Lice are small wingless parasitic insects that live on the scalp and feed on human blood. They are highly contagious and spread easily through head-to-head contact and by sharing items like combs, hats, helmets, hair ties, and headphones. Getting rid of lice quickly and effectively is important to stop the itching and prevent spreading them to others.
How do you get lice?
There are three types of lice that infest humans:
- Head lice – These live and breed in the hair and scalp.
- Body lice – These live and breed in clothing and bedding and come onto the skin to feed.
- Pubic lice – These infest the pubic hair and other coarse body hair.
Head lice are the most common and are easily spread by head-to-head contact. This allows crawling lice or their eggs (nits) to transfer to the hair of an uninfested person.
Less commonly, head lice can spread by sharing items like combs, brushes, hats, helmets, hair ties, headphones, or other personal items. It’s also possible to transfer head lice by resting one’s head on infested furniture or carpet at home or school.
Signs and symptoms
Signs and symptoms of head lice include:
- Itching of the scalp, neck, and ears
- Tickling feeling that something is moving in the hair
- Irritability and difficulty sleeping due to the itching
- Small red bumps or sores on the scalp, neck, and shoulders from scratching
- Seeing lice or eggs (nits) in the hair
Lice can crawl and make the scalp itch. The itching is caused by an allergic reaction to the saliva that lice inject as they bite the scalp to feed on blood. Head lice usually survive for less than 1-2 days off the scalp as they require human blood to live.
Finding lice and eggs
Checking for lice and eggs (nits) in the hair is important to identify an infestation. Look for:
- Living lice – These are small (2-3mm long), wingless insects. They avoid light and are difficult to see.
- Dead lice – These may appear red or brown.
- Eggs (nits) – These look like tiny yellow, tan, or brown dots glued to the hair near the scalp. They are hard to remove.
Live eggs will hatch in 7-10 days, so it’s key to eliminate them before they do. Lice can lay around 6 eggs per day, so infestations can multiply quickly.
Treating and preventing head lice
There are a few options for treating and getting rid of head lice:
Lice combs
Special fine-toothed lice combs can remove live lice and eggs when used correctly. Comb the hair in sections, combing each section methodically from root to tip. After each stroke, wipe the comb on a white paper towel to spot live lice. Combing may need to be repeated every 2-3 days for 2 weeks to catch newly hatched lice.
Medicated lice shampoos
Shampoos containing insecticides like permethrin or pyrethrins can kill live lice when applied to dry hair and left on for 10 minutes before rinsing out. Follow instructions carefully. However, shampoos do not kill all eggs, so combing and repeat treatment is often needed.
Oil treatments
Applying heavy oils like olive, coconut, or tea tree oil can suffocate and kill lice. Apply to damp hair, cover with a shower cap for at least 30 minutes, then wash and rinse well. Oils also make combing easier by stuns lice and loosening nits. Repeated applications may be needed. Oils are not enough on their own and should be combined with combing.
Medicated lotions and sprays
Over-the-counter lotions and sprays containing ingredients like permethrin are applied to dry hair and left on for 10 minutes or longer before rinsing out. This kills live lice but not unhatched eggs, so repeat applications are often needed.
Prescription medications
For severe cases, oral medications like ivermectin and topical prescriptions like malathion lotion may be options. These are only available with a doctor’s exam and prescription.
Nit removal
Eggs attached within 1⁄4 inch of the base of the hair shaft require removal by combing or picking out with fingernails or tweezers. Vinegar can help loosen eggs for easier removal. There are also special egg removal combs.
Cleaning methods
The following cleaning steps can help eliminate lice and eggs in the environment:
- Machine wash all clothing, bedding, and towels in hot water then run through a hot dryer cycle for 20 minutes.
- Seal items that can’t be washed like stuffed animals in a plastic bag for 2 weeks.
- Soak combs, brushes, hair accessories in rubbing alcohol or lice solution for 5-10 minutes.
- Vacuum carpets, furniture, mattresses thoroughly.
Avoiding head-to-head contact
Limiting head-to-head contact with an infested person can prevent spread. Kids should avoid sleepovers, camps, play dates, sports activities, and close play like hugging until cleared by a doctor.
Who is at risk for getting lice?
Anyone can get head lice but preschoolers, elementary school-age children, and the parents of infested children are most commonly infested. Girls get head lice more often than boys. African-Americans rarely get head lice possibly due to the shape of the hair shaft making it harder for lice to attach.
When to see a doctor
See your doctor if:
- You are unsure if it’s lice versus dandruff, ringworm, or another condition
- Self-care steps did not rid your child’s scalp of lice after 2 weeks
- You believe your child may have a secondary skin infection from scratching
- Your child experiences persistently swollen neck glands
- You want a prescription medication because over-the-counter products did not work
Doctors can diagnose an active case of head lice by looking closely at the scalp for live lice and eggs. They may use a special fine-toothed lice comb to detect live bugs.
Home remedies
Some home remedies like mayonnaise and Cetaphil are thought to help remove nits and lice but clinical evidence for these approaches is lacking. Most home remedies should only be used as an adjunct treatment together with approved lice products and nit combing. The following are some popular home treatments:
Mayonnaise
Applying a thick layer of mayonnaise to the hair and scalp then washing out after 30 minutes is said to stun lice and make combing easier. The effectiveness is uncertain. Use a shower cap and repeat weekly along with other methods.
