DEAR DOCTOR K:

My 19-year-old daughter is in college, and she recently told me there had been an outbreak of body lice in her dorm. She didn't get them herself, but I'm still afraid she'll bring them with her when she comes to visit. What can you tell me to calm my fears?

DEAR READER:

Your chances of getting body lice are slim. I'll discuss why, but first let's talk about what body lice are and how to deal with them if you get them.

Body lice are small, parasitic insects. They live mostly in a person's clothing or bedding. One or more times a day, they crawl onto the skin to feed on a person's blood. Slightly different types of lice live on the head, the body, and the pubic areas (the male and female sex organs), where they're called "crabs."

Body lice live and breed in the seams of clothing worn close to the body. Because of this, most infestations affect adults who rarely change their clothes. Thus homeless and destitute people are disproportionately affected.

An infestation of body lice often causes intense itching, which is an allergic reaction to their saliva. When they bite the skin to feed on a person's blood, their saliva gets into the bite, and the immune system reacts against the foreign saliva. This reaction may appear as small, weltlike marks and, possibly, redness and swelling, particularly around the neck and on the torso.

Body lice are spread by direct contact with infested people and their bedding or clothing. To prevent infestation, avoid sharing clothes and bedding, and close, prolonged contact with an infested person.

Body lice can be eliminated immediately by bathing and changing into clean clothing. Occasionally, treatment of the affected person's skin with an insecticide is required. The one most commonly used is called permethrin. Many "natural" creams are advocated as remedies; I'd avoid them.

If you get lice on your head or in your hair, combing the hair to remove the lice eggs (called "nits") is important. The eggs attach themselves to the hairs.

Body lice and their eggs can be killed by washing clothing in hot water, drying these items in a clothes dryer set on high heat (more than 122 degrees Fahrenheit for at least 30 minutes). Once body lice are eliminated, skin irritation and other symptoms go away quickly. You can speed the relief by rubbing some over-the-counter (1 percent) hydrocortisone cream on the irritated areas for a few days (it's best to avoid the face).

Now to your question. If your daughter was not infested herself, and if she has been washing and drying her clothing and bedding fairly regularly, it's highly unlikely she could bring body lice into your home. And she would know if she had been infested, since the symptoms cause such itching. So you probably have nothing to worry about.

(Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: www.AskDoctorK.com.)

** ** **

COPYRIGHT 2012 THE PRESIDENT AND FELLOWS OF HARVARD COLLEGE

DISTRIBUTED BY UNIVERSAL UCLICK FOR UFS