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Super Lice Like Selfies!

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Super Lice Like Selfies!

The problem of head lice infestation is an ongoing struggle and worry for many families.

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These insects have become more resistant to treatment in 25 states, and Florida is one of the states with the most treatment challenges. Each year in the United States, about 12 million children are infested, and the total yearly cost of treatment for Americans is estimated to be about $1 Billion per year.

So what are these bugs, how do they spread, and, most importantly, how do you get rid of them? Lice are wingless insects about 2mm long (about half the length of a grain of rice) with 3 pairs of legs that have little claws at the end to grab onto hairs. Head lice (pediculus humanus capitis) are white/gray in color, and they crawl fairly quickly, but they do NOT hop and they do NOT fly. Head lice do not spread diseases.

Mature females lay as many as 10 eggs a day, and they prefer to place them behind the ears and in the back of the head. The eggs are less than 1 mm in size and are attached to hairs with a natural glue. The eggs are usually referred to as nits, and they are placed very close to the scalp, within 2mm, where it is warmer. The eggs need warmer temperatures to mature, so that is why lice problems are worse in warmer climates, such as ours in Florida.  Dandruff is often mistaken as lice infestation, but dandruff flakes will travel farther out on the hairs and will not be adherent to the hairs. The eggs hatch in 8-9 days as nymphs, and the nymphs mature to adults in another 9-12 days.  The adults live for about a month.

Okay, here’s the unpleasant part.  Head lice feed on blood. They pierce the scalp and inject saliva to feed, and this is what causes the itching.  Typically they feed about 5 times a day. A live louse cannot live without feeding for more than 2 days, but the nits can survive away from the scalp for about 10 days, sometimes even up to a month. 

Most cases of head lice are contracted by direct contact with an infected person. Although many people worry about sharing combs, brushes, hats, and other things, these are much less likely to spread the problem. Lice infestation has NOTHING to do with cleanliness or personal hygiene.  Hair length and frequent shampooing have no effect on the risk of contracting lice. Caucasions are more likely to contract lice because their hair is a better size for the claws of the lice and because of the thick emollients used in the hair by many African Americans.

Children between the ages of 3 and 11 are the most infected, likely due because they are more often in close contact with one another.  Most infections, contrary to popular belief, are not caught in schools.  Most often it is live insects, not the nits, traveling from one person to another, so you may want to think twice next time you take a selfie head to head with a close friend!

Okay, so once you are dealing with head lice, what is the best way to get rid of them? Ideally the treatment would be easy, safe, effective against live insects and the nits, and inexpensive. There are home remedies, over the counter medications, and prescriptions.

We have all heard about using mayonnaise, olive oil, petrolatum (Vaseline) and other greasy treatments to suffocate the lice, but these have not been proven to work, and they would not kill the nits. One limited study used Cetaphil cleanser applied to the hair, dried with a blow dryer, rinsed in the morning, and repeated weekly for 3 weeks, but this study has not been substantiated yet. Gasoline and kerosene are NEVER appropriate and can be toxic and dangerous.

Over the counter medications, including permethrin 1% (Nix) and pyrethrins plus piperonyl butoxide (Rid) have been used for two decades.  Nix is not ovicidal (does not kill eggs). It is applied to damp hair after washing with a non-conditioning shampoo and rinsing. It is left on for 10 minutes and rinsed out. Repeat treatment in 9 days is optional to kill any nits that have hatched. Originally almost 100% effective in 1990, Nix often does not kill the Super Lice we deal with today, working less than half the time. Rid is less often used due to more allergic reactions.  It is applied to dry hair, it does not kill the eggs, therefore requiring retreatment, and resistance is also very common.

Many people end up relying on prescriptions from their doctors. A number of newer choices are available to treat these Super Lice.  Malathion 0.5% (Ovide) was introduced in 1999 and is safe 2 and up. It kills live insects and the eggs, and it is applied to dry hair and left on for 8-12 hours before rinsing.  One treatment usually works, although resistance has been reported. Retreat in 9 days if live insects are seen again. But be careful! Ovide has a high alcohol content, so do not dry with a blow dryer or apply a curling iron, and certainly do not smoke near the child, because it is very flammable.   

Benzyl Alcohol 5% (Ulesfia), has been available since 2009 and can be used 6 months and older. It is fairly effective, though not ovicidal, but it often causes scalp irritation. It is applied to the scalp and entire length of the hair and rinsed after 10 minutes. But keep it out of the eyes, because it will cause irritation.  It is effective about 75% of the time and also requires retreatment.

Available since 2011 to children 4 and up, Spinosad 0.9% (Natroba) kills bugs and eggs, and it works about 85% of the time. It is applied to the scalp and entire length of the hair and rinsed in 10 minutes. Retreatment is done in a week.

Ivermectin 0.5% (Sklice) is well-tolerated, approved age 6 months and older, and works about 74% of the time. Introduced in 2012, it is applied to dry scalp and hair and rinsed after 10 minutes and a single application is usually all that is needed.

Whatever product you use, be sure to read the directions carefully. Remember that wet combing after treatments to remove nits is always recommended and can increase the chance of cure dramatically. Itching can be treated with topical cortisone or selenium sulfide shampoo.

There are other prescriptions not currently approved, such as topical permethrin 5% and crotamiton 10%, but safety has not been established, so they are not yet available.

Other unapproved treatments (considered off label) have been used with varying effectiveness. Oral ivermectin, sulfamethoxazole-trimethoprim (Bactrim) have been used with some success, especially when used in combination with topical treatment. But these are not well studied at this time.

Treatment failure was previously thought to be due to incorrect use of all these treatments, but now we realize that true resistance of these Super Lice is a real problem.  Wet combing with a lice comb every few days for 2 weeks can be an effective way to remove all the nits and solve the problem.  There are lice treatment facilities now available for a hefty price, adding up to as much as $300 per person, but they can be very effective.  Some facilities have trained personnel that carefully nitpick every egg, and others use a special dryer that is used to kill the lice and eggs and can be quite effective, especially if the nits are also removed to ensure a cure.

Control of spread is a key part of treatment. Once one person in a household is diagnosed, all members should be checked. Treat anyone who is infested, but not those who are clear, and consider treating anyone who shares a bed with the infested person. The Centers for Disease Control (CDC) recommends washing combs, brushes and similar items in water over 130 degrees then consider putting them in plastic bags for 2 weeks. Wash bedding and clothing in hot water and dry on the highest setting. Vacuuming furniture and rugs may be a good idea.

What about ‘No Nit’ policies in schools?  Are they necessary? The American Academy of Pediatrics recommends against the exclusion of children with nits but no live insects. They cite research showing a low risk of spread when there are no live insects, and these policies have caused children to miss millions of days of school unnecessarily. More importantly the children should be encouraged to avoid head to head contact, and confidentiality is important for those infected to avoid any social isolation.

Fortunately, we now have a number of options to try to fight off these ‘Super Lice’. For more information, call your doctor or go online and read the AAP review at http://pediatrics.aappublications.org/content/135/5/e1355 or visit the CDC at http://http:/www.cdc.gov/parasites/lice/head/treatment.html.

 

By Andrew Sinder, MD

Jacksonville Pediatric Associates

http://www.jacksonvillepeds.com

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