* The incidence of pubic lice worldwide is estimated at 2,000 per 100,000 cases.<ref name="pmid24825336">{{cite journal |vauthors=Dholakia S, Buckler J, Jeans JP, Pillai A, Eagles N, Dholakia S |title=Pubic lice: an endangered species? |journal=Sex Transm Dis |volume=41 |issue=6 |pages=388–91 |year=2014 |pmid=24825336 |doi=10.1097/OLQ.0000000000000142 |url=}}</ref><ref name="pmid12671547">{{cite journal |vauthors=Varela JA, Otero L, Espinosa E, Sánchez C, Junquera ML, Vázquez F |title=Phthirus pubis in a sexually transmitted diseases unit: a study of 14 years |journal=Sex Transm Dis |volume=30 |issue=4 |pages=292–6 |year=2003 |pmid=12671547 |doi= |url=}}</ref>
* Accurate numbers are difficult to acquire, because pubic lice infestations are not considered a reportable condition by many governments, and many cases are self-treated or treated discreetly by personal physicians.<ref>{{cite journal |author=Alice L. Anderson & Elizabeth Chaney |year=2009 |title=Pubic lice (''Pthirus pubis''): history, biology and treatment vs. knowledge and beliefs of US College students |journal=[[International Journal of Environmental Research and Public Health]] |volume=6 |issue=2 |pages=592–600 |pmid=19440402 |pmc=2672365 |doi=10.3390/ijerph6020592 |url=http://www.mdpi.com/1660-4601/6/2/592}}</ref>
* It has recently been suggested that an increasing percentage of humans [[Body grooming|removing]] their [[pubic hair]] has led to reduced crab louse populations in some parts of the world.<ref>{{cite journal |author=N. R. Armstrong & J. D. Wilson |year=2006 |title=Did the "Brazilian" kill the pubic louse? |journal=[[Sexually Transmitted Infections (journal)|Sexually Transmitted Infections]] |volume=82 |pages=265–266 |doi=10.1136/sti.2005.018671 |pmid=16731684 |pmc=2564756}}</ref><ref>Bloomberg: [http://www.bloomberg.com/news/2013-01-13/brazilian-bikini-waxes-make-crab-lice-endangered-species-health.html Brazilian bikini waxes make crab lice endangered species], published 13 January 2013, retrieved 14 January 2013</ref>
==Risk Factors==
==Risk Factors==
==Natural History, Complications and Prognosis==
==Natural History, Complications and Prognosis==
==Screening==
There are no screening recommendations for pubic lice. <ref name= "USPSTF"> U.S. Preventive Services Task Force https://www.uspreventiveservicestaskforce.org/BrowseRec/Search?s=pubic+lice </ref>
==History and Symptoms==
==History and Symptoms==
* Although any part of the [[body]] may be colonized, crab lice favor the [[hairs]] of the [[Genital area|genital]] and peri-anal region. Especially in male patients, pubic lice and eggs can also be found in [[hair]] on the [[abdomen]] and under the [[armpits]] as well as on the beard and mustache, while in children they are usually found in [[eyelashes]]. Infestation with pubic lice is called ''Phthiriasis'' or ''Pediculosis pubis'', while infestation of [[eyelashes]] with pubic lice is called ''Phthriasis palpebrarum'' <ref>Manjunatha NP, Jayamanne GR, Desai SP, Moss TR, Lalik J, Woodland A. Pediculosis pubis: presentation to ophthalmologist as pthriasis palpebrarum associated with corneal epithelial keratitis. Int. J. STD AIDS 2006; 17: 424-426</ref>.
* The main symptom is [[itching]], usually in the [[pubic hair]] area. It results from [[hypersensitivity]] to [[louse]] [[saliva]], and it becomes strong enough 2 or more weeks following initial infestation.<ref name="pmid24825336">{{cite journal |vauthors=Dholakia S, Buckler J, Jeans JP, Pillai A, Eagles N, Dholakia S |title=Pubic lice: an endangered species? |journal=Sex Transm Dis |volume=41 |issue=6 |pages=388–91 |year=2014 |pmid=24825336 |doi=10.1097/OLQ.0000000000000142 |url=}}</ref>
* [[Erythematous]] sore lesions may be seen due to scratching.<ref name="pmid24825336">{{cite journal |vauthors=Dholakia S, Buckler J, Jeans JP, Pillai A, Eagles N, Dholakia S |title=Pubic lice: an endangered species? |journal=Sex Transm Dis |volume=41 |issue=6 |pages=388–91 |year=2014 |pmid=24825336 |doi=10.1097/OLQ.0000000000000142 |url=}}</ref>
* In the majority of infestations, a characteristic grey-blue or slate coloration appears (maculae caeruleae) at the feeding site, which may last for days and is also characteristic for the infestation.
