Family Health Guide

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Rashes: Poison Ivy


You probably remember the rhyme from when you were a kid: "Leaves of three, let them be." The rash caused by the poison ivy plant is red, raised, and can have small bumps and blisters. It usually appears a day or two after exposure and may even show up in streaky lines from the way your child brushed against the plant. A case of poison ivy can be almost unbearably itchy. Poison oak (which also has three leaves) and poison sumac plants also produce the same reaction. 


Kids who develop this rash are experiencing an allergic reaction to the urushiol oil that’s in poison ivy, poison oak, and poison sumac. About 85 percent of the population is allergic to urushiol, and will develop the rash when exposed. (Never had it? Don't get cocky -- the sensitivity can develop at any time.) 


Examining a child’s skin and learning about his recent encounters with nature will help a doctor diagnose a poison ivy rash. 


Teach your child to recognize dangerous plants and avoid them. Poison ivy has three glossy leaflets with toothed or smooth edges. Poison oak has a trio of dark green, fuzzy leaves that are lobe-shaped. Poison sumac has seven to 12 smooth edged leaflets per plant. Have kids wear long sleeves, pants, and socks or tall boots if they’re going for a walk in the woods. If you suspect your child has accidentally brushed against one of these plants, wash his skin and clothes immediately (the urushiol oil can remain in the clothes indefinitely and reinfect him if they're not washed). You don’t need to worry about keeping your child away from someone with a poison ivy rash, however; it’s not contagious. 


Poison ivy rash usually goes away on its own in one to three weeks. Meanwhile, over-the-counter hydrocortisone cream (1%), calamine lotion, and over-the-counter Benadryl (diphenhydramine) can help control the itching -- important because if a child has germy fingernails and scratches an open poison ivy wound, it can develop a bacterial infection that requires antibiotics. If the rash is widespread or affects a sensitive area such as the eyes, mouth, or genitals, see a doctor who may prescribe an oral corticosteroid such as prednisone.  

Complementary/Alternative Treatments

Dab the rash with white vinegar several times a day, apply cool compresses regularly, and have your child soak in an oatmeal bath.