I recently received a phone call from a distraught mom who was thoroughly frustrated over trying to rid her daughter, Stacey, of head lice. Three times she treated her daughter's scalp, and three times she was sent home from school with lice. I listened carefully as she detailed every step she took in trying to eradicate the pest. Sure enough, she followed the directions to the letter, including boiling the combs and brushes, washing the bed linens, and discarding her head bands. Within days of treatment however, the lice were back as if nothing had been done.
Much has been said recently about a serious problem facing health care workers--resistance of bacteria to the antibiotics that were once a dependable mainstay of medicine. In the past few years, bacteria such a streptococci and staphylococcus have developed resistant strains that are not responsive to even the newest antibiotics. This poses a real threat. Is it possible that the pest, Pediculosis humanis capitis (head lice) too, has become resistant to the standard treatments? Regrettably, the answer is yes.
Head lice is a small 2-4 mm parasite that lives in the scalp hair of humans. They feed on human blood, and the females lay around 3-10 eggs per day. The eggs are encased in nits, tiny 0.5 mm "capsules" that become cemented to the hair shaft. They are visible to the naked eye. The nit remains attached to the hair even after the egg hatches. Lice cause intense itching and irritation of the scalp, and can cause a secondary bacterial infection of the scalp.
The treatment of choice for lice includes shampooing with a 1% permethrin shampoo and leaving it on the hair for 10 minutes before rinsing. This can be repeated in 7-14 days to kill the eggs that may have subsequently hatched. The remaining "dead" nits must be mechanically removed because they will remain fastened to the hair even though they are not alive. They can be combed out with a fine-toothed comb, or picked out by hand. Clothing and bed linen must be washed in a hot cycle, and combs and brushes should either be discarded, or boiled after treatment with the 1% permethrin for 15 minutes.
Recent studies suggest that a new strain of lice has emerged that is unfazed by 1% permethrin. When put in a petri-dish on a piece of gauze that has been soaked with 1% permethrin, the lice were untouched. When placed on 5% permethrin, only a small number of the lice succumbed. This was both perplexing and distressing to researchers.
This new resistant strain seems to have originated in the Middle East, and has caused outbreaks in Florida. Health care professionals are worried because of the implications. Head lice has long been a problem in schools throughout the country. Eighty percent of U.S. school districts had at least one outbreak of head lice during the 1996-97 school year.
One article that appeared in a pediatric newsletter titled "Head Lice From Hell Aren't Going Away", discusses some of the household remedies that physicians and school nurses were using in Florida to combat the lice. One doctor has his patients apply a "good sized glop" of petroleum jelly on the scalp--enough to cover every hair. Then he has them wear a shower cap overnight. This asphyxiates and kills the lice. The only problem is that it takes a good week of daily showering to get all of the jelly out of the hair.
Other "less sophisticated" approaches mentioned were shampooing with mayonnaise, margarine, or olive oil followed by vinegar. These should be discouraged lest you want to have a child that not only has head lice, but smells like a salad.
There is a new product that looks like it might be promising. It is called HairClear 1-2-3 and is made by Quantum Inc. of Eugene, Oregon. It is made of anise oil, ylang ylang oil, coconut oil and isopropyl alcohol. Until clinical trials are completed to study it's effectiveness, it is not yet approved by the FDA for the treatment of lice, however, anecdotal accounts by many physicians tell of it's success.
Fortunately, we have not had the problem of resistant lice here in Southern California, although it is probably just a matter of time. For now, the 1% permethrin seems to be the treatment of choice at least until newer products are available.
As it turned out, Stacey did NOT have resistant lice. After doing some detective work and obtaining a detailed history, we found the culprit. It seems that Stacey always leaves her baseball cap and glove in her mom's car after practice or games. While mom methodically scrutinized everything in the house that might have served as a reservoir for the lice, she didn't even think of the baseball cap. Every Tuesday and Saturday when Stacey would go to her practices or games, she would re-infect herself. After getting rid of the baseball cap (mom burned it), and one final treatment with 1% permethrin, the lice was gone for good.