Editing Pediculosis (section)

==Head lice==
{{Main|Pediculosis capitis}}

===Presentation===
[[File:Head louse crawling on hairbrush.webm|thumb|upright=1.3|Head louse crawling on a hairbrush]]
[[File:Pediculus humanus capitis 2.jpg|thumb|upright=1.3|Phthiriasis in the head of a 6-year-old boy caused by phthiriasis pubis as confirmed by optical (c) and electron microscopy (d).<ref>{{cite book |doi=10.5772/61850 |isbn=978-953-51-2252-4 |chapter=Observation of Fungi, Bacteria, and Parasites in Clinical Skin Samples Using Scanning Electron Microscopy | vauthors = Yuping R |title=Modern Electron Microscopy in Physical and Life Sciences |editor=Janecek, Milos |editor2=Kral, Robert |publisher=InTech |year=2016|s2cid=53472683 }}</ref><!-- This is content from a predatory publisher (intechopen.com); recommend finding an alternative source for a comparable image. -->]]
Head-lice infestation is most frequent on children aged 3–10 and their families. The [[Centers for Disease Control and Prevention|CDC]] estimates that 6 to 12 million children aged 3 to 11 get lice every year.<ref name="o377">{{cite web |last=Passarella |first=Elizabeth |date=2024-02-27 |title=What to Do When Your Child Has Head Lice |url=https://www.nytimes.com/article/lice-symptoms-causes-treatment.html |access-date=2024-11-19 |website=The New York Times}}</ref> Females aged 3–12 years are most commonly infested.<ref name="Ko 2017"/> Those of African descent rarely experience infestation due to differences in hair texture.<ref name="Ko 2017">{{cite book| vauthors = Ko C, Elson DM | veditors = Tyring SK, Lupi O, Hengge UR |title=Tropical Dermatology|date=2016|publisher=Elsevier Inc|isbn=978-0-323-296342|page=387|edition=2nd|chapter=Chapter 30. Pediculosis}}</ref>

Head lice are spread through direct head-to-head contact with an infested person. From each egg or "nit" may hatch one nymph that will grow and develop to the adult louse. Lice feed on blood once or more often each day by piercing the skin with their tiny needle-like mouthparts. While feeding they excrete saliva, which irritates the skin and causes itching.<ref name="Leung">{{cite journal |vauthors=Leung AK, Robson LM |date=May 1, 2008 |title=Pruritus in Children: What's Itching? |url=http://www.consultant360.com/articles/pruritus-children-what-s-itching-0 |journal=Consultant for Pediatricians}}</ref> Lice cannot burrow into the skin.{{citation needed|date=June 2021}}

===Diagnosis===
To diagnose infestation, the entire scalp should be combed thoroughly with a louse comb and the teeth of the comb should be examined for the presence of living lice after each time the comb passes through the hair. The use of a louse comb is the most effective way to detect living lice.<ref name="PedDerm">{{cite journal | vauthors = Mumcuoglu KY, Friger M, Ioffe-Uspensky I, Ben-Ishai F, Miller J | title = Louse comb versus direct visual examination for the diagnosis of head louse infestations | journal = Pediatric Dermatology | volume = 18 | issue = 1 | pages = 9–12 | year = 2001 | pmid = 11207962 | doi = 10.1046/j.1525-1470.2001.018001009.x | s2cid = 27464495 }}</ref>

The most characteristic symptom of infestation is [[pruritus]] (itching) on the head that normally intensifies 3 to 4 weeks after the initial infestation. The bite reaction is very mild and it can be rarely seen between the hairs. Excessive scratching of the infested areas can cause sores, which may become infected.{{citation needed|date=June 2021}}

