Are lice dangerous to human health?

A louse bite causes an unpleasant, irritating itching and skin burning sensation. It hinders concentration of the mind and causes poorer results in learning. Continuous scratching of itching sites on the head is the cause of skin irritation and bacterial infections. The parasite’s saliva and feces may also cause an allergic reaction manifested as rash on the nape of the neck and head skin. Infestation with head lice has negative consequences also in personal and social aspects. It causes a strong stress in the infested individual and the awareness of negative perception of infestation with lice by the environment.

Do lice cause itching?

Head itching may be but does not have to be a symptom of lice infestation. What’s interesting, not everybody infested with lice will experience itching sensation. Head itching may have several causes:


  1. During skin puncture a louse introduces its saliva into the wound, which causes an annoying itching and burning sensation.
  2. The parasite’s saliva and feces may cause developing of allergic reaction, which increases skin burning sensation and itching. In individuals who are more sensitive and prone to allergy, a visible reddening may occur on the hair line and behind the ears.
  3. It happens that even a thought of the parasites causes itching and spontaneous head scratching.
How do head lice spread?
  1. Head lice live only on human’s heads.
  2. They cannot jump or fly.
  3. They are not carried over by pets.


The head lice spread by direct contact. To move from one head to another, the heads of two people must come into contact. Full of such opportunities are playgrounds, leisure activities, camping sites and summer camps. Kids can easily get infested with head lice at school where lice have a great opportunity to spread. Often, the infestation occurs through shared use of combs, brushes and hair elastics, and also thru using someone else’s pillows, towels, hats, scarves and other clothing.

How to check whether my child has lice?

The best way is a regular inspection and hair combing using fine-tooth comb. Attention should also be paid to the appearance of the scalp. Infestation with lice is accompanied with local redness of the head skin – particularly behind the ears and on the hair line. Small papules and discharge may also appear, which develop due to scratching of the itching skin. 

Can I protect my child against lice?

Yes, but some rules should be followed. Explain your child that it is not allowed to borrow hats, combs and hair bands from other children. The risk of infection is smaller if the hair is short, braided or tied in a ponytail. Check your child’s hair at least twice a week or even every day if head lice have been detected at school. Use a lice repellent – Nitolic prevent plus regularly to protect your child against the head lice infestation.

Can I acquire lice through contact with bed linen or towel?

It is worth to know that lice can survive without the host up to 48 hours. This means lice can easily get in contact with human head via contact with infested household items like bedding or towels. Therefore, it is extremely important to clean the house, wash all personal items including clothes, towels and bedding.

Can I only acquire lice at school or nursery school?

Lice spread thru direct head to head contact. Such contacts are most common at school. However, lice can be acquired everywhere and from everybody. Playgrounds, camps, and any crowded places like trams, buses or airplanes are great areas to get head lice.

Does hair wash removes lice?

No, it doesn’t. Simple hair washing isn’t going to eliminate head lice. They are resistant to water immersion and use of regular shampoo.

What to do when we become infested?

Start treatment immediately. In order to get best results, it is important to conduct the treatment simultaneously in all persons in the immediate environment, who might have come into contact with the parasites. Apartments should be thoroughly cleaned, since lice can survive off human scalp for even two days – on bed linen, blankets, clothing, upholstered  furniture. The items that cannot be washed should be tightly closed in plastic bags for several days, as nits can survive even up to two weeks off the host. Therefore, the places where hair of an infested person can be present, like carpets, armchairs, sofas and even car upholstery must be thoroughly vacuumed. All hair toiletries (brushes, combs, hair elastics, etc.) should be discarded and new ones should be bought.

How quick a person can be re-infested after effective elimination procedure?

It can happen immediately after. An effective delousing procedure does not mean acquiring resistance to another invasion of parasites. Finding live lice after the treatment means that procedure was ineffective. The causes may vary:


  1. Resistance of lice to the applied solution
  2. Application of insufficient amount of lice-eliminating solution. Such a situation can take place in case of long and thick hair. The procedure should be then repeated strictly following the manufacturer’s instructions.
  3. Lice re-infestation. It is worth checking the hair of all household members to rule out such a possibility.