![PHTH Pediculidae Pediculus humanus capitis](https://upload.wikimedia.org/wikipedia/commons/3/31/PHTH_Pediculidae_Pediculus_humanus_capitis.png)
The head louse (''Pediculus humanus capitis'') is an
obligate {{wiktionary, obligate
As an adjective, obligate means "by necessity" (antonym ''facultative'') and is used mainly in biology in phrases such as:
* Obligate aerobe, an organism that cannot survive without oxygen
* Obligate anaerobe, an organism that ...
ectoparasite
Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
of
human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
s.
Head lice are wingless
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s that spend their entire lives on the human
scalp
The scalp is the anatomical area bordered by the human face at the front, and by the neck at the sides and back.
Structure
The scalp is usually described as having five layers, which can conveniently be remembered as a mnemonic:
* S: The ski ...
and feeding exclusively on human
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...
.
Humans are the only known
hosts
A host is a person responsible for guests at an event or for providing hospitality during it.
Host may also refer to:
Places
*Host, Pennsylvania, a village in Berks County
People
*Jim Host (born 1937), American businessman
*Michel Host ( ...
of this specific parasite, while
chimpanzee
The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative th ...
s and
bonobos
The bonobo (; ''Pan paniscus''), also historically called the pygmy chimpanzee and less often the dwarf chimpanzee or gracile chimpanzee, is an endangered great ape and one of the two species making up the genus '' Pan,'' the other being the comm ...
host a closely related species, ''Pediculus schaeffi''. Other species of
lice
Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a result o ...
infest most orders of mammals and all orders of birds.
Lice differ from other
hematophagic
Hematophagy (sometimes spelled haematophagy or hematophagia) is the practice by certain animals of feeding on blood (from the Greek words αἷμα ' "blood" and φαγεῖν ' "to eat"). Since blood is a fluid tissue rich in nutritious pro ...
ectoparasites such as
flea
Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by ingesting the blood of their hosts. Adult fleas grow to about long, a ...
s in spending their entire lifecycle on a host.
Head lice cannot fly, and their short, stumpy legs render them incapable of jumping, or even walking efficiently on flat surfaces.
The non-disease-carrying head louse differs from the related disease-carrying
body louse
The body louse (''Pediculus humanus humanus'', also known as ''Pediculus humanus corporis'') is a hematophagic ectoparasite louse that infests humans. It is one of three lice which infest humans, the other two being the head louse, and the cr ...
(''Pediculus humanus humanus'') in preferring to attach eggs to scalp hair rather than to clothing. The two
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
are morphologically almost identical, but do not normally interbreed. From genetic studies, they are thought to have diverged as subspecies about 30,000–110,000 years ago, when many humans began to wear a significant amount of clothing.
A much more distantly related species of hair-clinging louse, the pubic or
crab louse
The crab louse or pubic louse (''Pthirus pubis'') is an insect that is an obligate ectoparasite of humans, feeding exclusively on blood. The crab louse usually is found in the person's pubic hair. Although the louse cannot jump, it can also li ...
(''Pthirus pubis''), also infests humans. It is morphologically different from the other two species and is much closer in appearance to the lice which infest other primates.
Louse infestation of the body is known as
pediculosis
Pediculosis is an infestation of lice from the sub-order Anoplura, family Pediculidae. Accordingly, the infestation with head lice is named pediculosis capitis, while this with body lice, pediculosis corporis. Although ''pediculosis'' in humans ma ...
,
pediculosis capitis
Head lice infestation, also known as pediculosis capitis, is the infection of the head hair and scalp by the head louse (''Pediculus humanus capitis''). Itching from lice bites is common. During a person's first infection, the itch may not devel ...
for head lice,
pediculosis corporis
Pediculosis corporis is a cutaneous condition caused by body lice (specifically ''Pediculus humanus humanus'') that lay their eggs in the seams of clothing.
Signs and symptoms
Body lice are a nuisance in themselves and cause intense itching. The ...
for body lice, and
phthiriasis
Pediculosis pubis (also known as "crabs" and "pubic lice") is an infestation by the pubic louse, ''Pthirus pubis'', a wingless insect which feeds on blood and lays its eggs (nits) on mainly pubic hair. Less commonly, hair near the anus, armpit ...
for pubic lice.
