If you spend time outdoors, chances are you have been bothered by poison ivy, poison oak or poison sumac at some point. Most people are sensitive to the plants' oily sap. The sap is in the root, stems, leaves and fruit of these plants. If it gets on your skin, it causes a blistering skin rash. The rash can range from mild to severe, depending on how much sap gets on your skin and how sensitive you are to it. Problems can also happen if the plants are burned. Airborne sap-coated soot can get into the eyes, nose, throat and respiratory system.

The best way to avoid the rash is to learn what the plants look like and stay away from them. If you come into contact with the plants, wash your skin and clothing right away. If you develop a rash, ask your pharmacist about over-the-counter medicines. For severe rashes, see your doctor.

The old saying “Leaves of three, Let it be!” is a helpful reminder for identifying poison ivy and oak, but not poison sumac which usually has clusters of 7-13 leaves. Even poison ivy and poison oak may have more than three leaves and their form may vary greatly depending upon the exact species encountered, the local environment, and the season. Being able to identify local varieties of these poisonous plants throughout the seasons and differentiating them from common nonpoisonous look-a-likes are the major keys to avoiding exposure.

Poison Ivy

• Eastern poison ivy is typically a hairy, ropelike vine with three shiny green (or red in the fall) leaves budding from one small stem
• Western poison ivy is typically a low shrub with three leaves that does not form a climbing vine
• May have yellow or green flowers and white to green-yellow or amber berries

Poison Oak

• Typically a shrub with leaves of three, similar to poison ivy
• Pacific poison oak may be vine-like
• May have yellow or green flowers and clusters of green-yellow or white berries

Poison Sumac

• Woody shrub that has stems that contain 7-13 leaves arranged in pairs
• May have glossy, pale yellow, or cream-colored berries

Poison ivy, poison oak, and poison sumac release an oil, urushiol, when the leaf or other plant parts are bruised, damaged, or burned. When the oil gets on the skin an allergic reaction, referred to as contact dermatitis, occurs in most exposed people as an itchy red rash with bumps or blisters. When exposed to 50 micrograms of urushiol, an amount that is less than one grain of table salt, 80 to 90 percent of adults will develop a rash. The rash, depending upon where it occurs and how broadly it is spread, may significantly impede or prevent a person from working. Burning these poisonous plants can be very dangerous because the allergens can be inhaled, causing lung irritation.

Workers may become exposed to urushiol through:

• Direct contact with the plant
• Indirect contact, such as touching tools, livestock, or clothing that have urushiol on them
• Inhalation of particles containing urushiol from burning plants

Symptoms

Signs or symptoms associated with dermal contact with poisonous plants may include:

• Red rash within a few days of contact
• Possible bumps, patches, streaking, or weeping blisters (blister fluids are not contagious)
• Swelling
• Itching

First Aid

Workers who have come in contact with poisonous plants should:

• Immediately rinse skin with rubbing alcohol, specialized poison plant washes, degreasing soap (such as dishwashing soap) or detergent, and lots of water.
  • Rinse frequently so that wash solutions do not dry on the skin and further spread the urushiol.
• Scrub under nails with a brush.
• Apply wet compresses, calamine lotion, or hydrocortisone cream to the skin to reduce itching and blistering.
  • Follow the directions on any creams and lotions. Do not apply to broken skin, such as open blisters.
  • Oatmeal baths may relieve itching.
• An antihistamine such as diphenhydramine (Benadryl) can be taken to help relieve itching.
  • Follow directions on the package.
  • Drowsiness may occur.
  • If children come in contact with work clothing contaminated with urushiol, a pediatrician should be contacted to determine appropriate dosage.
• In severe cases or if the rash is on the face or genitals, seek professional medical attention.
• Call 911 or go to a hospital emergency room if the worker is suffering a severe allergic reaction, such as swelling or difficulty breathing, or has had a severe reaction in the past.

First comes the itching, then a red rash, and then blisters. These symptoms of poison ivy, poison oak, and poison sumac can emerge any time from a few hours to several days after exposure to the plant oil found in the sap of these poisonous plants. The culprit: the urushiol oil. Here are some tips to avoid it.

Recognizing Poison Ivy, Poison Oak, and Poison Sumac

• Poison Ivy: Found throughout the United States except Alaska, Hawaii, and parts of the West Coast. Can grow as a vine or small shrub trailing along the ground or climbing on low plants, trees and poles. Each leaf has three glossy leaflets, with smooth or toothed edges. Leaves are reddish in spring, green in summer, and yellow, orange, or red in fall. May have greenish-white flowers and whitish-yellow berries.
• Poison Oak: Grows as a low shrub in the Eastern and Southern United States, and in tall clumps or long vines on the Pacific Coast. Fuzzy green leaves in clusters of three are lobed or deeply toothed with rounded tips. May have yellow-white berries.
• Poison Sumac: Grows as a tall shrub or small tree in bogs or swamps in the Northeast, Midwest, and parts of the Southeast. Each leaf has clusters of seven to 13 smooth-edged leaflets. Leaves are orange in spring, green in summer, and yellow, orange, or red in fall. May have yellow-greenish flowers and whitish-green fruits hang in loose clusters.

Poison Plant Rashes Aren’t Contagious

Poison ivy and other poison plant rashes can’t be spread from person to person. But it is possible to pick up the rash from plant oil that may have stuck to clothing, pets, garden tools, and other items that have come in contact with these plants. The plant oil lingers (sometimes for years) on virtually any surface until it’s washed off with water or rubbing alcohol.

The rash will occur only where the plant oil has touched the skin, so a person with poison ivy can’t spread it on the body by scratching. It may seem like the rash is spreading if it appears over time instead of all at once. But this is either because the plant oil is absorbed at different rates on different parts of the body or because of repeated exposure to contaminated objects or plant oil trapped under the fingernails. Even if blisters break, the fluid in the blisters is not plant oil and cannot further spread the rash.

Tips for Prevention

• Learn what poison ivy, oak, and sumac plants look like so you can avoid them.
• Wash your garden tools and gloves regularly. If you think you may be working around poison ivy, wear long sleeves, long pants tucked into boots, and impermeable gloves.
• Wash your pet if it may have brushed up against poison ivy, oak, or sumac. Use pet shampoo and water while wearing rubber gloves, such as dishwashing gloves. Most pets are not sensitive to poison ivy, but the oil can stick to their fur and cause a reaction in someone who pets them.
• Wash your skin in soap and cool water as soon as possible if you come in contact with a poisonous plant. The sooner you cleanse the skin, the greater the chance that you can remove the plant oil or help prevent further spread.

Tips for Treatment

Don’t scratch the blisters. Bacteria from under your fingernails can get into them and cause an infection. The rash, blisters, and itch normally disappear in several weeks without any treatment.

You can relieve the itch by:

• Using wet compresses or soaking in cool water.
• Applying over-the-counter (OTC) topical corticosteroid preparations or taking prescription oral corticosteroids.
• Applying topical OTC skin protectants, such as zinc acetate, zinc carbonate, zinc oxide, and calamine dry the oozing and weeping of poison ivy, poison oak, and poison sumac. Protectants such as baking soda or colloidal oatmeal relieve minor irritation and itching. Aluminum acetate is an astringent that relieves rash.

See a doctor if:

• You have a temperature over 100 degrees Fahrenheit.
• There is pus, soft yellow scabs, or tenderness on the rash.
• The itching gets worse or keeps you awake at night.
• The rash spreads to your eyes, mouth, genital area, or covers more than one-fourth of your skin area.
• The rash is not improving within a few weeks.
• The rash is widespread and severe.
• You have difficulty breathing.

Have a scratch-free summer!