Q. My son is going camping next month. Every year, he gets poison ivy. Do you have any pointers for preventing poison ivy? What type of over-the-counter medications should he take with him on the trip, in case he gets it again? How do we know if he should seek medical care?
Poison ivy contains an oil called urushiol. As many as 85 percent of people are allergic to urushiol and will develop a rash after contact with poison ivy. You can also develop the rash from indirect contact with poison ivy - for example, if the plant resin is present on a pet, clothing or camping equipment. The rash typically will appear about 12 hours after exposure and may worsen or progress over the next several days.
To prevent poison ivy, it is important to be able to identify and avoid the plant. Remember the phrase, "Leaves of three, beware of me." If poison ivy cannot be avoided, then wear long pants, long sleeves, gloves and consider applying a barrier cream such as bentoquatam (one brand name: Ivy Block) .
If your son comes into contact with poison ivy, he should wash the area with cold water (and soap if available) immediately to remove the oil from the skin. If rash develops, oatmeal baths, calamine lotion or Burrow's solution may be helpful for symptomatic relief. Creams and ointments that contain benzocaine, zirconium or antihistamines should be avoided because some people are allergic to these ingredients.
Oral antihistamines, like Benadryl, may help relieve itching.
A person should seek medical treatment if the rash is widespread, near the eyes, if he or she has an underlying skin condition such as eczema or psoriasis or if the rash is not resolving after a week.
More information about poison ivy is available at www.aad.org.