Detecting and treating head lice

Head lice: brief overview

  • Appearance: up to 3 millimeters in size, flat, color translucent-whitish, gray or brownish; the eggs (nits) are up to 0.8 millimeters in size, oval, initially translucent, later white.
  • Transmission: mostly directly from person to person in close body contact; more rarely indirectly via objects such as hairbrushes or caps; NO transmission via pets!
  • Preferred localizations: on the head in the temple area, behind the ears, on the back of the neck and on the back of the head.
  • Treatment: Best combination therapy of wet combing out (with lice comb and possibly magnifying glass) and insecticide application.

How to recognize head lice

The eggs are oval, about 0.8 millimeters long and protected by a chitinous shell (nit). Initially, the nits are translucent, later (when the larva has hatched) white. They stick to the hair near the scalp.

Often, a head lice infestation is discovered by chance, for example, when a few of the parasites fall out of the hair while combing. Therefore, the diagnosis is very rarely made by a doctor, but mostly by the parents or occasionally by educators/teachers.

Often there is already a suspicion that someone has head lice – either because of the symptoms or because there are already known cases of louse infestation in the immediate vicinity. Then the head can be systematically searched for the animals. Tools such as a magnifying glass and a lice comb are advisable for this.

Then you should carefully comb through all the hair with the lice comb, its tines touching the scalp with each stroke. The head lice as well as their eggs (nits), which adhere to the hair close to the scalp, get stuck between the very closely spaced tines (spacing: 0.2 to 0.3 mm). This allows them to be combed out and identified more easily. To do this, it is best to wipe the comb on a piece of kitchen or toilet paper after each stroke and then wash it.

A magnifying glass is particularly good for detecting young head lice that are still in the nymph stage. They are easily overlooked with the naked eye. In addition, the magnifying glass helps to distinguish head lice and their eggs (nits) from dandruff.

Head lice: treatment

Wet combing out

This method of head lice treatment is complex and requires a lot of patience from the person being treated and the “handler”. This is often difficult, especially with children. In addition, combing out head lice alone often does not completely eliminate them. Therefore, it is better to combine mechanical therapy with locally applicable remedies against head lice.

Remedies against head lice

  • None of the head lice remedies works 100 percent. Each must therefore be applied several times.
  • The agents may temporarily irritate the skin and cause itching.
  • Agents in spray form could be inhaled and then possibly cause allergic reactions. They are therefore not suitable for children with respiratory diseases such as asthma (solutions or gels against head lice should be preferred here).

Insecticides

The insecticides against head lice must be applied several times (usually after seven to ten days) to bring success. The exact application depends on the product. Before starting treatment, read the instructions for use and adhere to them, especially with regard to the exposure time and duration of application of the agents. Otherwise, it may happen that some head lice or larvae and eggs survive.

Silicone oil

Insecticides have been used against head lice for decades, including in other European countries. As a result, head lice have developed resistance (resistance) to some insecticides. Therefore, agents with silicone oil (dimeticone) are now used, which are without insecticide and therefore do not cause problems with resistance.

Special attention should also be paid to the warning labels: Silicone-containing agents are highly flammable. After application, the child should therefore not be near naked flames and should also not use a hair dryer!

Dimethicone is considered non-toxic and is not absorbed into the body through the skin.

Vegetable oils

Recommended: Comb combing out and insecticide!

Experts recommend combining combing out with the application of an insecticide against head lice. This is said to show the best success rate in head lice treatment. The prerequisite for this is that the insecticide is used correctly according to the instructions for use and the lice comb. If you are unsure, it is best to seek advice at the pharmacy or from your doctor.

The following treatment regimen is recommended:

Day

Measures

Day 1

Day 5

Wet comb out hair to remove early hatched larvae.

Day 8, 9 or 10

Treat hair again with insecticide to kill late-hatched larvae.

Day 13

Control examination by wet combing out.

Day 17

Possible final check-up by wet combing out.

Research: the plasma lice comb

Home remedies against head lice

Those who are concerned about the potential side effects of insecticides or silicone oil like to turn to alternative treatments for head lice. Home remedies such as essential oils (for example, tea tree or lavender oil) and vinegar are said to be able to effectively combat the parasites.

With vinegar, the effectiveness against head lice is also unproven. In any case, it is recommended to leave the vinegar on for half an hour after applying it to the hair and then wash it out.

Other home remedies against head lice include alcohol, aloe vera and caustic soda. Here, too, the effectiveness has not been proven. The same applies to sauna visits, which are sometimes recommended against head lice infestations.

Does the rest of the family also need to be treated?

If a child has head lice, all members of the family should be examined for the parasites, preferably by wet combing. Only those who are also infected should also be treated.

Head lice: causes and risk factors

This almost always happens through direct transmission of head lice from person to person, for example when children put their heads together while playing. The parasites then migrate from hair to hair – they cannot jump.

By the way, contrary to popular belief, pets are not carriers of head lice!

Where do head lice prefer to sit?

Head lice particularly like to cavort on the temples, behind the ears, on the back of the neck and on the back of the head. Here the skin is very thin and has the optimal temperature for the little bloodsuckers.

Occasionally, head lice are also called hair lice, although this term is misleading and, strictly speaking, incorrect, since ultimately all human lice are “hair lice” (including, for example, crabs).

How do head lice feed and reproduce?

The ever-available food supply allows head lice to reproduce industriously: The females can produce 90 to 140 eggs during their approximately four-week lifespan. About 17 to 22 days after fertilization, they lay the eggs: they attach them to the hair near the scalp with a special secretion. This “glue” is insoluble in water, so the eggs do not come off during normal hair washing.

Why do head lice mostly infest children?

Infestations of head lice are most common in children between the ages of three and twelve. The reason is that they have more close physical contact than adults during everyday play and romping. This makes it very easy for the lice to change hosts. Adults rarely become infected, and when they do, it is usually with their children who bring head lice home from school or other community settings.

Head lice: symptoms

Frequent scratching of the head can leave scratch marks that may even bleed. This skin damage can easily become inflamed, which can lead to an eczema-like rash (“lice eczema”). In addition, bacteria can easily colonize the damaged scalp. This bacterial superinfection can cause the lymph nodes on the head and neck to swell.

Due to the itching, affected persons often sleep very restlessly.

Head lice: mandatory reporting

To be fair, parents should also inform anyone with whom the child has close contact about the head lice infestation. This could be playmates (or their parents) or members of the child’s sports club, for example.

Head lice: Prognosis

Head lice are annoying, but harmless. In our latitudes they cannot transmit any diseases. If treatment is carried out correctly and consistently, head lice are quickly gotten rid of.

Prevent head lice

It is difficult to prevent head lice because they spread so easily. However, if an infestation is known to exist in the immediate environment (family, community facility, sports club, playmates, etc.), one should avoid physical contact with the person in question if possible and not share caps, scarves, combs, brushes, etc.

A “preventive” head lice treatment of all family members when someone is infected is not generally recommended.