Head Lice: How Do They Spread? Symptoms, Treatment and Prevention

How Head Lice Spread

Head lice usually spread by close contact with the infected person. They are common in crowded and unhygienic areas. Pets such as cats and dogs are not involved in spreading the head lice. Children between the age 3-11 years, especially girls are likely to get infected with head lice and spread that to their family members.

There are several ways by which a child contracts these parasitic insects, such as personal contact during sports activities, wearing infected clothes (hats or scarves), lying on infected person's bed or pillow and using their headphones, combs or towels. [1]

Head lice eggs or nits are frequently found behind the ears and near the neckline. They tend to appear darker if the host has darker hair. While sucking the blood, they inject saliva to prevent blood from clotting and feeds easily. This leads to itching sensation on the scalp. Also, female lice secrete a glue-like substance that help their eggs to remain attached in the scalp.

Head lice cannot fly or jump but they can move quickly between hairs, thanks to their six legs. They need a human host to survive and if they fall out from the head, they can die within two days.

Though head lice are considered a sign of poor hygiene, it always does not mean that you stay dirty. Sometimes, just a simple head-to-head contact may allow the lice to transmit to another person, no matter how clean is their hair.

Symptoms Of Head Lice

• Itching in the scalp [2]
• Tickling feeling that something is moving
• Sores or red bumps due to scratching the scalp
• Bacterial infection [3]
• Pink eye
• Lack of sleep during the night as they get more active during the hour.
• Seeing crawling bugs (usually when they grow up)

Risk Factors Of Head Lice

Younger children are likely to get infected as they spend most of their times together with other children during school and sports activities. [4]

Complications Of Head Lice

• Scratching the scalp too harshly may cause a break in the skin leading to bacterial infection.
• Darkening of the skin due to prolonged infestation of head lice.
• The spread of uncommon bacterial diseases (in rare condition) in places where good hygiene is extremely difficult.

Diagnosis Of Head Lice

Diagnosis is usually carried out by physical examination. They look out for crawling louse to confirm the cause as there are other factors responsible scalp itching such as dandruff, dirt, residues, dead hair tissues or other small insects. [5]

Another way is by using black light as nits with live lice tend to fluoresce when blacklight falls on them.

Treatment Of Head Lice

The treatment of head lice is not only limited to the person who is infected but also to other members who are staying with the person or sharing the bed. Common treatment methods include:

• OTC: Over-the-counter medicines to kill lice. It should be taken after proper consultation and depending on the child's age. [6]
• Medicated shampoos/creams: To kill lice. It is better to use expert-suggested items.
• Pediculicides: To kill nits to lice eggs.
• Picking by hand: Picking and killing the lice by hands.
• Fine-toothed comb: It should be done on wet hair.

How To Prevent Head Lice

• Avoid wearing another person's clothes, using their towels, headphone or pillows. [7]
• Avoid close contact with people who seem to always scratch their head.
• Keep an eye on your child's hygiene and look for signs of head lice (if they often scratch their head).
• Wash clothes immediately and dry-clean them if you have come in contact with an infected person.
• Soak combs in hot water or in soap water if an infected person or any person has used it.
• Clean the floors with a disinfectant.
• Avoid blow-drying your hair if you have applied any medicated creams.

Common FAQs

1. What causes head lice to begin?

Head lice can directly transfer from the hair of one person to another person's hair when they come in close contact. Poor hygiene, hair length or hair condition are not included in its infestation.

2. How do you kill head lice?

There are several ways to kill head lice such as OTC medicines, creams, medicated shampoos and fine-toothed combs. Some natural ways include applying tea tree oil or eucalyptus oil on the scalp.

3. Can head lice live on pillows?

Head lice can only survive on the scalp of their host (humans) by sucking their blood. When they fall on pillows or other objects like furniture, the starve and die within two days.

4. Do head lice go away on their own?

An adult louse lives for around 30 days. After mating, the female louse lays eggs (8/day) which are hatched within a week. In another week, the nits become visible and remain attached to the scalp. Head lice do not often go away on their own, but if you start taking precautionary measures before the eggs hatch, they may go within a week or two.