Lice, the 20 tips to know and fight them

Fonte: shutterstock

Children and head lice

They haunt the heads of children and seem resistant to any attempt to prevent their unwelcome arrival: they are head lice, now ubiquitous in schools and communities such as nurseries and gyms. Here are the 20 tips to get to know them and fight them with the help of the Milanese dermatologist Marcello Monti.


10 myths about head lice

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Not even these nasty parasites are saved from fake news: false beliefs about the conditions that favor or hinder them and about their real danger. Let's debunk the most ...

Read also: head lice in children, the guide

1. The louse is an obligate parasite: it does not survive for long except on a human being.

The species that infests the hair of children (and adults) is not even able to survive on animals: it needs humans, whose blood it feeds on by pricking the scalp.

2. The itch caused by lice is not due, as popular belief suggests, to dirt, but to the insect bites.

We must dispel the myth that lice infest people with poor personal hygiene. Indeed, the cleaner the hair, the easier it is for lice to be able to 'take root' and deposit their eggs at the root of the same.

3. The life cycle of the louse occurs through three stages and lasts about a month.

It starts from the egg (also called nit) which hatching gives rise to the nymphs, immature forms of the adult parasite. The nymph is very small and reddish, while the adult louse is dark and 2-4 mm long. The adult louse lays the eggs which in turn hatch after 8-10 days reproducing the cycle.

4. Head lice do not transmit infectious diseases.

Certainly, if they are numerous, they can induce scratching lesions which in turn can become infected. In some cases, allergic reactions may also appear.

5. The parasite survives about a month on a person's head but no more than 48 hours on objects and in the environment.

Eggs can survive longer away from the scalp but are unable to mature and hatch if they are not kept at a temperature similar to that of human skin. This means that the parasite is very unlikely to get to a child's head by passing through the environment. [See what to do if your child has lice now]

6. Head lice lay their eggs at the root of the hair and in particular on the nape of the neck, behind the ears and sometimes at the root of the fringe.

It is often difficult to see the adult insect, unless the infestation is already advanced: instead the eggs are very numerous, which have a translucent white or, at times, dark brown appearance and are tightly attached to the base of the hair.

See also: head lice pictures, here's how to recognize them


Head lice photos: how to recognize them

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Lice are small insects that infest the scalp of adults but especially of children and seem resistant to any attempt to prevent their arrival. How...

7. Louse eggs can be confused with dandruff.

To understand the difference just try to eliminate them from the hair with a little shake. The dandruff will fall off while the louse egg will remain firmly glued to the stem.

8. A warning sign for parents is certainly itching.

Every time the child scratches his head, it is necessary to check for lice.

9. Another symptom that requires careful monitoring is the presence of redness and scratches from scratching in the most infested points.

The most infested points, as we have seen, are the nape of the neck and the hairline behind the ears.

10. Good natural light is required to examine the hair and discover the intruder.

It is best to carry out the check during the day, in front of a window. Sometimes the electric light makes the eggs transparent, especially if you are in front of a blond hair (the most difficult to examine).

11. It is good to have a magnifying glass, a fine-toothed comb (available at a pharmacy) and a sheet of white paper.

Just pass the comb through your hair to see the adult louse fall on the sheet. However, adult insects are not always present in sufficient numbers: it is therefore necessary to look for the eggs with the magnifying glass and separate the hair into four areas, held with clips or hairpins, then proceeding to a systematic examination strand by strand.

[Also read the 6 tips for removing nits and lice treatment]

12. The only effective form of prevention is the twice-weekly check of children's hair.

In case of infestation it is necessary to proceed immediately with an eradicating treatment and notify the child's class and the school management. In this way it is possible to limit the spread of parasites over time and space.

[Read also: All the lice remedies and a friend of my child has lice, can I prevent them?]

13. It is good to reiterate that there is no relationship between personal cleanliness and head louse parasitosis.

However, there are some individual characteristics (hair type, skin odor) that make some children get lice more frequently than others.