===Treatment===
The number of diagnosed cases of human louse infestations (or pediculosis) has increased worldwide since the mid-1960s, reaching hundreds of millions annually.<ref name="Gratz">{{cite web | vauthors = Gratz N | title =Human lice, their prevalence and resistance to insecticides | publisher =[[World Health Organization|World Health Organization (WHO)]] | location =[[Geneva]] | year =1998 | url = https://apps.who.int/iris/bitstream/handle/10665/63791/WHO_CTD_WHOPES_97.8.pdf }}</ref>  There is no product or method that assures 100% destruction of the eggs and hatched lice after a single treatment.  However, there are a number of treatment methods that can be employed with varying degrees of success. These methods include chemical treatments, natural products, combs, shaving, hot air, silicone-based lotions, and ethanol (ethyl alcohol).<ref>[[Ethanol]] (ethyl alcohol, common alcohol) is toxic to arthropods including lice. It can be mixed with the everyday hair conditioner for a treatment.
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{{cite book | vauthors = Marriott JF |year=2010 |title=Pharmaceutical Compounding and Dispensing |page=77 |publisher=Pharmaceutical Press |url= https://books.google.com/books?id=J5vE3Z_ZXJcC&q=lice&pg=PA77 |quote=ALCOHOL. After water, this is probably the next most important solvent used pharmaceutically. Although ethanol (ethyl alcohol) is rarely used as a lone solvent for preparations for internal use, it is used in the manufacture of some of the galenicals used in pharmacy (e.g. tinctures, see Chapter 2). In extemporaneous dispensing it is normally used for the production of lotions for external application to unbroken skin. It is particularly useful if rapid evaporation is required (e.g. for insecticidal lotions applied to hair for the treatment of lice).|isbn=9780853699125}}
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Ethanol as an arthropod killing solution. {{cite journal | vauthors = Szinwelski N, Fialho VS, Yotoko KS, Seleme LR, Sperber CF | title = Ethanol fuel improves arthropod capture in pitfall traps and preserves DNA | journal = ZooKeys | issue = 196 | pages = 11–22 | year = 2012 | pmid = 22679388 | pmc = 3361084 | doi = 10.3897/zookeys.196.3130 | quote = It has been shown that at concentrations higher than 95%, commercial alcohol preserves DNA (Nagy 2010), but the use of highly concentrated commercial alcohol as a killing solution may be prohibitively expensive when needed in large quantities, such as in large-scale biodiversity sampling. In Brazil, for example, it is illegal to carry large amounts of commercial alcohol on long journeys, which could hinder its use in extensive field expeditions. Here we propose the use of ethanol fuel as a cheaper and logistically feasible alternative | doi-access = free }}
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Pediculosis is commonly treated with [[permethrin]] lotion.<ref>{{cite journal | vauthors = Gunning K, Pippitt K, Kiraly B, Sayler M | title = Pediculosis and scabies: treatment update | journal = American Family Physician | volume = 86 | issue = 6 | pages = 535–541 | date = September 2012 | pmid = 23062045 | url = https://www.aafp.org/afp/2012/0915/p535.pdf }}</ref><ref>{{cite journal | vauthors = Verma P, Namdeo C | title = Treatment of Pediculosis Capitis | journal = Indian Journal of Dermatology | volume = 60 | issue = 3 | pages = 238–247 | date = 2015 | pmid = 26120148 | pmc = 4458933 | doi = 10.4103/0019-5154.156339 | doi-access = free }}</ref> [[Food and Drug Administration|FDA]]-approved products include permethrin for children 2 months and older, [[ivermectin]] (Sklice) for age 6 months and older, and pyrethrins for age two and older. These products should be applied twice, a week or so apart. Occlusive agents like [[petrolatum]] ([[Vaseline]]) can kill lice but are not well-studied. Combing with a fine-tooth metal comb is the only way to remove eggs, repeating every two to three days for 2 weeks.<ref name="o3772">{{cite web |last=Passarella |first=Elizabeth |date=2024-02-27 |title=What to Do When Your Child Has Head Lice |url=https://www.nytimes.com/article/lice-symptoms-causes-treatment.html |access-date=2024-11-19 |website=The New York Times}}</ref>

===Epidemiology===
About 14 million people, mainly children, are treated annually for head lice in the United States alone. Only a small proportion of those treated, however, may have objective evidence of an extant infestation.<ref name="pmid=10959734">{{cite journal | vauthors = Pollack RJ, Kiszewski AE, Spielman A | title = Overdiagnosis and consequent mismanagement of head louse infestations in North America | journal = The Pediatric Infectious Disease Journal | volume = 19 | issue = 8 | pages = 689–93; discussion 694 | date = August 2000 | pmid = 10959734 | doi = 10.1097/00006454-200008000-00003 | s2cid = 2557006 }}</ref> High levels of louse infestations have also been reported from all over the world including Denmark, Sweden, U.K., France and Australia.<ref name="pmid14651472">{{cite journal | vauthors = Burgess IF | title = Human lice and their control | journal = Annual Review of Entomology | volume = 49 | pages = 457–481 | date = January 2004 | pmid = 14651472 | doi = 10.1146/annurev.ento.49.061802.123253 | publisher = [[Annual Reviews (publisher)|Annual Reviews]] | s2cid = 21144817 }}</ref><ref name="JDD">{{cite journal | vauthors = Mumcuoglu KY, Barker SC, Burgess IE, Combescot-Lang C, Dalgleish RC, Larsen KS, Miller J, Roberts RJ, Taylan-Ozkan A | display-authors = 6 | title = International guidelines for effective control of head louse infestations | journal = Journal of Drugs in Dermatology | volume = 6 | issue = 4 | pages = 409–414 | date = April 2007 | pmid = 17668538 }}</ref>
Normally head lice infest a new host only by close contact between individuals, making social contacts among children and parent child interactions more likely routes of infestation than shared combs, brushes, towels, clothing, beds or closets. Head-to-head contact is by far the most common route of lice transmission.{{citation needed|date=June 2021}}

The United Kingdom's National Health Service, and many American health agencies,<ref>{{cite web |url=http://www.nyc.gov/html/doh/html/cd/cdped.shtml |title=Lice (Pediculosis) - What are lice? |access-date=2007-07-08 |url-status=dead |archive-url=https://web.archive.org/web/20070708233440/http://www.nyc.gov/html/doh/html/cd/cdped.shtml |archive-date=2007-07-08 }}</ref><ref>[http://www.nhs.uk/conditions/head-lice/Pages/Introduction.aspx Head lice and nits - NHS Choices]. Nhs.uk (2016-05-17). Retrieved on 2016-10-14.</ref> report that lice "prefer" clean hair, because it's easier to attach eggs and to cling to the strands.{{citation needed|date=June 2021}}

[[Head lice]] (''Pediculus humanus capitis'') are not known to be [[Vector (epidemiology)|vectors]] of diseases, unlike body lice (''Pediculus humanus humanus''), which are known vectors of epidemic or [[louse-borne typhus]] (''Rickettsia prowazekii''), [[trench fever]] (''Rochalimaea quintana'') and [[louse-borne relapsing fever]] (''Borrelia recurrentis'').{{cn|date=April 2023}}