Head Lice - the facts
“What is the best way to get rid of nits?”
“What is the best cure for head lice?”
“What helps quickly against head lice?”
Here you will find the answers from the head lice specialists of the Dutch Lice Clinics:
The reason why treatment often fails is that an infection contains an average of 100 times as many nits as lice, and especially these nits are so difficult to get rid of.
Lice treatments rarely kill all nits, and the regular nit comb rarely removes all nits.
As a head lice home treatment, there simply is no quick fix.
You can read below what works and what doesn't, and how it's still possible to get rid of any head lice infection, at home.
In general, there are 3 ways to treat head lice:
- Remove with a nit comb
- Kill with a lice treatment
- Professional dehydration method
Remove with a nit comb
As also the R.I.V.M. (Dutch National Institute for Public Health and the Environment) states with her "Louse in your hair? Comb your hair!" - Campaign, it is proven more effective to comb than to use lice remedies.
But even combing with a regular nit comb is only successful in 38% to 57% of cases after a fortnight.
This is because nits and nymphs often slip through the comb teeth and lice flee away from the comb.
It is therefore important to at least use a nit comb with metal teeth.
But even metal teeth often get pushed apart by the hair passing through, so that the nits still slip through.
It is the ‘Licemeister nit comb’ that is used by many head lice professionals, of which the teeth are inserted through a unique sealing technique, each tooth enclosed all the way around and deeply in the handle, which prevents the comb teeth from getting pressed apart.
This makes sure the nits are effectively combed out.
Information and instructions for an effective combing method that guarantees that the entire head lice cycle is eliminated in just 4 to 7 comb treatments, can be found here:
Professional Combing Method.
Kill with a lice treatment
There are commercial- and home remedies.
Unless resistance has developed, all lice remedies are generally effective against lice, but regardless of brand or type, they have limited effect against nits (lice eggs).
All health authorities state that lice remedies are only effective in combination with combing with a nit comb.
Since a significant part of the nits often survive lice treatments, new lice hatch within ten days.
Still, lice remedies often promise to kill nits. If research shows that treatment has killed a (small) part of the nits, the manufacturer can claim: "kills nits". However, it is not obliged to communicate that only a (small?) part was killed.
Lice-killing treatments can be roughly divided into 3 groups:
- Pesticides as an active ingredient
- Dimethicone as an active ingredient
- Home remedies
Pesticides, like permethrin, are the least effective. Lice are increasingly resistant to these agents so that lice are not killed. Permethrin is a neurotoxin. There is much debate about its health safety.
Dimethicone is a chemical silicone oil that clogs the louse's breathing holes and causes the louse to suffocate in its own body fluid. Resistance is not possible. No known health risk. However, it does suffocate the scalp and hair, possibly leading to dry skin, dandruff, and itching.
Dimethicon, like any other home-treatments, does not guarantee that it will kill all nits.
Home remedies are often used because someone happens to be successful with them, and since they are mostly natural, inexpensive, non-commercial products, people like to stick to them.
Vinegar, green soap, mayonnaise, eucalyptus oil, tea tree oil, rosemary oil, baby hair lotion, hair dye, alcohol or even the dangerous varieties such as petroleum, turpentine or even animal flea products!
Unfortunately, we have to disprove all of these myths.
All of these home remedies only work (to a certain extent) against lice, but hardly, if at all, against the eggs.
The lice are the tip of the iceberg, the eggs form the largest part of the iceberg, which is invisible below the water surface.
It is also not true that a natural remedy cannot have any side effects. Even an essential oil like Tea Tree can have a hormonal side effect in some cases.
Why do other people succeed with lice treatments and I don’t?
Because every case is different.
Someone with only 40 nits has a higher chance of success than someone with 40,000 nits.
An infection in short or thin hair develops less quickly because the humidity and temperature in it are too low for the nits to develop effectively.
Someone who does not experience the typical lice-itch, doesn’t get alarmed, and won’t notice the infection until there are already dozens/hundreds lice and thousands nits.
For example: a short haired boy who has been infected for merely 3 days, is most likely more successful with a lice remedy than a thick haired girl who has been infected for 6 weeks.
Are lice remedies the cause of chronic / long-term infections?
(Commercial) lice remedies are by far the most widely used treatments.
However, since lice remedies promise to kill the nits, which can give the impression of killing “all” nits, many people do not realize that the infection has not been resolved, when only a part is actually killed.
In our lice clinics we keep hearing from people that they have not combed or have not combed long enough because they wrongly thought that the lice remedy had (completely) worked.
Often, they then start using countless other brands with the same result without using an effective 2-week combing treatment.
By that time, the amount of (viable) nits has accumulated so far, that it has become impossible to resolve the infestation without professional help.
The number of people that are infected by the people with long-term infections is so big, that the probability of recontamination is also considerable.
