About 10 years ago, there was a major lice bloom around some friends in western Mass. They were initially infected by exposure at school, as is most common. As a large group household, however, with 7 adults and 4 kids as permanent residents, and uncounted visitors, they were having a nightmare time trying to keep from being reinfected,
The following came from a rather brilliant genomic scientist friend, whose family was hit by a similar series of infestations and reinfestations not too long before my more-local friends. I leave his first name attached, but I stripped out everything else identifying, as this was sent in a chain of personal correspondence, albeit with a long list of recipients.
Hey You All,
This is my download on everything I've learned and researched on the subject of head lice.
firstly, there is a web site that has some information about head lice that is worth looking at. we ordered a good video from them:
you will discover these guys are trying to make money like everyone else so don't get too caught up with their comments on: "Reports of pediculicide-resistant lice are on the rise!". however, they have some good information on the growth cycle of the louse.
the louse life cycle
you MUST understand the growth cycle to work out a sane plan of knocking back lice. see http://www.headlice.org/faq/lousology.html for a great picture of the lice life cycle.
Nits (the eggs of the head louse) are small yellowish-white, oval-shaped eggs that are "glued" at an angle to the side of a hair shaft. they look like small pearls on the side of hairs. to distinguish from a piece of dead skin, otherwise known as dandruff, and a nit, yank the hair, then carefully use a piece of scotch tape to try to stick to the nit. if that pearl does not come off easily, then honey, you got nits.
Nits must be laid by live lice. You cannot "catch nits." Once laid, it takes 7-10 days for a nit to hatch, and another 7-10 days for the female to mature and begin laying her own eggs.
Head lice are clear in color when hatched, then quickly develop a reddish-brown color after feeding.
Head lice are about the size of sesame seeds. However, you will virtually NEVER see a louse because they move way, way too fast. Typically the only time you will be blessed with seeing an adult louse is when its dying from anti-louse detergent/insecticide.
Head lice have six legs equipped with claws to grasp the hair.
Nits tend to be found in the hair on the base neck, and behind the ears. Accomplished nit finders usually check there to quickly identify an infestation.
Head lice are small, wingless insects which feed on human blood. They need human blood in order to survive.
Head lice live for approximately 30 days on a host and a female louse may lay up to 100 nits (eggs).
How long can head lice survive off their human hosts? Depending on who's doing the telling, you'll hear lengths of time varying from 12 to 48 hours. Basically, head lice living off their human hosts are starving ... and, as with any organic being, starvation eventually causes death. However, also as with any organic being, metabolic rates vary and death of the head lice by starvation will occur at different rates from individual louse to individual louse. The NPA suggests that, in most cases, a head louse will not survive for more than 24 hours off of its human host.
Itching heads are a very very poor measure of infestation. Itching will alert you that your kids may have lice, but continues WAY after de-infestation. To stop itching is virtually impossible once the host becomes aware of the possibility of being infected -- even when truly not infected. No joke, writing this email is making me itch.
know the enemy
Why the understanding the life cycle matters: because the fact is that any article of contaminated clothing, if isolated longer than the combined length of time an adult or nit can live, that bug dies. three weeks of isolation and they be dead.
The other fact is that no louse can live through a thorough trip through the clothes washer and dryer when both are set on their hottest settings. So save yourself a lot of time and hysteria by bagging up all the pillow cases and sheets and pillows and hats and simply isolate them. For clothing you need right away, remove from an infected body, wash in hot water and hot dryer, and go on some program of killing the little guys.
Understand also that if you could always kill -all- the lice on your body, you simply would not have to decontaminate your house, because lice can not complete their life cycle with out a human host.
The other reason you must remain aware of the life cycle is because it has a lot to do with how people get burned when they are systematically trying to remove lice from their lives.
Observe: Nits are laid by live lice. Once laid, it takes 7-10 days for a nit to hatch, and another 7-10 days for the female to mature and begin laying her own eggs. what that means is what ever eradication program you engage in, you must continue diligence for removal over the time period that a nit can hatch -- 7-10 days. insecticidal soaps work, its just that if you use them they kill -most- of the adults, and even less of the nits! so eradication is a process of assuming that some nits may hatch, even after thoroughly clobbering you and your children with an insecticidal soup (or whatever). you must continue to try to catch lice during the stage when they are easier to kill -- that is after they hatched and they are an adults -- after de-lousing with an insecticide.
basically, a program of trying to kill adults once every 3-5 days works. you could stretch that out to every 5-7 days, but I worry that some robust, rogue, pregnant female will prevail and start dropping a few hundred nits.
things that kill
kill kill kill. things that kill adult lice:
vinegar. thats it. boom. dead. if you run into an adult louse that lives through a treatment of vinegar directly applied to your head I personally would like to share a few words with that insect. vinegar probably also kills the nits, but there is a chance that a few hardy ones could make it. kids do not like vinegar.
olive oil. note: if you take a live, fertilized chicken egg, cover it with a layer of vaseline, the chicken embryo will die. the reason is that the embryo must respire and it does so by allowing air to pass thru the shell. the embryo will die if it is not possible to respire. in the same way, a coating of oil on a nit will prevent air passing thru the outer layer of the egg and you will kill that nit.
yah, so, no kidding, when I was trying to eradicate nits on my head I did a daily oil and vinegar treatment. at night, I would apply a coating of oil to my head, wrap a torn up sheet around my head, sleep, and then wake up and wash my hair. after washing the olive oil out of my hair, I would apply vinegar while still in the shower and then wash. heat. a blow dryer is very definitely a very intense heat. blow drying your hair will greatly reduce the chance of adults surviving on your head. like I mentioned they don't live through a trip through a hot clothes washer and a hot clothes dryer. but when you start thinking about this stuff, you realize the only real problem is removing lice from yourself, not your environment.
