Poison ivy, poison oak, and poison sumac are all plants that contain an irritating, oily sap called urushiol – which can trigger an allergic reaction when it comes into direct contact with skin. You can also be exposed to urushiol by touching objects, like gardening tools and camping equipment, that have come into contact with one of the poison plants. Common signs and symptoms of an allergic reaction include:

• Swelling
• Itching
• Redness
• Blisters

A rash from contact with a poison plant’s urushiol often appears in a line across the skin but can spread anywhere on the body via clothing and scratching if the urushiol is not removed. Reactions usually develop within a couple days of exposure and may last up to three weeks.

How to Avoid Poison Plant Reactions

Poison ivy, poison oak, and poison sumac are three of the most common causes of allergic contact dermatitis in North America. But there are steps you can take to prevent reactions:

• Learn to identify poison ivy, poison oak, and poison sumac, and avoid contact with them. The saying, “Leaves of three, let them be!” is helpful for identifying poison ivy and oak. Poison sumac usually has 7-13 leaves arranged in clusters.
• When walking in the woods or working in places where these plants may grow, cover your skin as much as possible by wearing long-sleeves, pants, socks, and shoes.
• Wear heavy-duty vinyl gloves when doing yard work or gardening as urushiol can seep through latex or rubber gloves.
• If you come into contact with a poison plant, wash all clothes and shoes in soap and water. Also, wash the exposed area of the skin with soap and water for at least 10 minutes after the plant or the oil is touched.
• Apply over-the-counter (OTC) skin products that are intended to act as a barrier between your skin and urushiol.

How to Treat Poison Plant Reactions

Symptoms such as rashes, blisters, and itching normally disappear in several weeks without any treatment. You can find some relief by:

• Soak the rash in cool water or apply a cold compress.
• If the rash is mild, apply calamine lotion to dry the oozing – avoid ointments that contain anesthetics or antihistamines as they can cause allergic reactions themselves.
• Apply an over-the-counter (OTC) hydrocortisone cream or ointment on rashes that aren’t scratched open or raw.
• Trim your fingernails to prevent the rash from spreading, in case there is any trace urushiol left under your nails.

While mild cases can be treated at home, talk with your doctor or other healthcare professional if you are especially uncomfortable, if the rash is severe and/or isn’t going away, if the rash is on your face or groin area, or if you notice signs of infection such as fever, redness, and/or swelling beyond the lesions.