Vinegar
White vinegar is believed to loosen nits so they can be more easily combed out. Dilute vinegar with water, apply to damp hair, rinse with clean water after 15 minutes. Repeat every few days.
Petroleum jelly
Applying petroleum jelly liberally to suffocate lice is a common home treatment. Use a shower cap overnight with once weekly use. Comb out any dead lice. Cleanse hair thoroughly the next morning to remove residue.
Cetaphil
Work Cetaphil Gentle Skin Cleanser into damp hair until saturated. Cover with a shower cap for 2-3 hours then comb thoroughly before shampooing out. This is thought to kill live lice and aid nit removal but clinical evidence is limited.
Salt
Some claim that mixing equal parts salt and vinegar then rubbing into the scalp can dehydrate and kill lice. There is little clinical evidence that a salt treatment kills lice or eggs effectively.
Essential oils
Oils like tea tree, eucalyptus, lavender, olive, and coconut oil may have some pediculicide effects by suffocating lice. Research shows essential oils work best when combined with proven treatments. Do not apply undiluted oils directly as they can irritate skin.
Nit combing
Meticulous wet combing with a quality lice comb to manually remove nits and lice every 2-3 days for 2 weeks is critical. This should be used along with any lice product for best results. Nits farther away from the scalp may remain but will not likely hatch.
Mayo and vinegar rinse
A popular home remedy combines 1 tablespoon mayonnaise with 2 tablespoons vinegar applied to damp hair. Cover hair with a shower cap or towel for at least 15 minutes then rinse and follow up with a lice comb. This is believed to stun lice and loosen egg casings for easier removal.
Blow drying
Use a hair dryer on the hottest setting to aim continuous hot air at sections of the hair to dehydrate and kill lice. Carefully avoid burning the scalp by holding the dryer 6 inches away and continuously moving around sections of hair. Repeat daily.
Smothering agents
Applying agents like petroleum jelly, olive oil, coconut oil, or hair conditioner liberally to the scalp can help smother lice. Cover hair overnight with a shower cap. Shampoo out the next day and follow up with thorough combing. This can be drying so use sparingly.
Natural oils and extracts
Some natural oils like tea tree oil, lavender oil, eucalyptus oil, jojoba oil, and neem extract may have a physical or chemical effect on lice. However, most essential oils must be mixed with a carrier oil or shampoo to avoid irritating sensitive scalp skin. Do not apply undiluted oils directly to the scalp.
Hair gels and pomades
Thick hair gel, pomade, or regular hair conditioner applied generously to coat each strand of hair may help deprive lice of oxygen. Cover hair overnight with a shower cap. Cleanse thoroughly the next day and follow up with nit combing. Results vary.
Vinegar rinse
Mixing 1-2 cups of vinegar with 1 cup of warm water and pouring over damp hair is thought to help loosen nits for easier removal by combing. Let set for 15 minutes with a shower cap then rinse clean. Vinegar has not been clinically proven to kill active lice.
Duct tape
Wrapping duct tape sticky-side out around a hand then running fingers through the hair to pick up eggs is a home remedy for nit removal. However, this is often not as effective as specialized nit combs. Caution is needed to avoid excessively pulling hair.
Can lice be prevented?
Prevention involves both avoiding infested heads and regular screening to enable early detection and treatment.
- Teach children to avoid head-to-head contact and sharing of items like combs, hats, helmets
- Check all household members’ heads for lice once a week. See a doctor if found.
- Tie back long hair and braid if possible
- Use a protective swimming cap at pools and splash parks
- Coat hair strands thoroughly with gel or hairspray to potentially repel lice
- Clean shared helmets and headgear between users
- Machine wash all bedding, towels, clothes in hot water weekly
Promptly treating those affected and avoiding direct head contact until clear of lice are the best preventative steps.
Lice vs dandruff
| Lice | Dandruff |
|---|---|
| Caused by parasitic insects that bite and feed off scalp | Caused by shedding of dead skin cells |
| Moves quickly away from light source | Non-moving, flakes come loose with scratching |
| Causes very itchy scalp | Can cause mild scalp itching |
| Eggs (nits) visibly glued at hair roots | No eggs present |
| Needs medicated shampoo or tea tree oil | Treat by reducing oil production with medicated shampoo |
Lice vs dandruff – the key differences
While lice and dandruff both cause scalp itching and flaking, there are some key differences:
- Dandruff is caused by irritated oily skin whereas lice are living insects.
- Dandruff symptoms improve with medicated shampoo. Lice requires removal of bugs and eggs.
- With dandruff, white flakes are visible in hair and on shoulders. Lice causes pinhead sized eggs glued near scalp.
- Dandruff does not spread from person to person. Lice is highly contagious, spreading by head contact.
- Gently scratching and shaking hair reveals loose dandruff. Lice move quickly away from light to avoid detection.
Checking for actual insects, eggs, and movement can help identify lice versus dandruff flakes.
Conclusion
Getting rid of head lice quickly is important to avoid spreading and itching. An integrated approach works best:
- Using an over-the-counter or prescription lice killing product
- Nit combing 2-3 times per week for 2 weeks to manually remove bugs and eggs
- Cleaning to eliminate lice around the home
- Avoiding direct head contact until fully cleared
Home remedies like oils and vinegar can help but are most effective when paired with approved lice treatments and thorough nit combing.
With an aggressive approach, most cases of head lice can be eliminated within 2 weeks. See a doctor if self-care fails to eradicate lice from your child’s scalp.