Head lice (especially in children) have been, and still are, subject to various eradication campaigns. Unlike body lice, head lice are not the vectors of any known diseases, however rare secondary infections can result from scratching at bites. Head louse infestations may be beneficial in helping to foster a natural
immune
In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. Immunity involves both specific and nonspecific components. The nonspecific components act as barriers or eliminators of a wide range of pathogens ...
response against lice which helps humans in defense against the far more dangerous
body louse
The body louse (''Pediculus humanus humanus'', also known as ''Pediculus humanus corporis'') is a hematophagic ectoparasite louse that infests humans. It is one of three lice which infest humans, the other two being the head louse, and the cr ...
, which is capable of transmitting dangerous diseases.
Adult morphology
Like other insects of the suborder
Anoplura
Sucking lice (Anoplura, formerly known as Siphunculata) have around 500 species and represent the smaller of the two traditional superfamily (taxonomy), superfamilies of lice. As opposed to the paraphyletic chewing lice, which are now divided amo ...
, adult head lice are small (2.5–3 mm long), dorsoventrally flattened (see
anatomical terms of location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
), and wingless.
The
thoracic
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the crea ...
segments are fused, but otherwise distinct from the
head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...
and
abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
, the latter being composed of seven visible
segments.
Head lice are grey in general, but their precise color varies according to the environment in which they were raised.
After feeding, consumed blood causes the louse body to take on a reddish color.
Head
![Pediculus humanus var capitis](https://upload.wikimedia.org/wikipedia/commons/3/32/Pediculus_humanus_var_capitis.jpg)
One pair of
antennae, each with five segments, protrudes from the insect's head. Head lice also have one pair of
eye
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conv ...
s. Eyes are present in all species within the Pediculidae family, but are reduced or absent in most other members of the Anoplura suborder.
Like other members of the Anoplura, head louse mouthparts are highly adapted for piercing the skin and sucking blood.
These mouth parts are retracted into the insect's head except during feeding.
[
]
Thorax
![Head louse on human hair](https://upload.wikimedia.org/wikipedia/commons/5/54/Head_louse_on_human_hair.jpg)
Six
legs
A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ...
project from the fused segments of the
thorax
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...
.
As is typical in the Anoplura, these legs are short and terminate with a single
claw
A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tarsus ...
and opposing "
thumb
The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thumb ...
".
Between its claw and thumb, the louse grasps the hair of its host.
With their short legs and large claws, lice are well adapted to clinging to the hair of their host. These adaptations leave them incapable of jumping, or even walking efficiently on flat surfaces. Lice can climb up strands of hair very quickly, allowing them to move quickly and reach another host.
Abdomen
Seven segments of the louse
abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
are visible.
The first six segments each have a pair of
spiracles through which the insect breathes.
The last segment contains the
anus
The anus (Latin, 'ring' or 'circle') is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, the residual semi-solid waste that remains after food digestion, which, d ...
and (separately) the
genitalia
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, a ...
.
Sex differences
In male lice, the front two legs are slightly larger than the other four. This specialized pair of legs are used for holding the female during copulation. Males are slightly smaller than females and are characterized by a pointed end of the abdomen and a well-developed genital apparatus visible inside the abdomen. Females are characterized by two gonopods in the shape of a W at the end of their abdomens.
Eggs and nits
![Head louse egg 2](https://upload.wikimedia.org/wikipedia/commons/d/d6/Head_louse_egg_2.jpg)
Like most insects, head lice are
oviparous
Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...
. Females lay about three or four eggs per day. Louse
eggs
Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...
(also known as ''nits''), are attached near the base of a host hair shaft.
Eggs are usually laid on the base of the hair, 3–5 mm off the scalp surface.
In warm climates, and especially the tropics, eggs may be laid or more down the hair shaft.
To attach an egg, the adult female secretes a glue from her reproductive organ. This glue quickly hardens into a "nit sheath" that covers the hair shaft and large parts of the egg except for the operculum, a cap through which the embryo breathes.
The glue was previously thought to be
chitin
Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chit ...
-based, but more recent studies have shown it to be made of
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
s similar to hair
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...
.
Each egg is oval-shaped and about 0.8 mm in length.
