Head lice are crab-like parasites that slowly crawl on the scalp and hair roots. They feed on human blood and cause itch. Head lice are fairly common in schools, are very contagious and sometimes cause real epidemics. Characteristic of this infection is that it only occurs in the hair on the head.


Close contact between people is the main way in which head lice can spread. Because the lice can only crawl from one place to another, contamination takes place via direct hair contact. Head lice can easily spread, especially at school. By playing and sitting close together, lice walk from head to head.
Female lice lay four to eight eggs a day and live under normal circumstances thirty to fifty days. An egg (nit) hatches after about seven days. Then it takes another seven to ten days before it has grown up.


Head lice feed on the blood of humans that they obtain by bites into the skin. The main symptom of head lice is itch and rash, caused by the saliva of the lice that is put into the skin during blood sucking. When the itch leads to scratching, wounds may arise which, in turn, can be infected by bacteria. This can lead to painful inflammation. Head lice are two to four millimeters in size.


A person can make the diagnosis of head lice by checking hair close to the scalp for lice and nits. With the aid of a fine lice comb, lice and nits can be caught. The difference between nits and dandruff flakes can be seen by looking whether the white flakes stick to the hair. If that's the case, they are likely nits. Dandruff is easy to remove. Head lice are contagious. If one family member has them, others may have them as well. It is advisable to check everyone for head lice each few days.


There are three treatment methods:


With proper treatment, a person can get rid of head lice. However, one may hit a new plague. Reduce that risk by keeping the house clean and avoiding contact with other infected people until they have been treated.