Here's a head-scratcher: how can something so tiny create such massive misery? Minuscule though they are, head lice still can wreak months of havoc on a household. My own grandchildren have played host to these persistent parasites -- which have a way of withstanding repeated comb-outs and drenchings with powerful insect-killing shampoos.
While lice have a high ick factor -- bet your own scalp itches as you read this post -- the bugs themselves are fairly harmless. They don't carry diseases. They just really gross most of us out.
Lice have annoyed and fed on us since antiquity. The Centers for Disease Control estimate that among 3- to 11-year-olds alone, there are 6 million to 12 million infestations a year. While there are plenty of products to combat lice, these frustrating critters have grown increasingly resistant to common remedies, necessitating repeat treatments.
Itching and Scratching as Signs of Lice
For grown-ups, the first heads up of lice woes likely will be a child's persistent itching or frequent scratching. That lice-related kid clawing can be traced to an allergic reaction to the bite of these bugs, which thrive on human blood. While the bites themselves don't cause disease, the scratching can lead to irritation and infection.
The gold standard for identifying a head lice infestation is to spot an actual, live louse or a nymph -- a newly hatched louse. This is tougher than it sounds.
Full-grown lice roughly are the size and shape of a sesame seed, white to reddish-brown in color and have claws designed to let them cling to and rapidly navigate the hair.
This is why lice detectives, in general, rely most on the second-best infestation evidence: nits or louse eggs. These easily can be confused with dandruff or specks of dried hairspray. But unlike those common scalp debris, these tiny white blobs won't easily fly away when flicked. Nits a quarter-inch or so down the hair shaft may indicate an infestation. Nits tend to be found clustered by the hairline at the neck's nape or behind the ears.
Once you've confirmed head lice as culprits, the battle just begins. A number of over-the-counter treatments are available for exterminating lice, though there is a growing concern that the creatures are becoming resistant to common remedies like permethrins (which are in the product Nix) and pyrethrins (carried in R&C and Rid).
It's unclear just how prevalent is the lousy resistance to specific products; it's often regional. Because over-the-counter pediculicides have been proven in studies to be safe, and they usually are effective, they're still a good first-strike medication against the pests.
After De-lousing, Follow Up
While the products kill lice and nymphs, none can kill 100 percent of the eggs. If those survive and hatch, the infestation begins anew. So it's important to keep checking for live lice after the initial treatment. Repeat treatments often are recommended a week to 10 days after that first go. In persistent cases, pediatricians can recommend prescription-strength medications such as malathion lotion (trade name Ovide), benzyl alcohol lotion (Ulesfia) or lindane shampoo (Kwell).
After killing lice, adults should comb youngsters' hair carefully to remove vermin and eggs. All family members should be checked and treated if necessary. Eradication can be laborious: Once a family is de-loused, their environs must be treated, too. Wash or dry clean all clothes and bed linens. Storing stuffed animals and comforters in a plastic bag should kill both lice -- which die within a couple days without human blood -- and eggs. Vacuum the floors and furniture. Combs and brushes should be sterilized or replaced.
It's an unpleasant way to have to spend a beautiful weekend -- but if all these little nuisances get nabbed the first time around, you may be spared repeating the process.
There's another treatment option: a machine called a LouseBuster. Its single, 30-minute application of hot air has been shown effective in killing all eggs and 80 percent of hatched lice in test infestations. The device is pricey and requires a trained operator. Don't think your regular hair blow-dryer will work in similar fashion -- not only won't it kill your lice, it will jet them into the air, all the easier to spread.
Besides causing excruciating itching for infested youngsters, lice also can be blamed for chagrin and high anxiety among parents of many kids in elementary schools across the country. Let me assure you embarrassed moms and dads who have kids with lice -- no, the infestation isn't a reflection on your home's cleanliness or grooming, nor your parent skills. It's not the dog's or cat's fault, either -- pets play no role in spreading lice. These critters just happen to be incredibly common and they spread easily -- by head-to-head contact and sharing of clothing, hair-grooming items, blankets or even furniture.
Best Practices for Schools
The annoyance and concern over lice, however, has gotten so intense that many schools have adopted "no-nit" policies. The Los Angeles Unified School District scrapped its version of this, in favor of a "no-lice" policy. This means that children with a confirmed infestation shouldn't come to school until it has been treated -- but the presence of nits alone isn't reason enough for youngsters to miss valuable school time.
That's in keeping with the American Academy of Pediatrics' views. In a report published last year, the academy noted that screening for nits didn't have a big effect on the number of infestations. A study of more than 1,700 children screened for lice found that only a third of those with nits carried live lice on their heads. Of kids with nits, just 18 percent developed a full infestation during two weeks of observation. Based on this and other data that show youngsters will miss important education time just because of too-rigorous and wrong-headed policies that penalize them for signs of lice and not full-blown lice infestations, the pediatrics academy and the National Association of School Nurses both oppose "no-nit" policies. Experts do recommend nit removal, as it can decrease the need for re-treatment and the risk of self-re-infestation.
Lice happen. So teach your kids smart behaviors -- avoid head-to-head contact while playing and don't share clothing, brushes, combs, towels, hair ribbons or barrettes. When you get the dreaded note from school or daycare, or see the telltale scratching, don't panic. If it's any consolation, lice actually prefer clean heads and hair.
Follow Glenn D. Braunstein, M.D. on Twitter: www.twitter.com/CedarsSinai