Headlice are wingless insects about 1/8 to1/4  inch long, or the size of sesame seeds, and they have 6 legs containing claws to grip the hairshaft.  They cannot hop, fly, or jump.  They must have human blood in order to survive, and they cannot thrive on pets. They live about 30 days on a human and will starve to death in 2-3 days if not on a human.  A female louse may lay 100 eggs in her lifetime.  Nits (louse eggs) are easier to see than lice, and can usually be found behind the ears or at the neckline.  Nits are yellowish-white to tan, smooth, oval shaped structures smaller than sesame seeds and are attached at an angle to the side of the hairshaft.  Nits must be laid by live lice.  Lice lay their eggs about 1/4 inch from the scalp.  Nits do not spread from person to person because they cannot move.  It takes 6-7 days for a nit to hatch after it is laid, at which time the nit is about 1/2 inch from the scalp. 











The newly hatched lice (called "nymphs") molt three times in eight or nine days before becoming adults.  During this time, the nymphs, as well as the adults, feed with piercing and sucking mouthparts, injecting saliva to keep blood from clotting.  In another 7-10 days, the female matures and begins laying eggs.  When they hatch, lice are clear in color.  After they begin eating, they become reddish-brown in color, then become grey, brown, or black, tending to assume the hair color of the host.  The discovery of nits always confirms infestation with headlice.  Lice are not a health hazard, they do not spread diseases, and their presence is not a sign of uncleanliness.  It is not a disgrace to get headlice because they are not selective who they infest.




Headlice can be acquired by anyone and are spread by personal contact or by touching any surface or item that has been in contact with an infested person, including bedding, hats, combs, etc.



Generally, the first symptom of head lice is persistent itching or scratching at the back of the head or around the ears. The lice like to stay close to the head where it is warm and close to their food source, human blood. Repeated scratching of his or her head may be a sign that the child has headlice.



If a child is observed repeatedly scratching his or her head, check the hair shafts and scalp closely for head lice or their nits (eggs). It is important to check for head lice in good daylight and with a magnifying glass, if needed.
Headlice
Headlice
Description and biology
How lice are spread
Symptoms
Detection
Treatment
Headlice are becoming resistant to products currently available used to treat them.  This means that, even if used properly, the special medication may not be able to kill all the lice and nits.  As many as 30% may still live and keep the infestation going.

Not all products available are used the same way.  Some products are to be applied to dry hair while others are to be used after shampooing as usual and towel-drying the hair.  Different products are to remain on the hair different lengths of time.  Be sure to read and follow the directions that come with the product you purchase.

Clothing from the waist up should be removed during treatment because lice can be on the clothing and crawl back into the hair.  Clean clothing should be worn after treatment.  Be sure not to place the clothes you had on before treatment by the ones you will be putting on afterwards.

If the product you are using is to be applied to hair that has been shampooed and towel-dried, you must use a different clean towel after completing treatment.  The first towel may have live, untreated lice on it that can cause reinfestation.

Because some lice and nits can still be alive when treatment is finisned, it is extremely important to remove ALL the lice and nits from the hair.  Special fine-toothed combs called nit combs are most helpful in accomplishing this.  When the comb is full, it can be cleaned with an old toothbrush, fingernail brush, or unwaxed dental floss, and then be reused.  Nits can also be removed by grasping them between the fingernails and pulling them from the individual hair shaft.

To use the nit comb, first divide the hair in sections and fasten off the hair that is not being worked on.  Using the comb, go through the section from the scalp to the end of the hair.  Dip the comb into a cup of water or use a paper towel to remove any lice, nits, or debris from the comb between passings.  Go on to the next section until all sections are completed.  Even under the best of conditions, a few lice or nits may be missed.  Use the comb to screen the infested person every day and regularly thereafter.  Be sure to remove all nits immediately.  Being consistent and diligent about screening and manual removal will go a long way toward controlling the problem.

Since lice glue their eggs to the hair shaft, the nits will not wash out of the hair.  Over-the-counter products have become available to help make removal easier.  Some people have found that rinsing the hair with a vinegar solution helps loosen the nits.  Another possibility is applying a conditioner to the hair and combing out the nits before the conditioner is rinsed out.  Although these products may help loosen the nits, they will not remove them.  Manual removal through extensive combing remains the only way to rid the head of nits that have the potential of hatching and continuing the problem.  There are no short cuts.  There are no "quick fixes".

It is very unlikely that only one person in the household has lice.  Everyone sits on the same furniture and rides in the same vehicles.  More than one person may lie on a bed.  Toys are shared.  Lice crawl across these things into the heads of others.  For this reason it is necessary to check the heads of everyone in the household for lice and nits.  If you see only the eggs but no lice, that person is infested.  Realize that for eggs to be there, a louse was there to lay them and the eggs will hatch.  All infested persons should be treated at the same time.

All washable clothing, caps, hats, towels, bedding, pillows, and stuffed toys that have been in contact with each infested individual should be washed in hot water and dried in a hot dryer or ironed.  Use bleach when possible.  If clothing is not washable, it should be dry-cleaned.  Soak or wash other toys in hot, soapy water that contains bleach.  Toys, clothing, and bedding that cannot be washed or dry-cleaned should be sealed tightly in a plastic bag for 14 days.

Combs, brushes, and hair ornaments should be soaked for one hour in either bleach solution or in a 2% Lysol solution.

The environment must be treated to eliminate lice that are there.  All furniture, mattresses, floors, and vehicles must be vacuumed thoroughly.  Move the furniture and vacuum under it.  Remove the cushions from the couches and chairs and vacuum.  Sprays are available to purchase to help with killing the lice, but keep in mind that lice are becoming resistant to these products.  So the vacuuming itself is the critical process.  Empty or change your vacuum bag when finished to prevent lice from crawling out of the machine.
Prevention
Teach everyone in the house to never share combs, brushes, hair ornaments, caps, hats, bicycle helmets, etc.  Everyone should have and use their own.
Scalp showing results of scratching due to headlice.  Notice the white colored nits in the top left of the picture.
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