==Physical Examination==
==Physical Examination==
[[Skin]] examination in patients with pubic lice may reveal the following findings:<ref name="Mandell">{{cite book |last=Bennett |first=John E. |last2=Dolin |first2=Raphael |last3=Blaser |first3=Martin J. |date= 2015 |title=Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases |url= |location= |publisher=Elsevier Inc. |page= |isbn=978-1-4557-4801-3 |author-link= }}</ref>
* Visualization of the pubic lice and their nits in the [[Pubic|pubic area]]. Other sites that may be affected include the perianal and [[Inguinal region|inguinal areas]], [[axillary]] and [[chest]] hair, as well as the [[eyelashes]].
* [[Papules|Papular]] [[urticaria]]
* [[Excoriation|Excoriations]], which may become secondarily infected
* Maculae cerulea: a pathognomonic finding for pubic lice. These are blue-gray, irregularly shaped [[macules]], which measure 0.5-1 cm in diameter and are usually scattered over the lower [[abdomen]], [[buttocks]] and upper [[thighs]].
* [[Inguinal]] [[lymphadenopathy]]
<gallery>
Image:Fig._1._Pubic_lice_in_genital_area.jpg|Fig.1 Pubic lice in genital area
Image:Fig._2._Pubic_lice_in_abdomen.jpg|Fig.2 Pubic lice in abdomen
Image:Fig._3._Pubic_lice_on_eye-lashes.jpg|Fig.3 Pubic lice on eye-lashes
</gallery>
==Laboratory Findings==
==Laboratory Findings==
The diagnosis of pubic lice is made by visualization of [[lice]] on [[pubic hair]] and there are no laboratory findings associated with pubic lice.<ref name="pmid23062045">{{cite journal |vauthors=Gunning K, Pippitt K, Kiraly B, Sayler M |title=Pediculosis and scabies: treatment update |journal=Am Fam Physician |volume=86 |issue=6 |pages=535–41 |year=2012 |pmid=23062045 |doi= |url=}}</ref>
==Other Diagnostic Studies==
==Other Diagnostic Studies==
Diagnosis of pediculosis pubis is made through direct visualization of the lice on [[pubic hair]].<ref name="pmid23062045">{{cite journal |vauthors=Gunning K, Pippitt K, Kiraly B, Sayler M |title=Pediculosis and scabies: treatment update |journal=Am Fam Physician |volume=86 |issue=6 |pages=535–41 |year=2012 |pmid=23062045 |doi= |url=}}</ref>
==Medical Therapy==
==Medical Therapy==
==Medical Therapy==
*Generally, all patients with Pediculosis pubis require [[Antimicrobial drug|antimicrobial therapy]].
*Randomized clinical data that compares the efficacy and safety of [[Antimicrobial drug|antimicrobial therapies]] is scarce.
*The majority of trials that evaluate therapies for Pediculosis pubis are based on the management of head lice.<ref name="pmid2420284">{{cite journal| author=Meinking TL, Taplin D, Kalter DC, Eberle MW| title=Comparative efficacy of treatments for pediculosis capitis infestations. | journal=Arch Dermatol | year= 1986 | volume= 122 | issue= 3 | pages= 267-71 | pmid=2420284 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2420284 }} </ref><ref name="pmid7997000">{{cite journal| author=Chosidow O, Chastang C, Brue C, Bouvet E, Izri M, Monteny N et al.| title=Controlled study of malathion and d-phenothrin lotions for Pediculus humanus var capitis-infested schoolchildren. | journal=Lancet | year= 1994 | volume= 344 | issue= 8939-8940 | pages= 1724-7 | pmid=7997000 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7997000 }} </ref><ref name="pmid9045056">{{cite journal| author=Parker J| title=Treatment of head lice. | journal=N Engl J Med | year= 1997 | volume= 336 | issue= 10 | pages= 734-5; author reply 735 | pmid=9045056 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9045056 }} </ref><ref name="pmid20220184">{{cite journal| author=Chosidow O, Giraudeau B, Cottrell J, Izri A, Hofmann R, Mann SG et al.| title=Oral ivermectin versus malathion lotion for difficult-to-treat head lice. | journal=N Engl J Med | year= 2010 | volume= 362 | issue= 10 | pages= 896-905 | pmid=20220184 | doi=10.1056/NEJMoa0905471 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20220184 }} </ref>
