Head lice (hair lice)

Occurrence: Head lice (Pediculus humanus capitis) is very similar to body loopbut are much more common in the Western world. Although both children and adults can get head lice, they are most common in children. Head lice are sometimes also called hair lice.

Food: Head lice feed by sucking blood from humans. This results in itching and possibly also small sores and scabs on the scalp. Lice are highly dependent on their hosts and can survive a maximum of 24 hours without blood and body heat.

Treatment: Head lice are most easily treated with lice repellent. Alternatively, lice can be combed out with conditioner, but this is more time-consuming. In addition, checking for lice afterwards is an important part of treatment. There is no need to wash bedding or do extra cleaning, as head lice are in practice only transmitted through direct contact (hair-to-hair).

Read more about head lice treatment here.


Description of the head louse

Head lice are very similar to body lice and it is only possible to tell the difference between the two species with a microscope.

Head lice are 2.5 - 3 mm long and have 6 legs. They have no wings and can neither fly nor jump.

Their colors can vary greatly; they can be white, brown or dark grey (and colors in between).

After ingesting blood, they usually become more reddish in color. This color disappears when the digestion of blood starts.

Head lice are 2.5 - 3 mm long

Head lice are 2.5 - 3 mm in length, but their nymphs can be as small as 0.5 mm

Be aware that the nymphs - the precursors to the adult lice - are similar to the adult lice, but smaller. There are three nymph stages, usually 1, 1½ and 2 mm long, but they can be as small as ½ mm in the first stage. You can read more about their lifecycle here.


Head lice eggs

The eggs of the head louse are small, white and oval. The female louse attaches the eggs to individual hairs (one egg per hair) on the scalp. The eggs are often located some distance up the hair because it typically takes a while from the time the eggs are laid until they are discovered.

Eggs hatch after 5 - 10 days (typically 7 - 10). However, not all eggs hatch (unhatched eggs remain unhatched after 10 days).

Head lice eggs are very small, white in color and oval in shape

Head lice eggs are small, white and oval-shaped, and are attached to individual hairs


Symptoms and symptoms

Head lice can be found in the hair and scalp, and often around the neck or behind the ears. The eggs are small and round or oval-shaped. They are attached to the hair roots and cannot slide up or down the hair they are attached to.

The main symptom of head lice is itching, but some people also experience a tickling sensation or movement on the scalp. However, these symptoms don't have to appear immediately; in some cases, they can start weeks - or even months - after the lice have started to spread.

When scratching, the skin on the scalp becomes irritated, which can result in clear fluid secretion and the formation of scabs or small sores. In some cases, this leads to infection, which can cause the lymph nodes in the neck and behind the ears to become swollen and tender. In very severe cases, hair loss and thickening and darkening of the skin in the affected areas can occur.

For some, the persistent itching can also lead to irritability.


How do you get head lice?

Children as well as adults can get head lice and it always happens through close contact - especially hair-to-hair contact.

Children are often infected during play, school, sports, camps, sleepovers, etc. where they are in close contact with other children for long periods of time.


Risk factors

The following increase the risk of getting head lice:

  • Going to school or daycareChildren often play close together and share things like hats, hairbrushes, etc. which increases the risk of them contracting head lice.
  • Being with childrenBecause children have lice more often than adults, adults who spend a lot of time with children are at increased risk of getting lice. This applies to parents, educators, etc.


Avoid head lice

Head lice are easily spread between children because they are in close contact with each other and their hair can come into contact.

If you or your child have head lice, you can avoid transmitting them to each other by avoiding all head-to-head contact (hair-to-hair contact) - both inside and outside the home. Prolonged close contact with people who have lice should be avoided.

If you have school-aged children, it's a good idea to regularly check their scalp for lice. This will prevent lice from spreading to the rest of the family. You can also comb their hair with a lice comb to catch any lice before they develop. Of course, for this to work, you need to use the comb frequently.

Long hair can be put up in a bun or ponytail to reduce the risk of it coming into contact with lice-infected hair.

If the head lice problem is recurring or persistent, you can choose to cut your hair short or even shave your head completely bald. Hair should be a maximum of 0.5 cm long to avoid lice altogether.

You can read more about prevent and avoid lice here.


Read also our article on head lice treatment here.