Head lice are tiny insects that feed on blood from the human scalp. An infestation of head lice is called pediculosis capitis and it most commonly affects children. Head lice usually result from direct transfer of lice from the hair of one person to the hair of another.
A head lice infestation is not an indication of poor hygiene or unclean living environment. Head lice don’t carry bacterial or viral infectious diseases.
Head lice can be treated with over-the-counter and prescription medications.
Symptoms
Common symptoms of head lice include:
- Itching: Itching on the scalp, neck and ears is the most common symptom. The itching is an allergic reaction to louse saliva.
- Lice on scalp: Lice may be visible but they are difficult to spot due to their small size and quick movement.
- Lice eggs (nits) on hair shafts: Nits stick to hair shafts. Nits are more easily spotted around the ears and the hairline of the neck.
Causes
A head louse is a tiny, tan or grayish insect that feeds on human blood that it extracts from the scalp. The female louse produces a sticky substance that adheres each egg to a hair shaft, which is a perfect environment for incubating eggs.
Transmission
Head lice crawl but they cannot jump of fly. Transmission of a head louse from one person to another is most often by direct contact. Therefore, transmission most often occurs within a family or among children who have close contact at school.
Indirect transmission is not likely but lice may spread by items such as:
- Hats and scarves
- Brushes and combs
- Hair accessories
- Headphones
- Towels
- Pillows
- Upholstery
Risk factors
Head lice are primarily spread by head-to-head contact; therefore, the risk of transmission is highest among children and young people who go to school together.
Complications
Scratching an itchy scalp from head lice infestation can potentially cause for the skin to break making one susceptible to an infection.
Treatment
In general, the recommended treatment for head lice is an over-the-counter medication that kills lice and some of the eggs. Two treatments are usually necessary to kill all the eggs.
OTC medications may include:
- Permethrin
- Pyrethrin with additives that enhance toxicity
Prescription medications
If OTC medications are ineffective, a doctor may recommend prescription medications, such as:
- Benzyl alcohol kills lice by depriving them of oxygen
- Malathion applied as a shampoo and left to dry naturally. During this process it destroys the lice
- Lindane is medicated shampoo with a risk of severe side effects
Prevention
It is difficult to prevent the spread of head lice among children in school or in child care facilities. This is because there is so much close contact for direct transmission. Therefore, it is a good practice for children to keep their garments separate from other children’s garments and not to share brushes, hats or scarves.