Professional dehydration method
The AirAllé device, which is exclusively used in professional Lice Clinics, with which the nits are guaranteed to be killed, using a dehydration method, has been in existence since 2009. This medical device treats the hair and scalp where the lice and nits are located and ensures that the embryos in the eggs and the lice are completely dried out.
The leading Lice Clinics of America and the Lice Clinic in the Netherlands only use this device where certified head lice specialists, that help you to get rid of infections within 90 minutes regardless of their severity or duration.
The great thing is that it is a physical treatment that does not use toxins like pesticides. Safe and therefore no resistance. You can find information on this treatment method here: Lice Clinic
ATTENTION: It is not possible to kill lice or nits effectively or safely with a hair dryer!
A hair dryer is made to dry hair. However, nits are close to the skin. To dry a nit to death, it should be treated with a certain and accurate air temperature and -flow for 30 seconds, and the air should not be blocked by hair. This is only possible with the patented AirAllé device.
What is a louse?
A head louse is a parasite that lives exclusively on humans. A human head louse cannot survive on an animal, so you cannot get or give head lice by contact with animals.
An adult louse is about the size of a sesame and has a brown-gray color.
Lice have a flat body with 6 legs and 2 antennas. Lice breathe through small air holes in their bodies, called trachea. They can close them to hold their breath for up to 8 hours.
A louse drinks blood from its host on average five times a day. Lice cannot walk, fly or jump. They only climb from hair to hair.
What is a nymph?
The lice right after hatching are called nymphs. At first they are as small as a nit. With the naked eye they resemble a moving dust particle.
Lice have an exoskeleton (outer skeleton), just like a crab or a lobster.
The hard exterior and growing interior ensure that the growing nymph sheds three times before it reaches adulthood. If a nymph has recently lost its exoskeleton, it is almost transparent, so you can see the drunk blood, and therefor the nymph looks red.
Nymphs usually lie flat on the scalp. When combing, nymphs are often missed because they slip through the tapered tips of the comb teeth.
This problem can be solved by combing with the specially developed 'Luizenkliniek comb cream', in which the nymphs stick and are combed out with this cream and all.
What is a nit?
The eggs of the head lice are called nits.
A female head louse can lay between 100-150 eggs in only two weeks time.
Nits are glued to the hair very close to the scalp and can stay firmly glued for months, up to a year, even if the egg has hatched or if the embryo in the egg has died.
Fortunately, not all eggs hatch, which is why she lays so many eggs, to make sure the infection continues.
Brown and white nits? Dirt and dandruff?
A nit is a transparent egg that contains an "unborn" louse: the embryo is brown of color, which makes the nit appear brown.
The egg hatches after 7 to 10 days. The empty transparent shell that remains appears white because of the colored background of the hair.
So white nits are empty eggs, brown nits are eggs with a (possibly living) embryo in them.
Dirt is often confused with viable nits.
Dirt is loose in the hair, brown nits are attached to the hair. So strong, that you need your nails to pull them off.
Dandruff is often mistaken for empty nits.
Dry scales are loose, white nits are attached to the hair.
People with dandruff and an oily scalp often have a type of dandruff that sticks to the hair as little balls, due to the tallow, which makes it look like white nits.
There is even a kind of dandruff that is attached to the hair shaft like a cylinder. Since this type of dandruff is very similar to white nits, it is also called pseudo-nits (see photo 4 below).
How can I tell if a nit is viable?
A nit can be viable if it meets all of the following criteria:
- The nit is maximum 1 cm away from the scalp
- The nit is firmly attached to the hair
- The nit has a light- to dark brown color
White is empty!
Half full (shriveled) is dead!
1 cm. or further away from the scalp is dead!
Head lice means itching. Or not?
What causes the itching of head lice?
When a head louse drinks blood, it applies part of its saliva to the wound, making the blood clot less quickly.
It is this saliva that causes the itching, provided you are allergic to it.
Around 53% of people are not allergic to lice saliva and have no itching at all, even if they have hundreds or thousands of lice.
The lice running around is imperceptible, so it is not the cause of itching.
The itching is very similar to the sensation that is caused by an insect that crawls over the skin, and so, often people are falsely convinced that lice are (still) around.
A professional head lice screening to rule out head lice, such as with the ‘Head Lice Kit’, and/or the itch relieving product ‘Scalp Tonic’, will resolve these symptoms in most cases.
If someone still itches afterwards and cannot convince themselves of the negative result of the professional screening, the cause can only lie in the corner of psychological itching or Delusional Parasitosis.
By definition, does itching mean that I have head lice?
No. Itching can have many causes. Weather changes, psychological itching, dry scalp, reactions to hair care products and even lice remedies can cause itching because they are not always mild on the scalp.
Also, there is an incubation period for the itching sensation. Itching can take 2 weeks after infection to develop, and itching can persist for 2 weeks after the infection is cleared.
