The Facts of Lice

By Dr. Gregory Gordon
gregorygordonmd.com
Author of Raising Good Parents – A Guide to Your Baby’s First Year

by Dr. Gregory Gordon

by Dr. Gregory Gordon

I remember getting lice as a child. My mom was uncertain of the diagnosis, so we marched two houses down to the home of a good friend and third-grade teacher. She carefully combed through my brother’s hair and confirmed he had lice. When it was my turn to be checked, close inspection was not needed. She could see my lice six feet away! Our parents treated us with an over the counter shampoo and washed our sheets and clothes. I don’t remember extensive nit combing or worrying that the treatment might not work. My mother recounted horror stories of when her sister had lice in the 1950s. Over the counter shampoos were not available, so my grandparents shaved her head and burned her clothes.

Unfortunately, the treatment of lice has only become more complicated. Over the last 25 years, lice have developed resistance to many common treatments. Over the counter shampoos that always worked still work, but only “most of the time.” As lice resistance has increased, so have parental concerns about these insecticide shampoos. And those concerns have led many parents to partially treat or try untested treatment methods. In response to parental concerns and traditional medication treatment failures, pharmaceutical companies have developed several new treatments. These medications are more expensive, but generally offer increased effectiveness.

Head lice, medically pediculosis capitis, is estimated to infect six to 12 million children each year in the United States. Transmission of lice is almost always by direct head to head transmission. Rarely, they can be carried on brushes, combs or towels. Adult lice crawl, they do not jump or fly. Cats and dogs cannot be infected and do not spread lice.

Adult head lice are 2-4 mm in size. They need to feed on human blood several times a day to survive. Females live for three to four weeks and lay an average of 10 eggs each day. Eggs, also known as nits, are only 0.5 mm in size. The eggs are laid on the hair shafts about one cm or less from the scalp. The scalp provides the heat needed to incubate the eggs. The nits are “glued on” and cannot easily be moved. This characteristic is the easiest way to distinguish them from dandruff or other items trapped in an individual’s hair. Nits are most often laid at the back of the head, especially behind the ears. The eggs usually hatch after eight to nine days.

Yeah, now you're itchy!

Yeah, now you’re itchy!

The majority of lice cases are treated by parents at home with over the counter medications, good nit combing, or home remedies. My nursing staff advises parents on lice diagnosis and care daily. As a pediatrician, we only get involved when standard treatments fail. Consequently, my knowledge of lice and lice medications has been focused on the newer prescription medications.

Then it happened – our family got lice!

My wife and I went into “skeved-out lice panic” mode. We knew that treating a family of ten would be extremely difficult. A few missed nits could mean starting all over. Outfitted with headlamps, reader glasses and metal nit combs, we searched through our children’s hair. We found live bugs on four of them.

There is a current controversy in medicine, whether to “treat everyone in the family” or “treat only those with live, active lice.” But in our high-density situation, we chose to treat our whole family with an over the counter medication. We followed up with nightly nit combing (several hours each night) and bed-sheet washing. After several days, my wife and I were physically and emotionally exhausted. Then we re-treated the family seven days after the initial treatment.

Three months later, we found a small infestation in two of our daughters. We are uncertain if these were either the product of unfound nits or re-infestation from a friend with known lice. Exhausted and disappointed that our initial super-parent efforts had not work, we chose to re-treat with a newer, more expensive medication. We treated only those with active lice infestations (two of our daughters and their friend). And since then, we have been lice-free.

Whatever I’ve learned, there is no perfect lice medication. Many internet experts argue that medicated shampoos are not needed. Nit combing alone or occlusive therapies are commonly recommended alternatives. The data on nit combing alone reveals mixed data, and while there is some evidence that occlusive treatments like mayonnaise or Vaseline may help, it is certainly not convincing. Shaving an individual’s head is still the most effective non-medical alternative.

Over the counter medications like RID (pyrethrins with piperonyl butoxide) and Nix (permethrin 1%) do work, but have draw backs. They only cost $10-$20, but they require more rigorous nit combing, have the potential for resistance and require re-treatment seven days later.

Prescription medications like Sklice (ivermectin lotion) and Natroba (spinosad) also have a role. These medications are one-time treatments, but are expensive, costing $90-$280.  Both of these products have solid research to support their effectiveness even without nit combing.

In my opinion, nit combing is essential. All experts recommend combing to remove the nits. There is even some evidence that nit combing alone can be effective. Shampoo medications should kill the adult lice, but no medication kills 100% of the nits. For effective nit combing: wet the hair (slows down the bugs), use “reader glasses,” a bright head lamp and a fine-toothed metal nit comb.

Don’t celebrate too early. Too often, parents quit combing and monitoring after a few days. Unfortunately, nits are often missed, and after 8 to 9 days they hatch and create a second infestation.

 

Dr. Gregory Gordon

Dr. Gregory Gordon

Dr. Gregory Gordon grew up in Gainesville, Florida. He attended the University of Florida for both his undergraduate and medical degrees. After he completed his pediatric residency at the University of Alabama at Birmingham, he joined Pediatric Associates of Orlando. Dr. Gordon is the proud father of eight children. He is the Vice President of “The Gift of Swimming” (a local charity that provides swim lessons to Orlando’s needy children). In early 2010 Dr. Gordon started gregorygordonmd.com to share his pediatric and parenting experience.

 

Originally posted 10/13/2014

1 Comment

  1. I have heard stories of people having to get their heads shaved when they got lice, but I am really glad that that never happened to me. My parents ran a foster home and so lice was a very common problem and so we couldn't always afford to get the special shampoos either. However, she always washed our hair out with mayonnaise to solve the problem. http://www.licetreatmentgroup.com/es/services

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