What is Lice?

21:55 - 4 May , 2021


They are small hematophagous parasitic insects that live in different parts of the human body and that are easily spread through physical or sexual contact with the carrier or through their personal use objects such as clothing, towels, brushes, or caps, causing an infestation known as pediculosis.

They are classified according to the body area in which they live:

  • Scalp lice: these can be best seen on the ears and the back of the neck. Their life cycle is up to 30 days and they implant their eggs (nits), which look like dandruff, to guarantee the survival of the species.
  • Body lice: they do not live on the body, but rather on clothing or sheets, from where they move to the person’s skin to obtain food. 
  • Pubic lice: they are also known as crab lice. Its habitat is the pubic hair and skin.

It is widely believed that the presence of lice is due to a lack of personal hygiene, which is false, since it is possible to maintain proper hygiene and still suffer from lice infestation. 

It is a condition more frequent in children between the ages of four and 12, but it can affect people of any age and become a recurrent problem if it is not treated adequately to solve it, since the female louse secretes a kind of organic glue that fixes the nits in the hair, whose incubation period lasts between eight to 10 days, making it difficult to eradicate. 

Signs and symptoms Lice

  • Intense itching in the part of the body where the lice are found. 
  • Tingling and tickling by these insects’ movement. 
  • Finding live or dead lice on the head, body, genitals, or clothing.
  • Nits or eggs in the hair, neck, and ears.
  • Ulcers and scabs in the affected areas, caused mainly by scratching.

Diagnosis and treatment Lice

Your doctor will perform a physical examination to identify lice using a magnifying glass or Wood’s light, which turns lice blue.

Once the pediculosis is confirmed, and according to the degree of infestation and the affected areas, the treatment will be established:

Scalp pediculosis:

  • Shampoo or hair lotion to eliminate lice.
  • Oral antiparasitic drugs.
  • Disinfection of clothes, towels, sheets, and personal items.

Body pediculosis:

  • Take constant hot baths.
  • Apply a topical medication to the infested parts. 
  • Disinfection of clothes, towels, sheets, and personal items.

Pubic pediculosis: 

  • You must follow the same treatment indicated for scalp pediculosis.

It is not difficult to eliminate adult lice following these treatments, but the real challenge is to get rid of all the eggs or nits on the body, textiles, and bedding. 


Avoiding scalp pediculosis in children is not easy, but there are better chances of achieving it if you recommend your child not to put his or her head together with other children, not to lend or borrow clothes, hats, brushes, and accessories, and avoid leaving his or her belongings in common use places. 

In ABC Medical Center’s Internal Medicine Department, we offer health care services with the highest quality and safety, from the prevention, diagnosis, timely treatment, and monitoring of infectious, respiratory, endocrinological, dermatological, rheumatic, nephrological, gastrointestinal, and hematological pathologies of both chronic-degenerative diseases and acute conditions, through a comprehensive and multidisciplinary model.


  • elsevier.es
  • msdmanuals.com
  • mayoclinic.org
  • medlineplus.gov
  • cdc.gov
  • healthychildren.org
  • medigraphic.com
  • Valle BMA, Muñoz TA, Flores VME, et al. La pediculosis capitis en alumnos de escuelas públicas mexicanas. Rev Cubana Med Trop. 2018;70(2):1-8.
  • Carrillo IJ, Varela RJR, Almanza CJL, et al. Un curioso pero mortal cuento de piojos, pulgas y garrapatas, sacado de la triste realidad en que vivimos en el México del siglo XXI: Aprendizaje de la medicina basada en cuentos. Rev Mex Neuroci. 2014;15(5):247-250.
  • Zúñiga CIR, Caro LJ. Piojos, una ectoparasitosis emergente. Rev Enfer Infec Pediatr. 2010;23.24(94):56-63.
  • Valle-Barbosa. MA, Muñoz-de la Torre A, Vega-López MG, et al. La pediculosis en México: una historia que no concluye. Sal Jal. 2017;4(3):185-191.

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