insecticides. do not be afraid of insecticides. yes, avoid lindane. if you read around you will find various pieces of information that say insecticides have some dangers. I don't buy it. first of all, many of the sources of that information are trying to sell you something else. secondly, the logic that you can buy something that is 0.02% permithrin at the pharmacy that has a label that reads: use only once every two weeks, and yet you can go to a doctor who will give you something that is 0.5% permithrin and its label says: do not use frequently just doesn't fly for me. the labels in the pharmacies are to prevent the clueless from drinking the stuff. fine. don't live in it or coat your bagel with it. permithrin, just so ya know, is derived from the plant, chrysanthemum.
cat mousse. that's right. cat mousse. there is a great veterinary medication that has precisely the same active ingredient as the commercial insecticidal soaps for humans and its significantly cheaper. read the label and compare. you'll see the mousse has a similar strength, in fact a rather strong percentage, that is rubbed into the hair and left there. when I was at a point where I was traveling this stuff was an incredible life saver. if exposed again, I personally would use this first, once every 3 days for two weeks, rather than any other silliness. but that's me and I must say I'd have some misgivings about using it on children.
moth balls. moth balls may not kill them dead in their tracks, and I do not recommend them as ear-rings, however, one thing that moth balls do is help with is clobber them in areas that are hard to get at. I kept them in the vacuum cleaner because I was worried they could get vacuumed up, and have a nourishing meal of skins cells inside the vacuum that might prolong their life-span. I strongly recommend leaving one or two mothballs in the garbage bags that you may choose to use when you are isolating clothes and pillows. one moth ball in a drawers or shelves with clothing or towels is also recommended, and should help the little darlings rush to meet their next kharmic destination as motor vehicle employees.
nit removal. diligent removal of nits by the use of a nit comb can help a lot and this is not as effective as putting your head in the microwave. it takes practice, and you have to be thorough. once you see what a nit looks like, you can engage in the joys of trying to remove a nit from a hair stalk with a comb -- its not easy. what the comb really does is just help make it easier to pick a section of hair, and look at that section really carefully. (I really liked to run a nit comb through my hair because you could at least take "a sample" in that, if after a lot of combing, you find the little pearls in between the teeth of the comb you knew if you had lice). special trick: to pull a nit from a hair stalk put a piece of scotch tape around your finger with the sticky side pointing outwards -- then you use that to stick to the nit. when working wash this comb in hot water or alcohol or vinegar, to kill 'em as you go.
I realize these are brief but you guys got what it takes to figure out a more elaborate strategy.
if you want try some over the counter insecticidal soap:
wash some clothes so you know they are uncontaminated. do the soap strategy with yourself and your children. put on the trustworthy clothes. use trust worthy towels. have some adults make their best effort to start running the nit combs through the children. have some other adults try to clean up the possibly contaminated areas.
but seriously, you. have. got. to. kill. surviving. nits. it just doesn't work to assume that one application takes care of the problem. I believe in the regular application of insecticides on a periodic basis (I'd use 3-5 day intervals). stretch it out to just two applications if you want, but you have got to work significantly harder on removing nits using the comb. I like the better living through chemistry strategy: regularly applied insecticides means you can work much less harder on picking nits with a comb.
oil and vinegar:
if I were you guys I would have the adults go with cat mousse, and the children get oiled at night, and wash with vinegar in the morning. pick, pick, pick regularly with the comb. decontaminate clothing, bedding, and towels as above, but what its really about is killing them on the head. adults that don't want to do cat mousse can go with insecticidal soap, or olive oil. hey, oil does wonders for your hair I'd recommend it to the adults too.
oil is applied to the -scalp-. not the hair. this is because the adults are traveling on the scalp, and you kill them, and the freshly laid eggs with they put on at the base of the hair. you can see eggs further up the hair stalk -- why? -- because your hair grew! in those cases, yah sure, apply oil everywhere.
I recommend an overly cautious strategy of oiling every night, or every other night. other sources recommend 3-5 days. after a while it is just not that big a deal and it was easier for me to do it often rather than pay attention to the calendar.
for some reason, I am concerned that only vinegar will not work, which is kind of an intuitive thing, and because it may be that nits can still live through vinegar.
- cat mousse for everyone! like I said, if it was simply up to me, I would go with cat mousse every night, and that's it. no combs, no washing. but I leave that up to your discretion. life is a risk, and judging if a certain chemical has more risk than another, is something of a silly game. I suspect that I experience far more long term damage from drinking, than I ever will from using something with permithrin.
sane practices to reduce possible re-infestation
this is a slow, logical, -reduction- of little insects in your life. you will absolutely not be able to completely rid them from a household, unless the infestation was fairly small to begin with. follow these practices to reduce their chance of survival:
- its really rather rare that you can get re-infested from the environment, its much more likely you get it from nits that made it through some decontamination cycle and you let them live long enough to lay more eggs. so comb heads regularly, use a blow dryer, and cat mousse or oil.
- use hot water during cloth washes.
- use the dryer.
- vacuum the house regularly.
A public health-care worker once told me with a lot of certainty that head lice rarely infect adult males. Well, um, maybe it was my inner child.
Pets do not get head lice.
Long hair should NEVER be cut to prevent infestation. [A young lady with two feet or more of hair] had them, and she survived just fine.
Head lice are crawling insects. They cannot hop, jump, or fly.
Infested persons do not always experience persistent itching.
Lice are not found in dirty, poor environments. Forget it guys, do not give yourselves a hard time because you have a case of lice in your household. Lice don't discriminate and they actually people who use cleaner hygiene practices than those who don't. They infect people from all socio-economic backgrounds. Children are their usual victims and lice are typically brought home from schools or daycare.
You are not being smote by god or your ex-boyfriends.