What causes head lice infestation?

Lice (singular: louse) are tiny insects (known as parasites) that are most commonly found on the head (scalp). Hence, they are also referred to as ‘head lice’. The other sites where lice can be seen are behind the ears and on the back of the neck.
Head lice infestation is medically known as ‘pediculosis capitis.’ It is caused due to the spread of lice from one person to another through ‘head-to-head’ (hair-to-hair) contact. Head lice cannot fly or jump but can crawl at a rapid pace on the scalp. They feed on the blood of the person whom they have infested.
What are the signs and symptoms of a head lice infestation?
The most common symptom of head lice infestation is intense itching, which is an allergic reaction to the saliva of the lice. Other signs and symptoms include:
- Feeling that something is crawling on the head
- Light brown bugs (head lice) moving swiftly on the scalp
- Yellow, brown, pin-sized lice eggs (nits) glued to the hair
- Red bumps (sores) on the scalp, head, or shoulders
Some children may also have
- Swollen nodes (glands) on the neck
- Pink eye (an eye infection)
It is possible that children may have head lice on the scalp but do not develop any of the signs and symptoms for several weeks.
What is the treatment of head lice infestation?
Getting rid of lice completely is a troublesome process and needs patience.
A head lice infestation will usually take about 4 to 6 weeks to clear up even with treatment.
The doctor will initially advise using over-the-counter (OTC) products that kill lice and some of the nits in the scalp of the child. The instructions written on the bottle or product information leaflet should be read before using the product.
OTC medications:
- Permethrin 1% (Nix): This medication is available in the form of lotion, which needs to be applied to the hair for 10 minutes followed by hair wash. It kills only the lice and not the nits. Hence, the application needs to be repeated after 9 to 10 days to kill the hatched eggs before they can produce new eggs.
- Pyrethrin in combination with piperonyl butoxide (A–200, Pronto, R&C, Rid, Triple X)
After applying any of the OTC lotions, it is necessary to comb the hair from the roots to the tips to remove any lice. This should be done once in a day to remove all the dead lice and their eggs.
Prescription medications:
If OTC medicines have failed to eliminate the lice, the doctor may recommend any of the prescription medicines that include:
- Ivermectin (Sklice)
- Spinosad (Natroba)
- Malathion
All the members of the family need to be treated because they may have been infested with head lice as well. The other general measures to stop the spread within the family/house include:
- Use of the hot water cycle of the washing machine to wash clothes
- Dry cleaning of the clothing that is not washable (coats, hats, scarves, etc.)
- Storing or dry cleaning all clothing (such as comforters), which cannot be washed, and then placing them into a sealed plastic bag and keeping them away for at least 2 weeks
- Soaking combs and brushes for 1 hour in rubbing alcohol or washing it with soap and hot water
- Vacuuming the floor and all the furniture in the house
How can head lice infestation be prevented?
It is difficult to prevent the spread of lice amongst school children because there is so much contact that happens between them. However, here is what can be instructed to the children:
- To keep the garments away from other children's garments (by hanging on a hook)
- To avoid sharing personal items, such as combs and hats
- To not lie on the beds or couches that have been used by other children

QUESTION
What percentage of the human body is water? See AnswerTop Head Lice Causes, Symptoms, and Treatments Related Articles
Bedbugs vs. Lice
Bedbugs are small blood-sucking parasites that feed on mammals and birds. Some people do not have any symptoms of bedbug bites while others have them they include pain and reddish-colored skin lesions where the bite is. Bedbugs are found in temperate and tropical climates worldwide. Bedbugs usually feed every five to 10 days. Bedbug bites usually do not need treatment. Bedbug infestations are difficult to get rid of. Bedbugs are a problem worldwide, are resurging. There are three types of lice, head, body, and pubic. Head lice is a grey-white animal about the size of a sesame seed and can be mistaken for dandruff. Head lice are transmitted from the body to other household items. They produce between seven to 10 eggs (nits) annually. Head lice is transferred from head-to-head contact. Body lice are slightly bigger than head lice and look like head lice. Body lice is transferred from human to other household items. Pubic lice or "crabs" is distinctly different from the head and body louse. Pubic lice in adults is transferred by direct sexual contact. Children and others get pubic lice via nonsexual transmission from their parents, relatives, and friends who share clothing. Lice bites are bluish in color sore that develop on different areas of the body. Condoms do not prevent from getting pubic lice. The different types of lice have different treatment. Lice can be eradicated from your home.benzyl alcohol
Benzyl alcohol is a component of creams and ointments applied topically to relieve pain from cold (canker) sores or blisters in the mouth and gum irritations, and to treat head lice infestation (pediculosis). Common side effects of benzyl alcohol include itching (pruritus), redness (erythema), application site reactions, pain, irritation, reduced sensation (hypoesthesia), loss of sensation (anesthesia), eye irritation, dry skin (xeroderma), skin rash, skin peeling (desquamation), skin picking (excoriation), tingling and numbness (paresthesia), dermatitis, seborrheic dermatitis of scalp, and burn (thermal) injury.Common Medical Abbreviations & Terms
Doctors, pharmacists, and other health-care professionals use abbreviations, acronyms, and other terminology for instructions and information in regard to a patient's health condition, prescription drugs they are to take, or medical procedures that have been ordered. There is no approved this list of common medical abbreviations, acronyms, and terminology used by doctors and other health- care professionals. You can use this list of medical abbreviations and acronyms written by our doctors the next time you can't understand what is on your prescription package, blood test results, or medical procedure orders. Examples include:
- ANED: Alive no evidence of disease. The patient arrived in the ER alive with no evidence of disease.
