Body lice: Difference between revisions

	WikiDoc Resources for Body lice
Articles
Most recent articles on Body lice Most cited articles on Body lice Review articles on Body lice Articles on Body lice in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Body lice Images of Body lice Photos of Body lice Podcasts & MP3s on Body lice Videos on Body lice
Evidence Based Medicine
Cochrane Collaboration on Body lice Bandolier on Body lice TRIP on Body lice
Clinical Trials
Ongoing Trials on Body lice at Clinical Trials.gov Trial results on Body lice Clinical Trials on Body lice at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Body lice NICE Guidance on Body lice NHS PRODIGY Guidance FDA on Body lice CDC on Body lice
Books
Books on Body lice
News
Body lice in the news Be alerted to news on Body lice News trends on Body lice
Commentary
Blogs on Body lice
Definitions
Definitions of Body lice
Patient Resources / Community
Patient resources on Body lice Discussion groups on Body lice Patient Handouts on Body lice Directions to Hospitals Treating Body lice Risk calculators and risk factors for Body lice
Healthcare Provider Resources
Symptoms of Body lice Causes & Risk Factors for Body lice Diagnostic studies for Body lice Treatment of Body lice
Continuing Medical Education (CME)
CME Programs on Body lice
International
Body lice en Espanol Body lice en Francais
Business
Body lice in the Marketplace Patents on Body lice
Experimental / Informatics
List of terms related to Body lice

VisualWikitext

Revision as of 14:17, 3 December 2012

Template:DiseaseDisorder infobox

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Synonyms and keywords: Pediculosis

Overview

Body lice are parasitic insects that live on the body and in the clothing or bedding of infested humans. Body lice frequently lay their eggs on or near the seams of clothing and must feed on blood and usually only move to the skin to feed. They exist worldwide and infest people of all races.

Pathophysiology

Pathogenesis

The life cycle of the body louse Pediculus humanus humanus, has three stages: egg, nymph, and adult.

Nits are body lice eggs. They are hard to see and are often confused for dandruff. Nits are laid by the adult female and are cemented at the base of the hair shaft nearest the skin . They are 0.8 mm by 0.3 mm, oval and usually yellow to white.
Nits take about 1 week to hatch (range 6 to 9 days). Viable eggs are usually located within 6 mm of the skin.
The egg hatches to release a nymph.
The nit shell then becomes a more visible dull yellow and remains attached to the hair shaft. The nymph looks like an adult body louse, but is about the size of a pinhead.
Nymphs mature after three molts and become adults about 7 days after hatching.
The adult louse is about the size of a sesame seed, has 6 legs (each with claws), and is tan to grayish-white . In persons with dark hair, the adult louse will appear darker. Females are usually larger than males and can lay up to 8 nits per day. Adult lice can live up to 30 days on a person’s body.
To live, adult lice need to feed on blood several times daily. Without blood meals, the louse will die within 1 to 2 days off the host.

Epidemiology and Demographics

Body lice infestation is found worldwide but generally is limited to persons who live under conditions of crowding and poor hygiene who do not have access to regular bathing and changes of clean clothes, such as:

the homeless
refugees
survivors of war or natural disasters

Diagnosis

By looking closely in the seams of clothing and on the body for eggs and for crawling lice. Diagnosis should be made by a health care provider if you are unsure about infestation.

History and Symptoms

Itching and rash are common; both are your body's allergic reaction to the lice bite. Long-term body lice infestations may lead to thickening and discoloration of the skin, particularly around the waist, groin, and upper thighs. Sores on the body may be caused by scratching. These sores can sometimes become infected with bacteria or fungi.

Treatment

Lice infestations are generally treated by giving the infested person a clean change of clothes, a shower, and by laundering all worn clothing, bed linens, and towels. When laundering items, use the hot cycle (130°F) of the washing machine. Set the dryer to the hot cycle to dry items. Additionally, a 1% permethrin or pyrethrin lice shampoo, (also called pediculicide peh-DICK-you-luh-side), may be applied to the body. Medication should be applied exactly as directed on the bottle or by your physician.

References

Acknowledgements

The content on this page was first contributed by: C. Michael Gibson, M.S., M.D.

Template:WS

@@ Line 20: / Line 20: @@
 ==Pathophysiology==
-'''Etiologic agent'''
+===Pathogenesis===
-Pediculus humanus humanus (the body louse) is indistinguishable in appearance from Pediculus humanus capitus (the head louse) and under laboratory conditions they will interbreed. In their natural state, however, the two subspecies do not interbreed and occupy different habitats. In particular, body lice have evolved to attach their eggs to clothes, whereas head lice attach their eggs to the base of hairs.
+The life cycle of the body louse ''Pediculus humanus humanus'', has three stages: egg, nymph, and adult.
-Body lice are a nuisance in themselves and cause intense itching. They are however, also vectors (transmitters) of other diseases such as epidemic typhus.
+# '''Nits''' are body lice eggs. They are hard to see and are often confused for dandruff. Nits are laid by the adult female and are cemented at the base of the hair shaft nearest the skin . They are 0.8 mm by 0.3 mm, oval and usually yellow to white.
+# Nits take about 1 week to hatch (range 6 to 9 days). Viable eggs are usually located within 6 mm of the skin.
-Epidemics of typhus and louse-borne relapsing fever have been caused by body lice. Though typhus is no longer widespread, epidemics still occur during times of war, civil unrest, natural disasters, in refugee camps, and prisons where people live crowded together in unsanitary conditions. Typhus still exists in places where climate, chronic poverty, and social customs prevent regular changes and laundering of clothing.
+# The egg hatches to release a '''nymph'''.
+# The nit shell then becomes a more visible dull yellow and remains attached to the hair shaft. The nymph looks like an adult body louse, but is about the size of a pinhead.
-'''Pathophysiology'''
+# Nymphs mature after three [[molts]] and become adults about 7 days after hatching.
+# The '''adult''' louse is about the size of a sesame seed, has 6 legs (each with claws), and is tan to grayish-white . In persons with dark hair, the adult louse will appear darker. Females are usually larger than males and can lay up to 8 nits per day. Adult lice can live up to 30 days on a person’s body.
-There are three forms of body lice: the egg (sometimes called a nit), the nymph, and the adult.
+# To live, adult lice need to feed on blood several times daily. Without blood meals, the louse will die within 1 to 2 days off the host.
-'''Nit:''' Nits are body lice eggs. They are generally easy to see in the seams of clothing, particularly around the waistline and under armpits. They are about the size of the mark at the end of this arrow . Nits may also be attached to body hair. They are oval and usually yellow to white. Nits may take 30 days to hatch.
-'''Nymph:''' The egg hatches into a baby louse called a nymph. It looks like an adult body louse, but is smaller. Nymphs mature into adults about 7 days after hatching. To live, the nymph must feed on blood.
-'''Adult:''' The adult body louse is about the size of a sesame seed, has 6 legs, and is tan to greyish-white. Females lay eggs. To live, adult lice need to feed on blood. If the louse falls off of a person, it dies within 10 days.
 == Epidemiology and Demographics ==