Poison Ivy:

Poison Ivy (and its relatives, Poison Oak and Poison Sumac) are very troublesome summertime problems. Of these three, poison ivy is by far the most prevalent in the Kansas City area. These plants produce an oil that is very irritating to anything that touches them. It is not an allergic phenomenon. That is, you do not need to be sensitized to poison ivy before you will react to it. That being said, there do seem to be certain people who are more sensitive than others are.

[Picture from Poison Ivy: How to identify and Control. Copyright 1996 by the Conservation Commission of the State of Missouri. Reproduced with permission. D]

The reaction is twofold. There is an initial, quick reaction that produces redness, swelling, and itching in the first few minutes to hours following contact. A second reaction follows a longer time line. This can produce the symptoms of contact up to several days following exposure. This delayed reaction is the reason that the poison ivy seems to spread over the body. 

If you are exposed to poison ivy, the first measure is to wash the area quickly. Soap and water deactivate the Rhus antigen (the active portion of the oil). However, the oil also is absorbed into the skin very quickly, so washing must be immediate. Cool compresses may be used at home to ease the itching and swelling. Benadryl may help relieve some of the symptoms. The expected duration of the rash is two weeks.

For very bad cases, topical steroids may be used. If the swelling involves the face, contact your doctor immediately. Depending on how bad the reaction is, you might even need oral steroids. This is used for only the worst cases.

You should also remember that the oils linger on articles of clothing and camping equipment. Therefore, if you think you have come in contact with poison ivy, you should wash all clothing and any equipment that might have been contaminated. This also applies to pets. The oil can cling to fur and be transferred to humans days or even weeks after the pet is exposed.

The only effective prevention is avoidance of the offending plants. In other words, make certain you know what poison ivy looks like, and keep the kids away from it. It is often found in wooded areas, in thick bushes and other areas. However, it can be found in urban and suburban areas as well.

There are certain characteristics to look for. Poison ivy tends to have three leaflets grouped together, with the central leaflet on on a thin stalk. Close observation of the above picture will also reveal the outer pairs of leaflets have a small protuberance on the outer edge. They look somewhat like mittens, held palm-up. This is not always present, so do not rely on it for identification. Poison ivy can grow as a vine on walls, fence posts, on a tree, or by itself like a very small shrub.

A common mimic is Virginia Creeper, which is a vine, but it tends to have variable leaflet pattern, with up to five in a cluster. There is no central stalk in the clusters. However, it is easy to miss poison ivy, even if you are looking for it. The best caution is to remember what we teach Cub Scouts:

"Leaflets three, let it be."

For further information, an excellent resource is the Conservation Commission of the State of Missouri.

Call your doctor immediately if:

• The swelling involves the face.
• Your child has difficulty breathing.

Call your doctor during normal office hours if:

• The rash becomes infected (pus or soft yellow scabs).
• The rash lasts longer than two weeks.
• You have any other questions.