14. A problem that also makes prevention difficult is that of resistance to the most common pesticide products.

In many cases, the children treated are actually still infested and continue to spread the parasite without the knowledge of parents and teachers. The lack of effectiveness of the treatment may also depend on an incorrect use of the same or an inadequate shutter speed. It is important to follow the instructions for use of the chosen product to the letter not only to make the intervention effective but also to maintain its effectiveness in case of further infestations.

[Read also: how to get rid of lice and products on the market]

15. All children with head lice should be treated, as well as all cohabitants and peers they have had close contact with.

According to the guidelines of the British National Health Service, it is also useful to give prophylactic treatment to anyone who shares a bed with a person infested with lice, even if no parasites or nits are seen.

16. The treatment must be carried out simultaneously: if the child is treated immediately and the rest of the family 24 hours later, the whole process can be ineffective.

In general, a second treatment after a week is always recommended because no product is 100% oocidal, that is, it is possible that some eggs survive and generate viable lice.

17. If there are few eggs on the head and a lot of patience, it is possible to avoid the insecticide treatment by cutting the individual hairs on which an egg is found at the base with a scissors.

The cut hair must be carefully collected in a bag which is then closed and eliminated. To facilitate the elimination of eggs after treatment with insecticide, it is useful to rinse with water and vinegar: the latter dissolves the sticky substances that the louse produces to anchor the nit to the hair.

18. It is not enough to treat the person: it is necessary to remove any eggs from clothing and furnishings that came into contact with the head in the 48 hours prior to the discovery of lice.

It is good to collect hats, scarves, sweaters, pillow cases, sheets, blankets, sofa covers and towels and wash them in the washing machine at 60 ° C. Louse eggs are in fact killed by exposure to temperatures above 55 ° C for five minutes.

19. There are general indications for the treatment of lice, regardless of the type of product chosen.

There are 10 general rules to follow. Read which ones.

  1. Before applying the treatments, it is good to remove clothes that could get stained. 
  2. Apply the product strictly following the instructions written on the package. Pay particular attention to the shutter speed and rinsing methods.
  3. After the treatment it is advisable to wear clean clothes.
  4. If you see lice still alive but moving with difficulty 8-12 hours after treatment, a second treatment is not necessary: ​​some insecticides kill the parasite rather slowly.
  5. If after 8-12 hours the lice move at the same speed as before, it means that the product has not worked. It is necessary to repeat the treatment with a different substance.
  6. After the treatment, it is essential to mechanically eliminate the eggs with the special fine-toothed comb contained in the product packs or sold separately. A normal comb is not enough.
  7. Every day for about a week after the treatment it is necessary to check all the hair and remove any residual eggs with the comb. The eggs left on the comb should be collected with a paper handkerchief to be carefully thrown into the dustbin. The same procedure must also be carried out after the second treatment, to be carried out about a week after the first.
  8. It is absolutely contraindicated to mix different products in the same treatment.
  9. The rather high cost of lice products is a strong deterrent to their correct use. 
  10. The high costs often direct the consumer towards shampoos, which allow more people to be treated with a single package but which are less effective than other formulations. Unfortunately, anti-lice products are not considered drugs but medical-surgical aids and therefore are not reimbursable by the National Health System.

20. The removal of the nits is essential for the success of the treatment.

The 6 practical tips to optimize the procedure. Read here.

  1. Get a fine-toothed comb
  2.  Divide the wet hair into small sections
  3.  Pass the comb over the lock from the base of the hair to the tip with a single continuous gesture
  4.  Perform the same movement in the opposite direction, from the ends of the hair towards the base
  5.  Clean the comb with a tissue every time the gesture is repeated
  6.  Dry your hair with a hot hair dryer, because the parasite is sensitive to heat.

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Advice from Marcello Monti, head of the dermatology service of the Humanitas Institute of Rozzano.

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They infest the heads of children and seem resistant to any attempt to prevent their unwelcome arrival: they are head lice, now ubiquitous in schools and communities as kindergartens ...

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