Head lice are tiny, wingless, parasitic insects that feed off of blood and live on your scalp. A lice infestation, called pediculosis capitis, is not due to poor hygiene. Lice spread through close personal contact and sharing belongings, such as hats. Using a special shampoo and fine-tooth comb can remove head lice. However, according to the Mayo Clinic, if this does not kill all of the lice, you may need to use a prescription shampoo.
Itching
The hallmark of head lice is intense itching. According to the Mayo Clinic, the intense itching is due to an allergic reaction to the saliva released by the lice when they are feeding. Red, irritated bumps can appear on your scalp, neck and shoulders. However, according to the Cleveland Clinic, the itching does not begin until two to three weeks after the infestation starts. In addition, the Mayo Clinic states that some people may not experience itching during the primary infestation of lice.
Adult Lice
Another sign is the appearance of adult lice on your scalp, most commonly behind your ears or along the back of your neck. According to the Mayo Clinic, the size of an adult louse ranges from a strawberry seed to three millimeters. Some lice can be removed by using a fine-tooth comb, though the majority must be killed by using a specific shampoo.
Lice Eggs
Lice eggs, or nits, are an indicator of a continuing infestation. Lice eggs are firmly attached to your hair shafts and cannot be brushed out of your hair. According to the Mayo Clinic, they resemble dandruff or "tiny pussy willow buds." Nonprescription shampoo can remove the lice eggs from your scalp. If the lice eggs are not killed, the lice infestation can continue.