* '''Phthirus pubis therapy'''<ref>{{Cite journal| issn = 1545-8601| volume = 64| issue = RR-03| pages = 1–137| last1 = Workowski| first1 = Kimberly A.| last2 = Bolan| first2 = Gail A.| title = Sexually transmitted diseases treatment guidelines, 2015| journal = MMWR. Recommendations and reports: Morbidity and mortality weekly report. Recommendations and reports / Centers for Disease Control| date = 2015-06-05| pmid = 26042815}}</ref><ref name="pmid21680662">{{cite journal| author=Scott GR, Chosidow O, IUSTI/WHO| title=European guideline for the management of pediculosis pubis, 2010. | journal=Int J STD AIDS | year= 2011 | volume= 22 | issue= 6 | pages= 304-5 | pmid=21680662 | doi=10.1258/ijsa.2011.011114 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21680662 }} </ref>
:* '''Preferred regimen (1):''' [[Permethrin]] 1% cream rinse applied to affected areas and washed off after 10 minutes
:* '''Alternative regimen (1):''' [[Malathion]] 0.5% lotion applied to affected areas and washed off after 8–12 hours
:*'''Alternative regimen (2):''' [[Phenothrin]] 0.2% lotion applied to affected areas and washed off after 2 hours
:* '''Alternative regimen (3):''' [[Ivermectin]] 250 ug/kg PO, may be repeated in 1-2 weeks
:* '''Note (1):''' If [[Malathion]] or [[Phenothrin]] lotion is to be applied to hair, the hair should be dry. In contrast, [[Permethrin]] should be applied to wet hair.
:* '''Note (2):''' If necessary, treatment may be repeated after 1 week.
:* '''Note (3):''' [[Permethrin]] may be safe among pregnant women, but randomized data is lacking.<ref name="pmid17439567">{{cite journal| author=Mytton OT, McGready R, Lee SJ, Roberts CH, Ashley EA, Carrara VI et al.| title=Safety of benzyl benzoate lotion and permethrin in pregnancy: a retrospective matched cohort study. | journal=BJOG | year= 2007 | volume= 114 | issue= 5 | pages= 582-7 | pmid=17439567 | doi=10.1111/j.1471-0528.2007.01290.x | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17439567 }} </ref>
===Specific Considerations===
==== Eyelashes ====
==== If the eyelashes are infected, the following are indicated:<ref name="pmid21680662">{{cite journal| author=Scott GR, Chosidow O, IUSTI/WHO| title=European guideline for the management of pediculosis pubis, 2010. | journal=Int J STD AIDS | year= 2011 | volume= 22 | issue= 6 | pages= 304-5 | pmid=21680662 | doi=10.1258/ijsa.2011.011114 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21680662 }} </ref> ====
::* '''Preferred regimen:''' [[Permethrin]] 1% lotion to be applied using a cotton swab to the eyelashes and to be washed out after 10 minutes
::* '''Alternative regimen:''' [[Ivermectin]] 250 ug/kg PO, may be repeated in 1-2 weeks
::Note: Keep eyelids closed during application of [[Permethrin]]
::**Vaseline eye patch may be reapplied twice per day for 8-10 days
::**Use tweezers (or forceps) to remove visible lice
===Non-Pharmacologic Management===
*Clothes should be decontaminated by laundering at temperatures > 50 C.<ref name="pmid2444166">{{cite journal| author=Kalter DC, Sperber J, Rosen T, Matarasso S| title=Treatment of pediculosis pubis. Clinical comparison of efficacy and tolerance of 1% lindane shampoo vs 1% permethrin creme rinse. | journal=Arch Dermatol | year= 1987 | volume= 123 | issue= 10 | pages= 1315-9 | pmid=2444166 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2444166 }} </ref><ref name="pmid21680662">{{cite journal| author=Scott GR, Chosidow O, IUSTI/WHO| title=European guideline for the management of pediculosis pubis, 2010. | journal=Int J STD AIDS | year= 2011 | volume= 22 | issue= 6 | pages= 304-5 | pmid=21680662 | doi=10.1258/ijsa.2011.011114 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21680662 }} </ref>
===Treatment of Sexual Partners===
*Pubic lice may be spread through [[Sex (activity)|sexual intercourse]].
