About Poison Oak, Ivy and Sumac

The pithy advice "Leaves of three, let it be" has long been around as a warning against touching those poisonous plants that can leave a person itching like mad. Poison oak, ivy and sumac are the three most common and likely culprits when it comes to leaving a wooded area with welts and scratches on your arms or legs.

Significance

• Poison oak, ivy and sumac are one of the biggest causes of what is known as contact dermatitus in North America. All three of these plants are members of the same plant genus called toxicodendron. The part of the ivy, oak and sumac that create all the misery is an oil called urushiol. Urushiol is antigen is one of the most intense sensitizers in the plant world. It is estimated that up to 85 percent of those who have the slightest contact with a plant containing urushiol will develop contact dermatitis.

Identification

• Despite the admonition to stay away from leaves of three, many people suffer the miseries associated with coming into contact with poison oak, ivy and sumac because they are not so easy to recognize. These plants can grow as shrubs or as long, woody vines. The leaves might be as shiny as an plastic leaf or dull. The length of the poisonous leaves can range from 1 inch to over 5 inches. The edges of the leaves can be smooth or saw-toothed, and although usually green, they can change to yellow or pink.

Effects

• The reaction to exposure to poison oak, ivy and sumac can take between 12 and 18 hours, although the rash that is the most obvious sign may not show up for another few days. During that 12- to 18-hour period the skin will become red with small bumps and possibly blistering developing. When the rash does develop it can often show up in lines that correspond to the exact place where the hand made contact with the leaf.

Features

• The rash that develops from exposure to poison oak, ivy and sumac is differentiated from similar appearing rashes by the overwhelming itchiness. The blisters that developed early may begin seeping liquid until a yellow crust forms over them. The crust will usually fall off and when it does the skin beneath becomes often excruciatingly sore. The rash from poison ivy is particularly sensitive to bacterial infection, especially if there is too much scratching.

Prevention/Solution

• Washing the affected skin area within 15 minutes of contact with simple water and mild soap can result in avoiding the effects of the rash altogether. If not water is available, rubbing alcohol cam accomplish the same thing. If no rubbing alcohol is available, any alcoholic beverage will do in a pinch. Hydrocortisone cream can alleviate many of the symptoms as long as it is applied soon enough after exposure, before any swelling or blistering takes place.

Warning

• Until you are able to wash the skin, avoid touching it. The oils of the poisonous plants are probably still on your fingers, and applying those fingers to any other part of your body is going to result in spreading the rash. Also avoid any use of antihistamine creams or benzocaine because of the potential for increasing the sensitivity when the affected skin is touched or comes into contact with an object.

Misconceptions

• The most dangerous misconception related to poisonous plants like oak, ivy and sumac is that if you aren't affected adversely the first time you come into contact with it, then you must have some sort of immunity. While it is entirely possible for a person to come into contact with these plants even two or three times without being affected, the person will suffer from contract dermatitis the next time he comes into contact with these plants.