There is probably nothing more feared at the beginning of the school year than the head louse. This tiny, sesame-seed sized insect has been known to put school nurses, administrators, parents and boards of health into a state of panic. Why all the fuss and bother? Do head lice truly represent some kind of health crisis? Do they carry disease? And how can we be rid of them?
What about lice?
Much of the loathing associated with head lice is probably misdirected from its cousin, the body louse. Body lice are very different from head lice and are signs of uncleanliness and unhealthy living conditions. They are known carriers and transmitters of diseases, notably typhus and trench fever. Body lice are still a scourge in America, principally among the homeless and those living in very substandard housing.
The bad news about head lice is that they are much more prevalent than body lice, affecting six to 12 million Americans each year, according to the Centers for Disease Control and Prevention. The good news is that head lice have never been shown to transmit any diseases. Nor are head lice an indication of poverty or substandard living conditions; "cleanliness has absolutely nothing to do with lousiness," according to Richard J. Pollack, PhD, Harvard School of Public Health.
What about other head lice myths?
Head lice breed in the furniture or in the carpet. No. Head lice depend on their human host for their food, warmth and shelter. While they can leave one human for a couch and then crawl onto another human's scalp, they cannot live more than 24-48 hours off the human scalp.
Head lice prefer long hair.
Head lice carry disease.
How is it diagnosed?
Be careful though -- dandruff and other scalp debris (such as unrinsed conditioner, etc) -- can appear as whitish dots on the hair. The lice casings are stuck tightly onto the individual hair shafts, and are not easily removed. Also, as mentioned above, the nits to worry about are the ones closest to the scalp; any further than a 1/2 inch from the scalp may be left over from a prior event.
The only way a true diagnosis of head lice infestation can be made is by seeing a living louse. The best way to do that is wash, condition (it makes the hair shafts slipperier) and then towel-dry the hair so it is damp, but not dripping. You will need a lice comb (metal or plastic with very closely spaced teeth -- 0.2-0.3 mm).
Find a well-lit space. Comb the hair first thoroughly with a regular comb to remove tangles, etc. Then with the lice comb, start at the scalp and work to the end of all the hair, working in sections to make sure you get every hair. After each pass, examine the comb or wipe it on a white paper towel. If head lice are present, you should be able to trap one with the comb using this technique.
Interestingly enough, those who do have an infestation probably only have about a dozen insects in their hair at any one time. Remember, lice do not have wings, so if you come up with a winged insect, you probably want to get rid of it, but it isn't a louse. If you don't find a louse, but you do find eggs or nits close to the scalp, you should repeat the process in a day or two. The experts recommend that no one be treated if no live lice are found.
How to treat
Brand names include RID, A-200, R & C, Clear, Tegrin-LT and Pronto among others, and they are available as mousse, gels, liquid, and shampoos. NIX contains 1 percent permethrin which is a synthetic pyrethroid formulated into a creme rinse. For very resistant cases, there are also prescription remedies, notably malathion 0.5 percent lotion (Ovide) and the most toxic of the remedies, lindane 1 percent (Kwell and other brands).
But everybody says those OTC products don't work all that well, Right? So why not save time and money and go right to the prescriptions? The fact is, if the OTC preparations are used correctly, they are very effective and safe. If we've got to do this treatment, let's give ourselves the best chance of success by taking time to do it right the first time.
Some formulations will require a second applications seven to 10 days later to get some lice that may have been protected by their egg cases. Reapply only as directed on the package label.
Remember all of the above medicines are for external use only, and are not to be put in the mouth! Keep these and all medicines out of the reach of children.
What about "home remedies?"
In the "As-yet-unproven" category we find the applecation of dense substances such as mineral oil, petroleum jelly, margarine or mayonnaise in an effort to smother the lice. In addition to then taking days to rinse out of the hair, these substances would not kill the eggs and would need to be repeated in seven to 10 days. Also unproven is the use of oral antibiotics to kill some of the body's intrinsic bacteria that produce nutrients that might help the lice.
From the "Potentially dangerous" file are many of the Internet-available remedies containing ingredients advertised, but medically unproven, to be natural insecticides. Some products have been shown to be irritating to the scalp and, as with all medicines, many are dangerous if ingested. Unfortunately, just because an ingredient is "natural" or found in nature doesn't make it safe; arsenic and hemlock are "all natural." Check with your healthcare provider for his or her recommendations for alternative remedies.
And from the "Definitely dangerous and foolish" category comes the application of any dangerous substances such as kerosene, gasoline, bleach, acetone, turpentine or motor oil.
Scouring the house
What about others in the house?
What is a "No Nit Policy" and is it worthwhile?
A study by the CDC found that only 18 percent of children with nits in their hair developed lice within the next two weeks. Neither the American Academy of Pediatrics (AAP) nor the National Association of School Nurses (NASN) believes in the "no nit" policy. The AAP reports that "Children identified as having...head lice should be excluded from school only until treatment has been started. School contacts generally should not be treated prophylactically." And the NASN concludes that, "Nit-free policies disrupt the education process and should not be viewed as an essential strategy in the management of head lice."