- ARF: Acute renal (kidney) failure
- cap: Capsule.
- CPAP: Continuous positive airway pressure. A treatment for sleep apnea.
- DJD: Degenerative joint disease. Another term for osteoarthritis.
- DM: Diabetes mellitus. Type 1 and type 2 diabetes
- HA: Headache
- IBD: Inflammatory bowel disease. A name for two disorders of the gastrointestinal (BI) tract, Crohn's disease and ulcerative colitis
- JT: Joint
- N/V: Nausea or vomiting.
- p.o.: By mouth. From the Latin terminology per os.
- q.i.d.: Four times daily. As in taking a medicine four times daily.
- RA: Rheumatoid arthritis
- SOB: Shortness of breath.
- T: Temperature. Temperature is recorded as part of the physical examination. It is one of the "vital signs."
Head Lice
Head lice infection is called pediculosis. Lice are parasites that feed on blood and can be found on the scalp and hair of infected people. Signs and symptoms of head lice infestation include a tickling sensation, itching, and sores on the head. Head lice may be eliminated with various over-the-counter shampoos and washing all clothing and bed linens in the hot water cycle. Combs and brushes should be disinfected, and the floor and furniture should be vacuumed.Head Lice Picture
Head lice. This shows numerous lice as well as their grayish-white egg capsules (nits) stuck firmly on the hairs in a child.Head Lice Slideshow
Learn how to get rid of head lice. Lice attach themselves to the scalp and feed off of human blood. Discover head lice symptoms and learn what head lice look like for effective head lice treatment.Head Lice vs. Dandruff
Dandruff is a condition that causes dry flakes on the scalp. Lice are parasites. Head lice infestations are very contagious. Both head lice and dandruff have similar signs and symptoms: scalp itching and tiny white material on the hair shafts. Lice treatment involves the application of over-the-counter shampoos that contain permethrin or pyrethrin followed by nit and louse removal with a fine-toothed comb. Dandruff treatment incorporates the use of anti-dandruff shampoo.How Do You Get Rid of Lice Fast?
Learn what medical treatments can help with lice and speed up your lice recovery.ivermectin
Ivermectin is an antiworm (anthelmintic) medication used to treat intestinal strongyloidiasis and river blindness (onchocerciasis), types of diseases caused by parasitic roundworm (nematode) infestations. The FDA has not authorized or approved ivermectin for the treatment or prevention of COVID-19. Common side effects of ivermectin include itching, rash, hives (urticaria), skin (swelling) edema, fever, joint pain (arthralgia), inflammation of the synovial membrane on joints (synovitis), enlargement and tenderness of lymph nodes, and eye inflammation. Avoid use or use with caution if pregnant or breastfeeding.ivermectin topical
Ivermectin topical is a medication used to treat head lice infestation, and inflammatory lesions caused by a skin condition known as rosacea. Ivermectin topical is available as a cream to apply on rosacea lesions and as a lotion for application on the scalp and hair for head lice. Common side effects of ivermectin topical include skin burning sensation, skin irritation, dry skin (xeroderma), dandruff, eye irritation, red eye (ocular hyperemia), inflammation of conjunctiva (conjunctivitis), and skin inflammation.malathion
Malathion is a synthetic phosphorous compound (organophosphate) approved for topical use to kill head lice and also used off-label for pubic lice infestation that is resistant to other treatments. Do not use malathion on newborns or infants younger than 2 years old. Common side effects of malathion include skin and scalp irritation, stinging of skin, chemical burns (including second-degree burns), contact allergic sensitization, inflammation of the outer eye membrane (conjunctivitis) from accidental contact with the eyes.Natroba (spinosad)
Natroba (spinosad) is a prescription medicine used to treat the symptoms of head lice. Natroba may be used alone or with other medications. Serious side effects of Natroba include hives, rash, difficulty breathing, swelling of your face, lips, tongue, or throat; and severe dizziness.permethrin
Permethrin is a topical medication used to treat scabies and head lice infestations, available over the counter and by prescription. Do not apply permethrin to infants younger than 2 months old. Common side effects of permethrin include local discomfort (scalp), rash on the scalp, itching (pruritus), localized burning or numbness, localized swelling (edema), tingling of the skin, stinging of the skin, and redness of the skin (erythema). Consult your doctor if pregnant or breastfeeding.