Poison sumac (Toxicodendron vernix) is a tree commonly found in the eastern and southern parts of the United States. Contact with any part of this plant can cause an allergic reaction to urushiol, the oil found in its leaves. Approximately 85 percent of the population is allergic to urushiol. This allergic reaction generally takes the form of a rash that can last for up to three weeks and will generally go away on its own, but persistent cases may require medical intervention. This plant is considerably more toxic than its cousins, poison ivy and poison oak.
Poison sumac trees and shrubs are distinguished by their reddish stems, and a pattern of seven to 13 leaves on each stem arranged in pairs, with a single leaf the end. The leaves have a velvety texture and start out a bright orange color in early spring, turn glossy dark green in the late spring, and morph to a red-orange in the fall. The tree rarely grows taller than 30 feet and produces small white clusters of berries in the late spring and early summer.
Poison sumac bushes are found in wetlands and marshy areas, as well as pine and hardwood forests of the eastern and southern quadrants of the United States. The plant is especially prevalent around the Mississippi River, the swamplands of Georgia, Florida, and the Carolinas.
Poison sumac rash develops when a person comes into contact with the urushiol oil released by the plant's leaves and has an allergic reaction. All parts of the plant are toxic and remain so even when the plant dies. Signs of this rash can appear between 8 and 48 hours after exposure and last for weeks.
The symptoms of this type of rash include itchiness, a burning sensation on the skin, watery blisters, redness, and swelling. Symptoms generally peak within one week but can last for up to three. They are often uncomfortable and can cause more serious issues in extreme cases.
The first thing to do if you suspect you have been exposed is to wash your hands thoroughly with warm, soapy water and remove and wash the clothes you were wearing. Urushiol can cause an allergic reaction very quickly, so it's important not to wait. Even brushing against the leaves can potentially cause a rash.
Medical attention isn't always required when you've had contact with poison sumac. However, if the rash is widespread or if it is on your face, seek medical attention. In addition, head to the emergency room if you experience nausea, shortness of breath, or swelling in conjunction with the rash.
The rash seldom leads to complications. However, if you itch the blisters, they may open and bleed, which can lead to infections from bacteria and other germs that enter the wounds. Signs of an infection include redness, pain and oozing from the blisters. Treatment for such infections generally involves antibiotics.
People living in areas where it is prevalent should know how to identify the plant and, if handling is necessary, do so with extreme care and protective clothing, including heavy gloves and boots. Burning the leaves can cause the toxic oil in this plant to be inhaled, which can lead to potentially fatal lung infections.
The rash is not contagious, and you can't get it from coming in contact with rash blisters on another person. The only way you can get poison sumac rash is to come in contact with the leaves of the sumac bush, or with an item that still has the urushiol oil on it.
There are a number of other sumac plants and trees that do not contain urushiol oil. Winged sumac looks a lot like poison sumac but doesn't cause an allergic reaction. In addition, staghorn sumac, the most common type of sumac plant, is also non-allergic.
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