Poison Ivy / Contact Dermatitis

Summertime means outside playtime. One of the most common causes for a visit with the pediatrician is Poison Ivy or Contact Dermatitis. There are many different varieties of plants that when coming in contact with the skin, cause rashes that itch. Some plants that are included in the category include: Poison Ivy, Poison Oak, and Poison Sumac.

What does a Poison Ivy rash look like?

Classic Poison Ivy is a red, raised, and itchy. It is often found in patches that are oriented in a linear fashion. This is caused by the skin brushing against a leaf or stem. The rash also blanches. Blanching means that when pressure is applied to the rash, the redness will disappear, then return when the pressure is released. There can also be some swelling caused by local release of inflammatory mediators.

How does Poison Ivy spread?

The irritant that is found on the plant can be spread from location to location by touching with bare skin or even on clothing. The irritant can also be spread via the airborne route in smoke if the plant is burned. Once clothes and the skin has been washed, new patches do not arise from direct contact. New areas of redness or swelling can occur even days later as the body continues to produce an inflammatory reaction.

How long does it last?

Duration of symptoms can vary. It can last for a few days or even up to two weeks.

What is the best way to treat Poison Ivy?

In most cases, the condition is self limited. Treatment is targeted at symptoms. Many things can be helpful, but antihistamines taken by mouth are preferred. An example would be over-the-counter Benedryl (diphenhydramine). An approximate dose is 1 teaspoon per 22 pounds given every 6 hours as needed. Each teaspoon contains 12.5 mg of diphenhydramine. The adult dose is 25-50 mg every 6 hours as needed and should not be exceeded regardless of the child's weight. The most common side effect of this medication is somnolence which is dose related (increased dose leads to increased somnolence). Some children may get paradoxically hyper. Other topical agents can be used such as calamine or other over-the-counter anti-itch meds. Sometimes an oatmeal bath can be soothing.

When should medical attention be sought?

In cases of severe reaction, children should be evaluated by the pediatrician. The symptoms included in this category include: respiratory complaints such as difficulty breathing or shortness of breath, severe swelling, or symptoms uncontrolled by over-the-counter medications. As with any medical condition, if the parent is concerned, the child should be evaluated.

What more can the doctor do?

There are prescription medications that can be helpful in severe cases.

JDMD 7/9/01