Flowers are blooming, and vegetables are beginning to grow. Gardening is a hobby that offers beauty and a harvest of nutritious produce. But it also presents a danger. You could come into contact with noxious plants such as poison oak, poison ivy, or poison sumac. 

What happens when you touch poisonous plants?

Brushing against the leaves of poisonous plants triggers an allergic reaction, also called contact dermatitis or Rhus dermatitis. The unlucky person develops a hypersensitivity reaction to urushiol oil found in the sap of the plant. The reaction can start quickly, within a couple of minutes of exposure. As the oil disperses on the skin, the rash spreads.

Some people do not react to urushiol; it all depends on whether the person is allergic. Between 75 and 85 percent of American adults have a Rhus allergy. Fifty percent will have a consistent reaction every time they have contact; between 25 and 35 percent will only react with higher doses of the oil.

Unfortunately, poison ivy, poison oak, and poison sumac are very common plants that are found throughout the United States, with the exception of Alaska, Hawaii, and the desert Southwest.

Unexpected dangers of urushiol

Most of us imagine that we only encounter urushiol by touching poisonous plants. However, there are surprising ways that we can come into contact with urushiol and experience a reaction. 

  • Burning the plants can lead to inhaling the urushiol as a vapor. This can cause a serious allergic reaction affecting the nasal passages, throat, and lungs.
  • Your pets can transfer the urushiol to you. Be mindful that you can also pick up the irritating oil by patting a dog or cat that has come in contact with poison ivy, oak, or sumac.
  • The skin of mangos and the shells of cashews and pistachios also contain urushiol oil. Mangos should be washed with warm water and carefully peeled before eating. The risk of a reaction from nuts is lower, as the oil in the shells is neutralized when the nuts are heated during processing.  

How to avoid poisonous plants

With a little preparation, encountering poisonous plants in your garden doesn't have to end badly. Wearing gloves and protective clothing that covers your skin when working in the yard will keep the oil from contacting your skin.

What to do if you touch poison ivy, poison oak, or poison sumac

If you know that you have come in contact with the oil, wash immediately or at least within 10 minutes with soap and water. Because the oil repels water, rinsing isn’t enough to prevent a rash. Be sure to also clean all contaminated tools, clothing, shoes, and linens.

How to treat a rash from poisonous plants

While a reaction to poisonous plants is no fun, they can mostly be treated at home with over the counter medications if needed. The itching can last from minutes to hours to days, depending on the strength of your reaction to urushiol. Typically, the rash develops over the course of one to two days and resolves within 10 to 14 days.

  • Soothe the rash and blisters using a cool compress for 15 to 20 minutes each hour.
  • Calamine lotion and over-the-counter oral antihistamines (not topical antihistamines) help with the itching and swelling.
  • Don’t scratch; leave blisters alone.
  • Lukewarm colloidal oatmeal baths may provide some comfort. You can also try adding a cup of baking soda to the bath as you are running the water.

When to see a doctor for a poison ivy reaction

If the reaction is severe, widespread, or near your eyes, see your doctor, who may prescribe topical and/or oral steroids to relieve symptoms. If you are having difficulty breathing or swallowing, go to the emergency department or call 9-1-1.

So, remember these words of warning: “Leaves of three, let them be!” Learn how to identify poisonous plants.

For more tips to help you and your family live healthy lives, visit the Lifespan Living health and wellness blog.

Coastal Medical Primary Care Team

Coastal Medical Primary Care Team provides crucial services for your long-term health and well-being at several locations in Rhode Island.