Head lice

Causes 

A head louse (plural is lice) is a tan or grayish, tiny six-legged insect about the size of a flax seed. It clings to the scalp and hair and feeds on human blood. 

The lice eggs or nits hatch into nymphs, which become full grown lice. Adult lice mate in order to produce more nits. The three stages of life cycle are explained in detail:

Nits are firmly attached to the hair shaft by a glue-like sticky substance produced by a female louse. They are usually yellow or white in color, oval in shape and 2-3 mm in length. Nits take about six to nine days to hatch. They are not easily visible and are often confused with dandruff.

Nymphs

A nit hatches into a small louse called a nymph. The nymphs require human blood for survival and mature into adults in about seven to ten days after hatching. 

Adult lice 

Adults have a life of about one month. The female lays 6 to 10 eggs a day and are usually larger than males. If the louse falls off a person, and does not get human blood, it dies within a day or two.

Symptoms Of Head Lice

In most cases, head lice are not immediately noticed after infestation. The eggs laid by head lice are called nits. It is when you experience intense itching on the head and appearance of nits, does it indicate head lice. Some of the common signs and symptoms of head lice are:

• Itching or the urge to scratch

• Tingling or a crawling sensation like feeling of something moving in the hair

• Difficulty in sleeping due to itching as lice are active at night

• Red sores on the head, neck, and shoulders (caused by scratching)

• Swollen lymph nodes

Head lice and their eggs are most frequently seen by looking closely near the hair root. They are most commonly found behind the ears and upper part of the back of the neck. Rarely, they may be seen on the eyelashes, eyebrows, or beard. 

Risk Factors for Head Lice

While most people think head lice are caused due to unclean hair and scalp, this is not true. Having head-lice is not a sign of poor personal hygiene or an unclean living environment. Head lice don't carry bacterial or viral infections. They feed on blood and can affect almost anyone. 

However, girls are known to be more at risk than boys to get infected because they tend to have more head to head contact as compared to boys. Also, girls with long, thick and curly hair may find it hard to fight lice infestation as it makes it difficult to find the parasites in their hair.

Head lice cannot jump or fly. They can only crawl. Hence, transmission from one person to another usually happens by direct head-to-head contact. It is often seen within a family or among children who have close contact at schools, play groups etc.

Indirect transmission is not very common, but one may be at risk of getting head lice while sharing items like:

• Combs

• Hats or scarves

• Towels

• Helmets

• Bedding

• Hair brushes or Hair accessories

• Headphones

• Clothes

Diagnosis Of Head Lice

As head lice are around 2- 3 mm long and have the ability to hold tight onto the hair strands and crawl along, it makes it difficult to find them in your hair. The only way to find them is through combing and manual examination.

1. Thorough combing (using a fine-tooth comb) of wet hair, especially at the back of the head where lice are commonly found, may help in finding lice.

2. Manual examination of the hair may show nits fixed to the base of hair shafts. They can look like dandruff or dirt. Pull the little speck with your fingers. While dandruff and dirt can be removed, nit usually remains stuck. It can be tough to find a nymph or adult louse as they move very fast. 

Prevention Of Head Lice

The first and foremost tip you need to keep in the mind is the fact that there is no effective method to prevent head lice. But there are ways to stop the spread of head lice from one person to another. So if anyone in your family suffers from head lice, here are a few tips that you must follow.

• Wash clothes, bedding, and towels in hot water and dry them on the hottest setting. 

• Opt for dry cleaning if you can’t wash these items at home.

• You can use a vacuum to clean furniture, carpet, and car seats. 

• Things that cannot be washed such as soft toys and pillows should be put into a plastic bag and sealed for at least two weeks.

• Do not share a bed with a person infested with lice as there is a high possibility of lice getting transferred through direct head to head contact.

• Do not use the combs, brushes and hair care products used by a person who has head lice.

• It is wise to throw away or sterilize and use for the future.

• Do not send your child to school if he/she has head lice.

Specialist To Visit

If you experience severe itching and scratching due to head lice infestation or if you find it difficult to sleep at night, then it is wise to consult a doctor and get it treated immediately. For this you can either visit a:

• General Physician

• Pediatrician 

• Dermatologist

Treatment Of Head Lice

Once lice have settled on your scalp, they don’t go away on their own again. In most cases, treatment is aimed at killing the parasites by suffocating them. 

