What are poison ivy and poison oak?

Poison ivy and poison oak are plants that grow all over the US. They may cause an allergic skin reaction if you touch them.
Poison ivy and poison oak are plants that grow all over the US. They may cause an allergic skin reaction if you touch them.

Poison ivy and poison oak are plants that grow all over the United States. Either plant may cause an allergic reaction on any part of your skin that touches it. 

The plants contain an oily substance called urushiol that is responsible for the allergic reaction.

The best way to protect yourself from getting the reaction is by avoiding these plants and anything that may have touched them.

Poison ivy and poison oak can cause rashes if someone touches them. These may be severe enough to blister and itch for days or weeks. Most cases can be managed at home with household and over-the-counter (OTC) products. Severe cases require medical attention. 

If these plants are burned, inhaling the smoke can cause severe breathing problems. If your shoes, farm tools, pets, or clothes are exposed to the oil, be sure to handle them carefully. 

What is poison ivy?

Poison ivy is the most widely recognized poisonous plant. It grows like a shrub in most parts of North America. It is mostly found in open fields, wooded areas, along the rivers, and on the roadside. 

Poison ivy can also be found in cities. It can grow in parks and vineyards as well. In the summer, a poison ivy plant often has yellow flowers with white berries. In the fall, poison ivy leaves turn yellow and red. 

What is poison oak?

Poison oak also grows like a shrub or vine. It is mostly found in the western part of the U.S. and the Canadian province of British Columbia. 

Poison oak’s leaf arrangement is similar to that of poison ivy with a cluster of three leaflets. The leaves may sometimes look like those of true oak leaves, which is where its name comes from. 

Symptoms of poison ivy and poison oak rash

A rash from one of these poisonous plants usually shows up as red, itchy bumps on your skin. 

An itchy rash often does not start until one to two days after coming into contact with the plant. This rash may develop into painful blisters.  

The rash may last for a few days, or up to two weeks. It is not contagious. The rash does not spread from one person to another. 

However, any oil left on your skin or clothes can be spread to other parts of your body and cause another rash.

Causes of poison ivy and poison oak rash

When someone gets exposed to poison ivy and poison oak, they may experience an allergic reaction. This reaction begins as an itch or small irritation. It then develops into a swollen, red rash on your skin, which becomes itchier. This leaves bumps that can turn into blisters. 

The oil resin in the plants is called urushiol. It is found on the leaves, roots, stems, and flowers of these plants. Almost everyone is allergic to this oil. When your skin touches the oil, an allergic reaction occurs. 

The itchy rash that develops is a type of allergic contact dermatitis. Urushiol remains active even after the plant has died. Airborne contact with urushiol is also possible. Avoid burning the plants to prevent your inhalation of the smoke, which affects your lungs.

Diagnosing reactions to poison ivy and poison oak

Only a licensed healthcare professional can diagnose a severe reaction to poison ivy or oak and prescribe the correct treatment.

Your doctor will look at the rash, assess your symptoms, and ask questions to determine if you could have encountered a poisonous plant. Many allergens and irritants can cause contact dermatitis or an itchy rash, so your doctor will need to rule those out before treating your exposure to poison ivy or oak. 

This is particularly true if you haven’t been outdoors recently.

Treatments for poison ivy or poison oak exposure

There is no cure for the reaction your body has to poison ivy or oak. The best treatment is avoiding it. 

It is important to be able to recognize these plants in order to avoid touching them. If you come in contact with the poison oak or ivy, remove the oil from your skin in the fastest possible way. You can do this by washing with warm water and soap. 

If you are away from water and soap, you can use alcohol-based wet wipes to remove the oils. Wash all of your clothes and shoes that came into contact with the plant to avoid a secondary reaction later on.

If the itching has already begun, visit a doctor, especially if you don’t know its cause. 

The only cure for your allergic reaction is to wait for the rash to improve on its own in two to three weeks. You can treat the symptoms of your reaction during this time by:

  • Taking short, lukewarm baths to ease the itch 
  • Not scratching the area with the rash to avoid further infection
  • Applying cool compresses to the itchy skin 
  • Using over-the-counter (OTC) treatments like calamine lotion, oatmeal baths, or aluminum acetate 
  • Taking oral antihistamine pills to reduce the itching

Consider visiting the doctor if:

  • The rash is not improving after two weeks
  • The rash spreads to sensitive parts of your body, including the genitals
  • You have difficulty breathing.
  • Your face is swollen
  • The rashes begins to cover most of your body

To prevent a poison ivy and poison oak reaction when you are in an area where the plants grow:

  • Teach your family members what the plants look like
  • Wear long pants and sleeves
  • Wash your clothes
  • Avoid touching your pets
  • Wash your hands thoroughly and regularly 


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Medically Reviewed on 2/22/2021

American Academy of Dermatology Association: "POISON IVY, OAK, AND SUMAC: HOW TO TREAT THE RASH."

American Osteopathic College of Dermatology: "POISON IVY DERMATITIS."

Cedars Sinai: "Poison Ivy, Oak, and Sumac Rash."

Cleveland Clinic: "Poison Ivy, Poison Oak and Poison Sumac."


Johns Hopkins Medicine: "Allergens: Poison Ivy / Poison Oak / Poison Sumac."

Poison Control: "Poison Ivy, Poison Oak and Poison Sumac."