Extremely Itchy Scalp
Frequent scalp itching is a major symptom of head lice. According to the American Academy of Dermatology Association [2], itching is the most common symptom of an infestation. This could be because the presence of the lice on your head badly irritates your scalp. This reaction is specifically caused by lice saliva [3]. The intensity of this symptom varies from mild to severe. In some people, the itching is so bad they almost cannot keep their fingers away from their heads. Scratching too much can lead to the development of small cuts or sores on your scalp. This is more common in children.
The severity of your itching sometimes has to do with the lice burden on your head, but this is not always the case. Having a few lice in your hair should mean your scalp will not itch as much as that of someone who has plenty, but if your scalp is very sensitive to the lice, even a small number can trigger severe itching. Still, the more lice you have on your head, the more likely it is that your scalp will itch intensely.
Itching is not always limited to the scalp. It is also common to experience itching on the neck and around the ears. These areas are all within the range of head lice. During a person’s first head lice infestation, this allergic reaction to the bites of these insects may be delayed for as long as four to six weeks [4] post-infestation.