Do I have a self-sustaining itch?
Many people with long-term head lice infection, or if getting head lice has been a traumatic happening, experience chronic itching.
It has been scientifically proven that the brain emits more itching signals if you have had head lice for a long time or for whom it was traumatic.
Every small stimulation (or even no stimulation) can cause an itchy signal that is (un) consciously associated with head lice, therefor creating a vicious circle.
People with long-lasting itching symptoms who are convinced that they are caused by lice (or other parasites) without actually having lice suffer from what is known as ‘Delusional Parasitosis’ or Ekbom Syndrome.
How does one get head lice?
How do head lice spread?
They only do so through hair-to-hair contact.
Lice have climbing legs, no walking legs. They climb from hair to hair and will never let go of the hair. Lice do not spread through objects unless these objects contain hair such as hairbrushes or hair ties.
Head lice are genetically programmed to spread.
If an opportunity comes along to colonize a new host, they won't resist.
An adult female louse only needs to mate once.
She stores the sperm in her body and can lay eggs every day. Fertilized females in particular are very keen to travel and are always on the look out for a new host to lay her eggs.
So, it only takes one fertilized female who ends up in your hair, to get infected.
Basically, a louse does not spread through swimming water. A louse can hold its breath for up to 8 hours, so it does not have to leave a head that is under water to prevent suffocation.
A louse cannot swim either. In the rare event that a head louse detaches from the hair, it is very capable of floating and could end up into someone else's hair, due to the movement of the water, but this chance is extremely slim.
How quickly can contamination occur?
Lice climb from hair to hair with six legs and strong claws. They can reach speeds of up to 30 cm per minute.
A quick hug, a swift kiss on the cheek, a group selfie or a look at the other person's screen, on which their hair contact is made, is sufficient.
People are highly unaware how often a day their hair touches someone else’s hair unnoticeably. If a louse is holding on to the hair that comes in contact with the other persons hair, transition is done in a matter of seconds!
Who can get head lice?
Everyone. No matter whether you are male, female, young or old. Lice only need a warm scalp. People who radiate a lot of heat or have a lot or thick (insulating) hair can be more prone to head lice.
The reason men/boys are less likely to have head lice is because they usually have short hair, which makes it too cold for head lice. You can get them though, even one mm of hair is enough for head lice to hold on and stick their nits on.
But Afro hair doesn't get head lice, does it?
Yes it can! A louse just needs a warm scalp, blood to drink and hairs to grab. So every living human with hair can contract lice.
However, the claws of lice are adjusted to the hairtype that it is used to live in.
Since the shape of Afro-, Asian- or Kaukasian hair are different, they tend to prefer the hairtype they are accustomed to.
But once in the new haartype, they adjust pretty well, and develope an infestation quickly.
Can I get infected by coats, hats and clothing?
No. A head louse cannot move well on normal surfaces or textiles.
A head louse needs hair to move.
In addition, a louse needs constant warmth and moisture that evaporates from your scalp. The louse must also be able to drink blood 5 times a day.
Without these 3 elements, a head louse cannot survive for more than 48 hours, but before that time it has become too weak to reproduce.
A louse therefore has absolutely nothing to look for in an object and will certainly not risk finding a new host through an object.
Lice always hold on firmly to the hair and only move to another host by stepping over from hair to hair, never intentionally from hair to object to hair. Getting on an object unintentionally rarely happens to a healthy viable louse. Only weakened or old lice can loose grip of the hair, but they can't cause an infection either.
However, there are 3 objects that are an exception to the rule:
- Hairbrushes. When brushing, hair with lice attached to it, can end up in the brush. A louse shuns light and can go into the small openings of regular hairbrushes.
- Hair ties. Hair with lice on them can get on and in the ties when pulled out.
- Fur. Fur is not only cruel, but also consists of real hair, so that a louse can mistake the fur collar for its host. A louse can easily and quickly move in or to the next fur collar or head.
What can I do to stay lice-free?
- Wear the hair in a bun! Loose hair, long tails or braids come into contact with someone else's hair more easily, which can cause lice to step over.
A louse is very flat and can easily squeeze between the tied hair of a braid or tail.
- Use one-piece plastic brushes, like the Tangle Teezer, and hair ties ,like the Invisibobble rubber bands, that are freed of hair. When hair-free, lice cannot stay behind in them.
- Don't wear real fur!
- Use the professional ‘Lice Clinic Combing Method’ every week, only for 5-10 minutes at a time. If you do this, every week you will know for sure that you are free of lice.
If you do find a louse, that louse hasn't had more than a week to spread and multiply.
Because you detect it so quickly, the infection can be easily removed with just one combing session.
The shorter the infestation, the fewer people around you who have been infected, the less likely it is that treatment will be undone by recontamination.
Life cycle of Head Lice