LICE 101 FOR PARENTS AND CAREGIVERS
At the beginning of school each year we, as school nurses, are questioned often when there
is a case of lice found at school. Parents want to know how to rid their child of lice as quickly
as possible and want to make sure they won’t “get it again.” It would be so wonderful if it
were as simple as giving parents a correct answer explaining what shampoo to use but it is
just not that easy…
First of all, lice have been around for literally centuries and have actually been found in a
preserved state on mummies when they were unwrapped. There are over 3000 different
species of lice, indigenous to their own host. This means human lice only live on humans,
cattle lice on cattle, bird lice on birds and so on. Pets cannot be part of a human lice problem.
Lice are not a health issue in that no diseases are transferred via lice.
Many of the pesticide*** and yes, I did say pesticide*** shampoos, over the counter or by
prescription, that are in use as a treatment for lice are now having resistant strains of lice
develop from over use of these shampoos. What this means to parents and caregivers is that
you may use these shampoos and still find live bugs crawling throughout your child’s hair.
Most over the counter types are pyrethrum or permethrin. Medicaid will pay for one
prescription shampoo treatment known as lindane or, more commonly, Kwell. Lindane was
first used as a form of chemical warfare in WWI and one treatment pollutes 6 million gallons
of water. It has been cited in cases of childhood leukemia and seizures in cases of over use
or misuse and has been banned in many countries world wide due to its toxic nature.
Please note that none, and I mean NONE, of the shampoos on the market are going to kill all
the nits or eggs. This is why there is an ongoing problem with lice after a treatment. Even if
the live bugs are not resistant to the pesticide used and succumb to treatment, some to all
of the nits will survive. Once the nymph has matured in the protective shell it will hatch and
begin to feed on the blood from the scalp. This might happen 20 minutes or 12 days after
you “treated” with a shampoo. It takes leaving 2 dark eggs on the hair to “get lice again.”
They hatch, they mature in just a few days, they mate and the entire process starts all over
again. Parents think their child “got it again” but what really occurred is nits were left on the
hair shaft (it only takes leaving 2 nits) to hatch and in the near future itching will resume
and bugs and nits will once again be easily found. One female louse can lay over 100 nits in a
week. Dark nits are a shell with a bug in them waiting on hatching and light nits are just an
empty shell with the bug already hatched. Light nits or empty shells are easy to see on dark
hair but light nits do not indicate an active infestation. It is possible for nits to remain glued
to the hair shaft for years. As the hair grows, the nit is either cut off or the hair is lost
from the head.
The adult female louse lays the nit on the hair shaft as close to the scalp as possible for
incubation. A human loses body heat and humidity through the scalp, assuring that nits on
the scalp are incubated to hatching time. This leads to a discussion about why lice are not
going to infest any building…meaning your home or the school building.
Nits must be incubated to hatch. Humidity like a rainforest and warmth of at least 72
degrees sustained for a period of 8-12 days are needed to incubate nits to hatching.
Without these conditions nits will not hatch. Our homes and school buildings, like other
indoor and outdoor environments, do not have these conditions. Therefore nits or eggs will
not hatch off the scalp.
Baby bugs rarely leave the human host. If you rub what looks like a speck of dirt on the scalp
several times and wait for it’s mouth parts to detach so it can crawl away you have seen a
very young louse. In the rare case of a baby louse getting off the scalp, it would be dead
within 45 minutes from lack of warmth and dehydration.
Adult lice can survive, at most, 48 hours off the scalp without a human blood meal. The
majority will be dead long before 48 hours if a human host cannot be found. This makes it
impossible for lice to “infest” a building. Once your child returns to school on Monday, they
are returning to a lice free building. Just as a school building cannot be infested with lice,
neither can a home or any building…
This is why the Troup County School Nurses do not recommend use of pesticides to treat
the home, car or mattresses. Neither do we recommend that schools use a letter for
classrooms where cases of head lice have been found. Many parents will over react to this
news by ineffective and potentially dangerous “preventative” treatments. In order to
protect children from indiscriminate use of dangerous chemicals to “prevent” something that
these chemicals cannot prevent, we have opted not to send a letter which might be the
cause of a child’s needless exposure to harmful pesticides. Lice are shared by head to head
contact and minimally from sharing hair brushes or sitting on the same sofa or sleeping in
the same bed. Most all schools have someone active with lice from the beginning of the
school year to the end of the school year. The most effective thing you can do is to look
occasionally for lice and the least effective is to use a lice shampoo to PREVENT lice.
Please, before you go to extreme measures that may place your child’s health in danger,
contact one of your school nurses for up to date information.
Other myths associated with lice, besides contaminating your home with needless pesticide
use, is the bagging of stuffed animals and clothes and washing everything in sight. Please
wash the sheets like you normally would. Caution your child not to share combs or brushes
even with siblings and rinse off the lice comb in hot water after each use and you have done
all the environmental controls needed.
Concentrated effort needs to be reserved for what it really takes to get rid of lice and that
is NIGHTLY NIT REMOVAL. This should be done for 30-45 nights without fail. At the end
of this time you will have seen and become able to recognize light and dark nits, baby bugs
that look like a speck of dirt but crawl off if given enough time to detach and move away
from whatever is irritating it, and adult bugs of various stages. This should help your child
become lice free after diligent searches for nits and bugs nightly over this time frame.
Olive oil or mayonnaise will need to be use on a schedule of 1 night on and 2 off, for 7
treatments with the objective to suffocate all the bugs as they are hatching before they
are sexually mature enough to mate and start the process all over again. Apply mayo or olive
oil (if the child is allergic to eggs) generously so that all of the hair and scalp are saturated,
put a beach towel over the mattress and pillow and cover the head with a night cap. Leave
this on over night to suffocate the bugs. Please do not use this during the day. It needs to
be on the hair at least 6 hours minimum to work and is more easily tolerated at night when
the child is asleep. Assist the child in the morning to wash their hair several times with some
type of dishwashing liquid to remove all the oil before going to school and apply a conditioner
to detangle hair. A child noticed itching from lice will have had lice 3-6 weeks prior to
developing an allergic response that causes the itching. Also, once a treatment has been done
(suffocation or use of non-resistant pesticide) and all live bugs are dead and no longer biting,
itching will still present due to the allergic response to lice saliva left under the skin at the
site of the bite. It is much like being bitten by a mosquito.
For boys there is a much simpler alternative to pesticide treatment other than mayonnaise
or olive oil. If they are willing to allow their hair to be cut so short (much like a GI) that it
stands up completely and you can see skin thro the hair of the head then it will not hold
enough warmth and humidity for a lice population to survive. Please do not do this to treat a
girl and if you use it for a boy but do not cut hair short enough lice will survive.
For further questions please contact your school nurse.
Thanks,
Kay Stein RN