Pediculosis and Pediculosis and Phthiriasis Phthiriasis Pediculus humanus capitis ( head Pediculus humanus capitis ( head lice) lice) Pediculus humanus corporis (body Pediculus humanus corporis (body lice) lice) Phthirus pubis (pubic lice) Phthirus pubis (pubic lice)
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Pediculosis and PhthiriasisPediculosis and Phthiriasis
Pediculus humanus capitis Pediculus humanus capitis
( head lice)( head lice)
Pediculus humanus corporis Pediculus humanus corporis
Head lice are most commonly found in Head lice are most commonly found in school children, with the most vulnerable school children, with the most vulnerable age being 4-11 years oldage being 4-11 years old
No significant sex differencesNo significant sex differences Do not discriminate rich or poor Do not discriminate rich or poor Do not have any preference towards dirty Do not have any preference towards dirty
or cleanor clean
PrevalencePrevalence Pediculosis has a worldwide distributionPediculosis has a worldwide distribution In epidemiologic school surveys in different In epidemiologic school surveys in different
countries found to be :countries found to be : 15% in France (Combescot, 1990),15% in France (Combescot, 1990), 33.7% in Australia (Speare and Buettner, 1999),33.7% in Australia (Speare and Buettner, 1999), 40% in Taiwan (Fan et al., 1991) 40% in Taiwan (Fan et al., 1991) 28.3% in the U.K. (Downs et al., 2000)28.3% in the U.K. (Downs et al., 2000) USA : has risen steadily over the last 3 decades USA : has risen steadily over the last 3 decades
(Guenther, L, Medscape)(Guenther, L, Medscape)
MorphologyMorphology and life cycle and life cycle Fam : Pediculidae, Fam : Pediculidae,
ordo : Anoplura ordo : Anoplura
Class : InsectaClass : Insecta Consist of head, thorax and abdomenConsist of head, thorax and abdomen 3 pair of legs, with claw (to 3 pair of legs, with claw (to cling to and cling to and
crawl through human hair) , wingless crawl through human hair) , wingless
A permanent ecto-A permanent ecto-
parasiteparasite blood-sucking insects blood-sucking insects Die after 10 days Die after 10 days
starvationstarvation Incomplete Incomplete
metamorphosismetamorphosis
Eggs : laid at the base of hairs, about ½ -Eggs : laid at the base of hairs, about ½ -inch from the scalpinch from the scalp
A female louse can lay as many as 5 - 6 A female louse can lay as many as 5 - 6 eggs each day (50-100 eggs in its lifetime)eggs each day (50-100 eggs in its lifetime)
The eggs attach to the human hair with a The eggs attach to the human hair with a material like super gluematerial like super glue
Eggs hatch after 7-10 days. Eggs hatch after 7-10 days.
Morphology and habitatMorphology and habitat
P.humanus P.humanus capitiscapitis
P.humanus P.humanus corporiscorporis
Phthirus pubisPhthirus pubis
Live on Live on human hairhuman hair
clothing and clothing and beddingbedding
Pubic hair, eye Pubic hair, eye lash, moustache lash, moustache and beard and and beard and armpitarmpit
Difficult to differentiate: Difficult to differentiate: muscle of the thorax of muscle of the thorax of P. P. humanus corporishumanus corporis clearly clearly seenseen
Rounded body Rounded body (crab louse)(crab louse)
(play role as (play role as vector of vector of epidemic epidemic typhustyphus, trench fevertrench fever, louse borne louse borne relapsing relapsing fever)fever)
• Itching/ Itching/ pruritus pruritus
at pubic areaat pubic area• eggs on eye eggs on eye lash can disturb lash can disturb eye visioneye vision
Body lice : bedding should be Body lice : bedding should be fumigatedfumigated
Pubic lice : as recommended for head Pubic lice : as recommended for head licelice
EpidemiologyEpidemiology Transferred from person to person Transferred from person to person
through comb, mats, bedding through comb, mats, bedding Phthirus pubisPhthirus pubis : : sexual activitysexual activity P.humanus corporisP.humanus corporis : mostly in : mostly in
cool climate; poor personal cool climate; poor personal hygiene hygiene