The Facts Of Lice: Prevention And Treatment

By Sonia Gulati. May 7th 2016

Lice are highly contagious, diminutive, wingless parasites that feed on human blood. Lice infestations are a very common problem and afflict millions of people worldwide. Although in some cases a lice infestation may pose a significant health hazard, it is typically innocuous, and causes mainly itching and discomfort. There are three primary types of lice infestation, each caused by a different parasite and found on different parts of the body. Effective treatment regimens exist for each type of lice infestation.

Types Of Lice

  • Head lice: Head lice are the most common form of lice infestation. The head louse is a small (about the size of a sesame seed), grayish-white insect that develops on the scalp. They are most commonly found behind the ears and near the neckline at the base of the scalp. Head lice are incapable of clinging to coarser hair on the body and therefore are not found on pubic hair.
  • Body lice: Body lice infestation is a major public-health problem that usually afflicts populations that are impoverished or live in overcrowded and transitional housing. The body louse, unlike the head louse, lives within the seams of clothing and transfers to a human host to feed. The body louse can live up to thirty days away from a human host. Body lice may also transmit such diseases as epidemic typhus, trench fever, and epidemic relapsing fever.
  • Pubic lice: Pubic lice, also known as crabs, are most commonly found in the pubic and peri-anal areas, and sometimes can infest eyebrows, eyelashes, mustaches and beards. Pubic lice remain attached to the same place for a long time during blood feeding, resulting in accumulation of their feces and matting of the pubic hair.


The primary symptom of a lice infestation is intense itching. In the case of head and pubic lice, the itching usually occurs on the scalp or in the pubic area respectively. Itching associated with body lice usually occurs where clothing is tightest around the body, such as around the waistband or bra strap. Other symptoms of lice include:

  • Tickling feeling from movement of hair.
  • The appearance of small red bumps or skin discoloration (usually associated with pubic lice).
  • Finding lice or nits (eggs that lice lay) on your scalp, body, clothing, and on your hair.


Lice infestations are spread when a person comes into contact with lice. Lice are most commonly spread as a result of:

  • Prolonged person-to-person contact. While lice infestation is commonly thought of as a sign of poor hygiene, it is actually spread from contact with an affected individual.
  • Coming into contact with the belongings of infected people. Sharing such items as clothing, headphones or brushes with an infected person may promote the spread of lice. Furthermore, storing infected pillows, blankets, stuffed toys in close proximity at home can also permit lice to spread.
  • Contact with contaminated furniture. Sharing a bed with an infected person or sitting on a cloth-covered piece of furniture that a person with lice had recently sat on can promote the spread of body lice.
  • Sexual contact. Pubic lice are spread primarily via sexual contact and most commonly affect adults.


In order to detect lice, a doctor may examine you using a magnifying lens or with a Wood's light, which checks specifically for nits.

  • Head lice. A diagnosis of head lice is made when either a nit or adult louse is seen in the hair or on the scalp. Nits must be no less than ¼-inch away from the scalp.
  • Body lice. A diagnosis of body lice may be made if eggs or crawling lice are found in the seams of clothing or on bedding. It's possible to see a body louse on skin if it crawls there to feed.
  • Pubic lice. Pubic lice are diagnosed when moving lice or nits are seen on hair in the pubic area or on other areas of coarse hair, such as chest hair, eyebrows or eyelashes.

Lice Prevention And Treatment

The treatment of body lice does not require medical intervention. However, it does require that your body be washed thoroughly, along with your bed linens and clothes (which must be washed and dried in hot cycles). In contrast to body lice, head and pubic lice require medical intervention and are treated similarly. These treatments involve:

  • Over-the-counter products. Shampoos containing pyrethrin (Rid) or permethrin (Nix) are considered the first line of defense against lice infestations. In order to get optimal results, you must follow the product's directions very closely. Some products may require you to apply a second treatment 7-to-10 days after the first treatment. It may take 3-to-4 days before the itching subsides.
  • Prescription medications. Malathion and benzyl alcohol lotion are prescription medications that are applied directly to the hair and scalp. As with over the counter medications, you may be required to apply a second treatment seven days after the first treatment. Possible side effects include irritation of the skin, scalp and eyes as well as numbness at the application site.

(To learn about treating a child with a head lice infestation, see How To Remove Head Lice In Children.)

Once you have taken the appropriate steps to rid lice from your body, you must do the same for your home. Decontaminating your home involves:

  • Wash contaminated items. Such items as bedding, clothing, hats and stuffed animals should be washed in hot, soapy water and dried on high heat for at least 20 minutes.
  • Seal items that can't be washed. Place these items in an airtight bag for two weeks.
  • Vacuum the floor and furniture. Be sure to discard the vacuum bag immediately.
  • Wash combs and brushes. These items should be washed in hot water. They can also be soaked in rubbing alcohol for an hour.

While people commonly associate lice with the infestation that occurs on the scalp, there are two other forms of lice you need to be aware of. With this guide and other precautionary measures, you can effectively treat and prevent the different forms of lice.


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