*Therefore, all partners with whom the patient has had sexual contact within the previous 30 days should be evaluated and treated, and sexual contact should be avoided until all partners have successfully completed treatment and are thought to be cured.<ref name="pmid21680662">{{cite journal| author=Scott GR, Chosidow O, IUSTI/WHO| title=European guideline for the management of pediculosis pubis, 2010. | journal=Int J STD AIDS | year= 2011 | volume= 22 | issue= 6 | pages= 304-5 | pmid=21680662 | doi=10.1258/ijsa.2011.011114 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21680662 }} </ref>
*Because of the strong association between the presence of pubic lice and other [[Sexually transmitted infections|sexually transmitted infections (STIs)]], patients diagnosed with pubic lice should undergo evaluation for other [[Sexually transmitted disease|STIs]].<ref name="pmid21680662">{{cite journal| author=Scott GR, Chosidow O, IUSTI/WHO| title=European guideline for the management of pediculosis pubis, 2010. | journal=Int J STD AIDS | year= 2011 | volume= 22 | issue= 6 | pages= 304-5 | pmid=21680662 | doi=10.1258/ijsa.2011.011114 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21680662 }} </ref>
==Surgery==
==Surgery==
There is no role for surgery in the treatment of pubic lice.
Pediculosis pubis was reported in the literature as early as 1946.[1]
In 1946, Andrew G. Franks describes the use of DDT in the treatment of pediculosis pubis.[1]
Classification
Infestation with pubic lice may be classified according to the site affected into:[2]
Phthiriasis pubis: infestation of pubic hair with pubic lice
Phthiriasis palpebrarum: infestation of eyelashes with pubic lice
Pathophysiology
Transmission
Pubic lice are usually acquired by intimate contact between individuals.[3] Parent-to-child infestations are more likely to occur through routes of shared towels, clothing, beds or closets. Adults are more frequently infested than children. As with most sexually transmitted pathogens, they can only survive a short time away from the warmth and humidity of the human body. Infection in a young child is not necessarily indicative of sexual abuse, although this possibility should be kept in mind.[4][5]
Life Cycle
Pubic lice (Phthirus pubis) have three stages: egg, nymph and adult. Eggs (nits) are laid on a hair shaft. Females will lay approximately 30 eggs during their 3–4 week life span. Eggs hatch after about a week and become nymphs, which look like smaller versions of the adults. The nymphs undergo three molts before becoming adults. Adults are 1.5–2.0 mm long and flattened. They are much broader in comparison to head and body lice. Adult lice are found only on the human host and require humanblood to survive. If adults are forced off the host, they will die within 24–48 hours without a blood feeding. Pubic lice are transmitted from person to person most-commonly via sexual contact, although fomites (bedding, clothing) may play a minor role in their transmission.
Pubic Lice life cycle
Macroscopic Characteristics
Pubic lice have three forms: the egg (also called a nit), the nymph, and the adult.
Nit: Nits are lice eggs. They can be hard to see and are found firmly attached to the hair shaft. They are oval and usually yellow to white.
Nymph: The nymph is an immature louse that hatches from the nit (egg). A nymph looks like an adult pubic louse but it is smaller. To live, a nymph must feed on blood. It takes 2–3 weeks after hatching to mature into adults capable of reproducing.
Adult: The adult pubic louse resembles a miniature crab when viewed through a strong magnifying glass. Pubic lice have six legs; their two front legs are very large and look like the pincher claws of a crab. This is how they got the nickname "crabs." Pubic lice are tan to grayish-white in color. Females lay nits and are usually larger than males. To live, lice must feed on blood. If the louse falls off a person, it dies within 1–2 days.[3]
Causes
The cause of pubic lice is pediculus pubis. For more information about the microorganism, click here.
Differentiating Pediculosis pubis from other Diseases
Pediculosis pubis must be differentiated from:[6][7][8]
presents with white/cream-colored soft nodules or gelatinous sheaths along the hair shaft. It can be easily detached from the hair
Caused by Trichosporon, a superficial fungal infection on the hair shaft
Wet mount of the nodules with 10-15% KOH is diagnostic (visualized hyphae)
Epidemiology and Demographics
Risk Factors
Natural History, Complications and Prognosis
History and Symptoms
Physical Examination
Laboratory Findings
Other Diagnostic Studies
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
References
↑ 1.01.1FRANKS AG, DOBES WL (1946). "DDT in the treatment of scabies, larva migrans and pediculosis pubis". Arch Derm Syphilol. 53: 381. PMID21026349.
↑N. P. Manjunatha, G. R. Jayamanne, S. P. Desai, T. R. Moss, J. Lalik & A. Woodland (2006). "Pediculosis pubis: presentation to ophthalmologist as pthriasis palpebrarum associated with corneal epithelial keratitis". International Journal of STD & AIDS. 17 (6): 424–426. doi:10.1258/095646206777323445.CS1 maint: Multiple names: authors list (link)
