Where Do Lice Come From?

Lice are tiny parasites that live on the human body or in the hair. But, where do lice come from, and how can you get rid of them?

There are three different species of lice that infest people. None of the species of lice can be spread by pets, and transmission primarily occurs via person-to-person contact.

Where do HEAD LICE come from?

Head lice and nits (louse eggs) are the most common form of lice that infest people, primarily affecting school children.

Head lice are tiny, about the size of a sesame seed, and gray-white in color. The lice live and breed in the hair, attaching their eggs to the hair shaft where they hatch into nymphs after six to 10 days, becoming adults after a further 10 days.

Head lice do not have a preference for dirty hair. They are spread via direct head-to-head contact and via shared pillows, hats, headphones, brushes, and combs. A head louse can only live outside of its human host for a day or so.

Lice can be present without causing symptoms. However, the most common signs of head lice infestation are itching of the neck, scalp, and behind the ears. Diagnosis of a head lice infestation is usually made by directly viewing the nits under a “black light”, or by catching adults and nits by running a fine-tooth comb through the hair.

Where do body lice come from?

The body louse is bigger than the head louse, although they look similar. The body louse lives in the seams of clothing, moving on to the human host in order to feed.

Unlike head lice, body lice can survive for up to a month away from the human host. Body lice infestations are usually the result of poor personal hygiene and are common in communities where poverty and overcrowding are an issue.

The primary sign of body lice infestation is itching, especially in areas where clothing seams fit close to the body. Red, itchy marks are often visible on the body. Diagnosis is usually made by examining the seams of clothing for live lice or nits.

Where do pubic lice come from?

The public louse is different in appearance from the head and body louse. It is rounder in shape and has three distinct pairs of legs on either side of its body, hence its common name – the “crab” louse.

Pubic lice are transmitted from person-to-person, usually through direct sexual contact. Children can contract pubic lice from direct contact with their parents via bed sharing. Pubic lice cannot be caught from toilet seats and using condoms will not prevent an infestation.

The main symptoms of pubic lice infestation are itching and skin rashes in the affected areas. A bluish-colored sore may appear in the involved areas. Diagnosis is usually made by viewing crab-shaped lice attached to the pubic hair shaft.

Pubic lice infestation should be reported to your doctor, as there is also an associated risk of sexually transmitted disease.

How to treat head lice

  • Use a special fine-tooth louse comb, clear tape, and a strong light to locate and remove the lice and their eggs.
  • Wet comb the hair every two or three days, working through small sections at a time.
  • Treat lice with an anti-lice agent (available from pharmacies or from your family doctor) and repeat after 10 days to kill newly hatched nits.
  • Check all household members for nits and lice.
  • Wash bedding and clothing in hot water (at least 1400F) to kill the lice and nits.
  • Disinfect all combs and brushes.
  • Place non-washable items in plastic bags, seal them, and leave them for up to 10 days. Open the bags outside and shake the items out to dislodge any dead lice and nits.

How to treat body lice

  • Wash the whole body thoroughly.
  • Place all bed linens and clothing in the wash on a hot cycle to kill adults and nits. Dry the clothing on a hot drying cycle or place in direct sunlight.
  • Alternatively, destroy all bedding and clothing by burning – remember that nits can survive away from the body for up to 30 days.
  • Check all household members for lice and nits and treat those affected with an anti-lice agent as appropriate.
  • Vacuum all furniture and flooring. Be sure to burn the vacuum bag immediately afterward. If you have a cylinder vacuum, change the filters and burn the old ones. Wash out the cylinder with boiling water.
  • Treat itching with non-prescription antihistamines (such as diphenhydramine) to stop any residual itching.

How to treat pubic lice

  • Public lice should be treated with anti-lice agents. Treatment should be repeated after 10 days.
  • Remove nits by using a fine-toothed louse comb.
  • Examine and treat any close sexual contacts.
  • Wash and dry any bed linens and underclothes on a hot cycle.
  • Pubic lice can live on the eyebrows and eyelashes, as well as in the pubic hair. If you notice any lice or nits in these areas, apply petroleum jelly daily for up to eight days.
  • Treat itching with non-prescription antihistamines (such as diphenhydramine).
  • In the case of severe infestations, it may be helpful to shave off all the pubic hair prior to treatment with an anti-lice product.

The prevention of infestation by any of the three species of lice is best achieved through observation and avoiding practices where lice could be contracted through direct contact. Do not use anti-lice products as a preventative agent – this can cause serious health problems.

Take aways:

  • There are three kinds of lice that affect humans; head lice, body lice, and pubic lice.
  • Once a lice infestation has been experienced in a family, everyone should be checked regularly as lice infestation can recur.
  • Always practice safe sex to reduce the likelihood of catching pubic lice and other sexually transmitted diseases. Shaving the pubic hair can prevent the spread of pubic lice.
  • Washing clothing, bed linens, brushes, and combs can prevent a recurrence of a lice infestation.
  • You should not use anti-lice treatments on people who do not have a lice infestation. These products are not suitable as a preventive treatment and their use can lead to persistent itching and illness.
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Last Reviewed:
June 23, 2018
Last Updated:
June 21, 2018