Dr. Marque says lots of plants can cause that reaction, but it is the urushiol oil in poison ivy, poison oak, and poison sumac that can cause a delayed hypersensitivity and bring people to the doctor looking for relief.
"Usually a rash will show up in one to three days. It lasts for up to three weeks and it usually peaks around a week," said Dr. Marque. "It can cause lots of blistering, scratching, and sometimes those blisters will ooze and people will think that it's contagious, but it's actually not contagious, it's just an inflammatory reaction."
Those poisonous plants are very common in Louisiana and the best way to avoid the discomfort they bring is to know their appearance.
"Poison ivy and poison oak typically form in three leaf clusters from a single branch," said Dr. Marque. "Poison sumac will have five to seven leaves, but that's totally variable."
What the plants do have in common, though, is the oil they release when the leaves are bruised, damaged, or burned.
"The intensity of the rash is dependent on how much oil you get on your skin and how long it's in contact with the skin," said Dr. Marque, "so if you wash it off with warm, soapy water or a mild dishwashing detergent, it's actually very effective at getting it off the skin."
But if you find it is too late, and you have developed the skin rash, Dr. Marque says comfort measures can be taken at home. If it worsens, then you need to see a medical professional.
"You can find some relief with cold compresses, calamine lotion, or oatmeal baths, and that will often just make you feel better," he said. "Topical steroids are often used and occasionally with really severe rashes, especially if they involve the face, we might give them steroid pills or even an injection if it's really bad."
If you plan to burn brush, make sure it does not have these poisonous plants piled in. Inhaling the smoke can cause severe allergic respiratory problems.
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