Overview

Poison ivy rash is an allergic reaction to poison ivy. Poison ivy is very common plant in the U.S. It is similar to two other plants called poison oak and poison sumac. The plants cause allergic dermatitis. This means the body's immune system releases certain chemicals that cause a skin reaction. Most children are allergic to poison ivy.

Causes

Poison ivy has oil called urushiol. This oil causes the allergic skin reaction. The oil is easily wiped from the plants to other objects. These include clothes, toys, and pets. Smoke from a burning plant can also contain the oil.

Risk Factors

Children who live near the plants are at risk for the skin reaction. There are different types of these plants around the country. They are:

  • Poison ivy. This is a ground or climbing vine with leaves grouped in threes in most of the U.S. Another type grows as a shrub in the Western U.S.
  • Poison oak. This is a ground or climbing vine or shrub with leaves grouped in threes. One type grows on the West coast and another type grows mostly in the Southeast.
  • Poison sumac. This is a shrub or small tree with groups of several leaves arranged in pairs. It grows in very wet areas.

Symptoms

Your child may have symptoms within hours or days after coming in contact with poison ivy. The symptoms include:

  • Small bumps where the plant oil touched the skin that quickly turn into blisters
  • Severe itching
  • Redness and swelling
  • Blisters that break, ooze fluid, and crust over. The fluid in the blisters doesn’t spread the rash.

The symptoms of poison ivy rash can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.

Diagnosis

The healthcare provider will ask about your child’s symptoms and health history. He or she will give your child a physical exam.

Treatment

Your child's rash may be treated with over-the counter medicines. You can also help ease your child's symptoms with the following:

  • Bathing your child in water with colloidal oatmeal
  • Applying cool, wet cloths (compresses)
  • Using calamine lotion or corticosteroid cream on the skin
  • Giving your child diphenhydramine liquid by mouth, if itching is making it hard for your child to sleep

Call the healthcare provider if your child:

  • Inhaled smoke from a burning poison ivy plant
  • Has the rash on his or her face
  • Has a severe rash
  • Has a rash on a large part of his or her body

In these cases, your child's healthcare provider may prescribe a prescription medicine such as:

  • Corticosteroid cream
  • Corticosteroid pills or liquid
  • Corticosteroid shot (injection) 

Complications

The rash may become infected with bacteria. 

Prevention

A poison ivy rash can be prevented by avoiding contact with the plant.
Creams containing bentoquatum may be used as a barrier on the skin if contact with the plant is likely. 

The rash can’t spread from one person to another. But oil on your child’s skin can spread to another person who may then get the rash. To help prevent a poison ivy rash:

  • Teach all family members to recognize the plants and stay away from them.
  • Make sure your child wears pants, long sleeves, and shoes and socks when in areas where the plants grow.
  • Wash your child's clothes and shoes right after he or she has been in areas where the plants grow.
  • Make sure your child doesn’t touch a pet that might have been in contact with the plants. Wash your pet after is has contact with the plant.
  • Make sure your child showers or bathes with soap and warm water if he or she has been in an area where the plants grow. To remove all plant oil, help your child wash all areas of his or her body very well. 

When to Call a Healthcare Provider

Call the healthcare provider if your child has:

  • Symptoms not relieved by over-the-counter medicine
  • Rash on his or her face
  • Severe rash
  • Rash that covers a lot of your child's body
  • Signs of a skin infection, such as increased redness, warmth, swelling, or fluid

Key Points

  • Poison ivy, oak, and sumac cause an allergic skin reaction. The reaction is caused by oil from the plant.
  • Avoiding contact with the poison ivy plant is the best prevention.
  • Washing the skin after touching the plant can prevent a rash.
  • The fluid from the blisters doesn’t make poison ivy spread. But oil on the skin can cause a rash if wiped on another person.
  • In most cases, poison ivy rash can be treated at home.
  • A poison ivy rash may be treated with soothing products, calamine lotion, or corticosteroids creams, pills, liquids, or injections.

Next Steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.