ivy
Top How Can You Tell if It's Poison Ivy Related Articles
Plant and Tree Allergies
Find out more about which plants and trees might be producing pollen that is causing your itchy eyes and a runny nose.What Are the Best Natural Home Remedies for Poison Oak?
What is poison oak? Learn what natural home remedies you can use to relieve your symptoms.What Is the Difference Between Poison Ivy and Poison Oak?
Learn the differences between poison ivy and poison oak and how to treat your exposure to them.How to Get Rid of Poison Ivy Rash
The oil urushiol present in the leaves, roots, and leaves of the poison ivy plant is responsible for the rash that comes after touching it. To get rid of the rash caused by touching poison ivy, you have to also get rid of the oil.Is Poison Ivy Contagious?
Poison ivy produces urushiol, an oily chemical that causes an itchy, painful reddish rash in people who come in contact with the plant. The rash lasts for one to three weeks. People should seek medical care for poison ivy exposure if the resulting rash covers a large portion of the body, if the rash develops on the genitalia or face, or if there is swelling around the eyes or of the throat.Poison Ivy Picture
Poison ivy has characteristic shiny, red, three-leaf configuration. See a picture of Poison Ivy and learn more about the health topic.Poison Ivy, Oak, and Sumac
Poison ivy, oak, and sumac contain a substance called urushiol, which causes a rash on people who come in contact with them. Symptoms and signs include a red, swollen, itchy, blistering, bumpy rash. Treatment involves rinsing the exposed area with water, taking antihistamines and over-the-counter pain medications, using topical treatments such as calamine lotion, and applying cool compresses.Poison Ivy, Oak, and Sumac: Plants and Rashes
Poison ivy, poison oak, and poison sumac are plants that can cause a rash if you come in contact with the urushiol oil found in them. Even when dried-up, their leaves and stems can cause a rash.Summer Skin Quiz
When it comes to summer, there plenty of hazards under the sun! Take the Summer Skin Hazards Quiz and clue in on the dangers to your summer skin!