head lice
definition
The head louse is a gray to light brown insect that belongs to the human lice family (Pediculidae). In the case of head lice infestation (pediculosis), the head louse nests in the human scalp hair and feeds on blood there.
Properties of head lice
The head louse can be 2.5-3.5 mm long and can therefore be seen with the naked eye. A temperature of around 28 ° C offers the head louse optimal conditions for survival, so that the hairy scalp represents a suitable habitat. The head louse sticks into the human skin with its appendage on the head and feeds on the blood drawn according to the principle of a capillary. The head louse secretes saliva, which stops the blood from clotting and thus keeps the blood fluid.
Multiplication of the head louse
The head louse is able to up to 10 eggs (nits) per day to discard. The eggs are only placed on the hair follicle and above all in the Neck and back ear region.
This guarantees the hatching larvae a safe source of nutrition, since the blood is particularly easy to reach at these points.
The larva hatches from the nit after about 7-10 days (nymph).
This larva needs an additional 10 days until it is sexually mature and thus continues the reproduction cycle.
Here it is important for the larva to be close to a rapid source of blood, because without blood the larva dies after one to two hours.
With a total of 14 to 21 days the head louse multiplies very quickly. A male head louse lives for around 15 days. Unlike these, the survival time of a female head louse is about a month, provided that she gets blood every 2 to 3 hours.
transmission
Head lice infestation is generally and most often caused by a direct contact with the affected scalp caused. Situations that allow such closer contact increase this likelihood. Especially Children in schools and kindergartens are affected by it.
A indirect transmission is indeed not that often to be found, but also not to be ruled out completely. This mainly includes items like Pillows or brushesthat catch the affected hair. However, since the head louse does not find a source of food here, it dies quickly and offers no ongoing risk of infection.
Generally it is also known that the head louse not about pets is transmitted.
Sometimes diseases can also be transmitted with the head louse, such as Typhus or five-day fever or Tularemia. What is important is that Accompanying symptoms parallel to head lice infestation pay attention and consult a doctor. However, unlike in developing countries, diseases that are transmitted by head lice are very rare in Europe to be found.
Occurrence
The assumption that the head lice infestation is caused by the lack of hygiene is a mistake, because the head louse found in washed and unwashed hair.
Anyone can be affected by a head louse infestation. In general it can be said that the head louse more often in children occurs than in adults, as this is related to the age-specific behavior in schools and kindergartens, which facilitates head lice transmission.
It was found that especially in summer Children are affected by head lice infestation. This is explained by the fact that summer holidays are spent in holiday homes, for example, where the close coexistence of different children makes head-to-head transmission easier.
Diagnosis of head lice
Is a noticeable scratching of the scalp determine, the possibility of a head lice infestation should be considered and examined immediately. The head lice infestation can be determine directly and indirectly.
As a direct diagnosis try to find the head louse in your hair.
However, this turns out to be difficult because the head louse moves quickly and hides in light.
However, one method would be that Wash hair with a shampooin which the lice cannot move. The hair will be in Strands combed with a special combbeing wiped on a white cloth. The head louse can be recognized on a white background as soon as it is present.
Head lice infestation is indirectly caused by the Finding nits, i.e. head louse eggs, detected. A magnifying glass can help. Nits are characterized by the fact that they stick to the hair root on the hair shaft and cannot be removed. you have one scale-like brown shape. If you find nits more than 1 cm away from the scalp, the nits are already empty or dead. However, it indicates head lice infestation some time ago.
Symptoms
Head lice infestation usually takes place asymptomatic and is not always necessarily recognized or established.
Characteristic however one is different pronounced itching, especially in the rear ear and neck region, which is usually an indication of the head lice infestation.
It comes about as Immune response on the saliva and excretions of the head louse.
The itching may be accompanied by small reddish dots in the same region.
Itchy skin can scratch too Inflammation these bodies lead. Sticky nits with a high infestation can matt the hair.
therapy
An effective therapy for head lice infestation consists of several aspects. It should not just one of the therapy options because head lice infestation can be effectively and effectively combated by applying several therapies and its recurrence can be reduced.
