The Dangers in Gardens – Poisonous Plants
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, ivy, or sumac.
Brushing against the leaves of these 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 in 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, oak, and sumac are very common plants that are found throughout the United States, with the exception of Alaska, Hawaii, and the desert Southwest.
Things to know
- Be sure to wear gloves and protective clothing that covers your skin when working in the yard.
- Inhaling smoke from burning the plants can cause a serious allergic reaction affecting the nasal passages, throat, and lungs.
- An unexpected source of urushiol is the skin of mangos. The fruit should be washed with warm water and carefully peeled before eating.
- The oil is also found in the shells of cashews and pistachios but is neutralized when the nuts are heated during processing.
- 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.
- 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.
Treating the rash
- 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 and leave blisters alone.
- Lukewarm colloidal oatmeal baths may provide some comfort or try adding a cup of baking soda to the bath as you are running the water.
- 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.
- 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.
So, remember these words of warning: “Leaves of three, let them be!” Learn how to identify poisonous plants here.
About the Author:
Sami Assad, MD
Dr. Sami Assad is a physician with Lifespan Physician Group Primary Care in Newport.
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