What causes the itch of head lice?
When a head louse sucks blood, it injects some of its saliva into the wound, which prevents the blood from clotting.
It does this to keep the blood flowing well so that it can drink enough blood.
It's this saliva that can cause itching, provided you have an allergic reaction to it.
When do you get the itch
In the case of an allergic reaction, it can take about 2 weeks after the initial infestation before you begin to feel the itch. This is referred to as the incubation period.
The itching can even persist for 2 weeks after the infestation has been eliminated.
Approximately 53% of people are not allergic, and they don't experience any itching, even if they have hundreds or thousands of lice.
The annoying itching sensation can sometimes disappear for a while and later return.
Especially in the evening and at night, more people complain about itching.
The degree of itching can also increase as more lice are present on the head.
More lice means more lice bites, and for those who experience the typical itching from lice bites, this means more itching.
The advantage of the itch
The characteristic itching caused by lice bites is unpleasant, but it also has an important advantage: it serves as an early warning sign of an infestation. People who are allergic to lice bites usually detect an infestation at an earlier stage. In individuals without an allergic reaction, head lice are often only discovered at a later stage, when a large number of lice and eggs are already present. This makes complete elimination considerably more difficult, as anti-lice shampoos and lotions can never guarantee the removal of all eggs. The greater the number of eggs, the less effective the treatment becomes.
The downside of the itch
The downside of itching is, of course, excessive scratching, which can damage the scalp. This may lead to irritation, small wounds, an oily scalp and tangles in the hair.
To soothe and care for the scalp, we recommend the Superli Menthol Shampoo. It gently yet thoroughly cleanses the hair and scalp while providing a calming effect.
For daily relief from itching, the Scalp Tonic offers genuine comfort and a long-lasting sensation of freshness.
Tip: Don’t scratch with your nails, but with your knuckles!
In people with long hair, it's often observed that lice prefer the skin on the neck, where they descend along the long hairs.
Once they've fed, they climb back up to the warm scalp, leaving behind clearly visible lice bites that can be quite itchy.
Does itching necessarily mean I have head lice?
No, itching can have many causes.
Changes in the weather, a dry scalp, reactions to hair care products, and even some lice treatments can actually cause itching because they may not always be gentle on the scalp.
And then there’s the psychosomatic type of itching, the kind we all sometimes experience simply because we think about lice or hear people talking about it.
Psychosomatic itching feels exactly the same as physical itching, namely the sensation of crawling lice on your skin.
But the ironic part is that you can't actually feel lice crawling!
Over the thousands of years they've been living on our heads, lice have evolved to be completely unfelt and unnoticed in our hair.
The only physical itching you might feel is from the lice bites, the reaction to their saliva.
So people can mistakenly think they still have head lice just because they continue to experience psychosomatic itching.
This itching persists precisely because they keep thinking they are infested.
It creates a vicious cycle perpetuated by this incorrect self-diagnosis.
Ekbom Syndrome
However, sometimes, it has a deeper cause, namely when someone suffers from Ekbom Syndrome, also known as ‘Delusional Parasitosis’.
These are people with prolonged (itching-) complaints who are irrationally convinced that these are caused by lice (or other parasites) without actually having lice.
More about this can be found on our page, specially dedicated to the Ekbom Syndrome.