Some of the common Over-the-counter treatment options for head lice include:

1. Pyrethrin

It is an over-the-counter medicine that contains naturally occurring pyrethroid extracts. It can kill only live lice and not nits (unhatched eggs). This is why a second treatment after 9 to 10 days of first treatment is recommended to kill the newly hatched lice and prevent them from producing new eggs. It is approved for use in kids above 2 years and older.

2. Permethrin

It is a synthetically available form of the naturally occurring pyrethrin extracts. Permethrin lotion 1% is an FDA-approved product for the treatment of head lice. It is safe and effective when used as per the doctor’s advice. Just like pyrethrin, it kills live lice but not unhatched eggs, so a second dose is recommended after 9 to 10 days to be effective against head lice.

Some of the common prescription medications for head lice include:

1. Benzyl alcohol lotion, 5%

An FDA-approved product for head lice treatment, it is found to be safe and effective when used as per doctor’s direction. It kills lice but not unhatched eggs, so a second treatment after 7 days of the first is recommended.

2. Ivermectin lotion, 0.5%

This formulation prevents newly hatched lice from surviving. It is known to be effective when applied on dry hair without nit combing. It can be applied once to dry hair and then rinsed with water after 10 minutes. Ivermectin is also available as a tablet. It can be taken if other topical treatments fail to eliminate lice.

3. Malathion lotion, 0.5%

It is known to kill lice and also kills some eggs. A second treatment after 7-9 days of the first is advised to make it more effective in action. It is recommended for use in kids above 6 years and older. As this lotion is flammable, it is not advisable to not use electrical devices such as hair dryers after applying this lotion or when the hair is wet.

4. Spinosad 0.9% topical suspension

It kills both live lice and unhatched eggs, hence retreatment is not required. Nit combing is also not required. It is approved for the treatment of children above 6 months and older.

5. Lindane shampoo 1%

It is usually recommended for use as a second-line treatment only as overuse or misuse of this drug can cause toxic side-effects on the brain and nervous system. It is not advised for treatment in people with HIV, seizure disorder, pregnant women, breastfeeding women, and those with skin sores. Also, retreatment is strictly not recommended. 

Home-care For Head Lice

Here are some tips to deal with head lice at home:

• Wet combing is usually preferred to remove lice from hair for young children. Use a regular brush or comb to remove tangles from wet hair before using a special comb.

• Use a special fine-toothed comb to carefully comb out nits and lice from hair. Pull the comb through the hair from roots to ends. Comb the entire head at least twice.

• The nits (lice eggs) mature in 5-7 days so it is important to comb every day for about 2 weeks to ensure you get rid of all the lice.

• You can get a prescription for kids if combing doesn’t work and the infestation is severe.

• Beware of using natural remedies like olive oil or butter and toxic substances such as kerosene to get rid of head lice as these might cause more harm than good.

Complications Of Head Lice

Head lice if left ignored can lead to severe itching and scratching of the head. If a person scratches an itchy scalp from a head-lice infestation, it is possible for the skin to break and develop an infection. In the worst case scenario, you might need to visit a dermatologist to get a secondary bacterial infection of the skin treated due to head lice.

Alternative Therapies for Head Lice

A number of household products are commonly used for the treatment of head lice. But do not use natural remedies such as olive oil, butter, petroleum jelly and mayonnaise to get rid of head lice. It is believed that these remedies work by suffocating the lice but do no good as lice are difficult to suffocate.

Avoid using toxic compounds like gasoline and kerosene to get a risk of lice. There is no research evidence on the same. Moreover, it can lead to serious injury.

Living With Head Lice

Head lice can be very annoying, but they are not dangerous and they don't spread any disease. Neither are they a sign of poor hygiene. They need blood for survival which is not dependent on hygiene of the head or surroundings. They can be managed by various treatment options and various other measures like:

1. Do not use combs, hair brushes, hats, bedding, towels, or clothing of a person affected with head lice.

3. The lice and eggs can be removed to some extent with the help of a very fine toothed comb on wet hair.

4. Medication includes pediculicides (medicines which kill lice) with ovicidal effect (which kill nits or unhatched eggs) which is the most important treatment.

5. To prevent reinfestation, nits are killed by using hot air (slightly cooler than a hair dryer) for 30 minutes.

6. Wash all clothes, beddings, and combs in hot water with detergent.

7. Repeat treatment after 7 to 10 days.