Chemical therapy
The chemical therapy provides for the head louse with Insecticides, the Pediculocidesto fight that in pharmacies are.
It is recommended that one General practitioner or pediatrician consulted if head lice are suspected who can then prescribe appropriate funds, especially when it comes to infants or toddlers. The chemical substances are there in different forms: shampoo, spray or gel. That matters exact dosage the means if you want to achieve effective control. Generally one is enough one-time insecticide applicationto reduce the risk of infection.
However, to ensure it is immediately recommended repeat this treatment after 8 to 10 daysto fight any head lice that may have hatched.
Pregnant women or nursing mothers should be particularly concerned about one suitable means inform, because with the frequently used agent Permithrin it cannot be ruled out that it can have a harmful effect on the child / embryo.
Mechanical therapy
In parallel with the chemical application, the mechanical therapy are executed. With a special nit comb should the affected hair intensely repeatedly wet combed become. It is important for the comb that the tine spacing is around 0.3mm so that the smaller nits or larvae can also be combed out.
It should at least four times within two weeks be combed out. However, more frequent use does no harm either. On the fifth day, the hair should be combed out again while wet to ensure that any hatched head lice have been removed from the hair.
After about two weeks, the wet combed can be checked again. If head lice infestation is still found after this time, it may be due to the resistance of the head louse to insecticides, or to a different dosage and imprecise distribution of the substance in the hair. Too short an exposure time for the preparations or the forgotten repeat treatment also lead to a returning head lice infestation.
Active ingredients
Medicines tested by authorities to control head lice are mainly based on the effects of the Pyrethrum extract from chrysanthemum flowers.
The action of this extract makes that Head louse nervous system attacked. This makes the head louse immobile and ensures that the insect is so badly damaged that it dies during the exposure time. Side effects of this insecticide are reduced by its light and oxygen sensitivity. In this way, substance residues in the hair are quickly eliminated from the hair, so that there are no consequences for the hair or scalp.
Mixed preparations from the extract with additivesact like alcohol also on the nits and let them die.
However, since these therapies are generally not specialized in nits and therefore do not kill them effectively, the second treatment, which has already been mentioned, is of enormous importance.
Besides these natural products, there are also synthetically manufactured substances. she often serve a long-term effect and aim less at nits than at live larvae and lice that hatch from their nits a few days later. With the variety of drugs and medical products on the market, you should find out about the correct and, above all, tested remedy from your doctor or pharmacy.
Follow-up care and prophylaxis
If someone in a household is affected by head lice infestation, it is recommended as a preventive measure from an infestation of the members living in the household and other contact persons, e.g. in kindergarten, to inform and investigate.
It is also suggested here prophylactic head lice therapy perform.
The Cleaning of brushes and combs for those affectedn makes sense to avoid even minimal risks of infection. It makes sense for each family member to have their own brush and comb.
In principle it is sufficient that the Vacuum apartment thoroughly. However, a complete sterile basic cleaning is not necessary.
Hair-catching fabrics such as pillows and stuffed animals can washed at 60 °, frozen or left for a few days become. Any head lice trapped in it will die and there is no longer any risk of infestation.
A prevention in public facilities is established by law. This means that the community facility, especially schools and kindergartens, should be informed immediately in the event of a head lice infestation. These then report this to the Health department. This may sound daunting, but it has no negative consequences and don't have to worry. The person concerned should avoid public facilities while they are contagious.
For this time there is no certificate required. Since there is actually no longer any risk of infection after the first treatment, it is sufficient for school, for example, to write a parental apology. After the treatment, school life can be resumed. This also applies to all other institutions. General prophylaxis should take place through an expansion of information in the form of parents' evenings or flyers in order to increase awareness of the detection and treatment of head lice infestation. This also applies to the perception and participation in such offers.
Further topics from this area
Pubic lice
The pubic louse particularly likes to settle in the hairy pubic area. The pubic lice infestation mainly leads to severe itching in those affected.
Here you get to the topic: Pubic lice