They are bright, transparent, and tan to coffee-colored so long as they contain an embryo, but appear white after hatching.
Head lice hatch typically six to nine days after
oviposition
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...
.
After hatching, the louse
nymph
A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are ty ...
leaves behind its egg shell, still attached to the hair shaft. The empty egg shell remains in place until physically removed by abrasion or the host, or until it slowly disintegrates, which may take six or more months.
Empty shells are mat, collapsed and white in color. The term ''nit'' may include any of the following:
* Viable eggs that will eventually hatch
* Remnants of already-hatched eggs (nits)
* Nonviable eggs (dead
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
) that will never hatch
Of these three, only eggs containing viable embryos have the potential to infest or reinfest a host.
However, a
no nit policy
No nit policy is a public health policy implemented by some education authorities to prevent the transmission of head lice infestation. The "no nit" policy requires the sending home and barring of all children who have nits (egg shells) on their ...
is a common public health measure to prevent transmission of lice. Some authors have therefore restricted the definition of nit to describe only a hatched or nonviable egg:
![Anoplura hatching](https://upload.wikimedia.org/wikipedia/commons/3/35/Anoplura_hatching.jpg)
Others have retained the broad definition, while simultaneously attempting to clarify its relevance to infestation:
In British and Irish slang the term "nit" is often used, across different age groups, to refer to the head lice themselves.
Development and nymphs
![Pediculus humanus development](https://upload.wikimedia.org/wikipedia/commons/7/7e/Pediculus_humanus_development.jpg)
Head lice, like other insects of the order
Phthiraptera
Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a result o ...
, are
hemimetabolous
Hemimetabolism or hemimetaboly, also called incomplete metamorphosis and paurometabolism,McGavin, George C. ''Essential Entomology: An Order-by-Order Introduction''. Oxford: Oxford University Press, 2001. pp. 20. is the mode of development of certa ...
.
Newly hatched
nymphs
A nymph ( grc, νύμφη, nýmphē, el, script=Latn, nímfi, label=Modern Greek; , ) in ancient Greek folklore is a minor female nature deity. Different from Greek goddesses, nymphs are generally regarded as personifications of nature, are typ ...
will
moult
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...
three times before reaching the sexually-mature adult stage.
Thus, mobile head lice populations may contain eggs, nits, three nymphal
instars
An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...
, and the adults (male and female) (
imago
In biology, the imago (Latin for "image") is the last stage an insect attains during its metamorphosis, its process of growth and development; it is also called the imaginal stage, the stage in which the insect attains maturity. It follows the f ...
).
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...
during head louse development is subtle. The only visible differences between different instars and the adult, other than size, is the relative length of the abdomen, which increases with each molt.
, as well as the existence of reproductive organs in the adults. Aside from reproduction, nymph behavior is similar to the adult. Like adults, nymphs feed also only on human blood (hematophagia), and cannot survive long away from a host.
Outside their hosts lice can't survive more than 24 hrs.
The time required for head lice to complete their nymph development to the imago lasts for 12-15 days.
Nymph mortality in captivity is about 38%, especially within the first two days of life.
In the wild, mortality may instead be highest in the third instar.
Nymph hazards are numerous. Failure to completely hatch from the egg is invariably fatal.
Death during molting can also occur, although it is reportedly uncommon.
During feeding, the nymph gut can rupture, dispersing the host's blood throughout the insect body. This results in death within a day or two.
Whether the high mortality recorded under experimental conditions is representative of conditions in the wild is unclear.
Reproduction and lifespan
![Nuttall 1917 f11](https://upload.wikimedia.org/wikipedia/commons/a/a5/Nuttall_1917_f11.gif)
Head lice
reproduce sexually
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote tha ...
, and
copulation
Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...
is necessary for the female to produce fertile eggs.
Parthenogenesis
Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...
, the production of viable offspring by virgin females, does not occur in ''Pediculus humanus''.
Pairing can begin within the first 10 hours of adult life.
After 24 hours, adult lice copulate frequently, with
mating
In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. ''Copulation'' is the union of the sex organs of two sexually reproduc ...
occurring during any period of the night or day.
Mating attachment frequently lasts more than an hour.
Young males can successfully pair with older females, and vice versa.
Experiments with ''P. h. humanus'' (body lice) emphasize the attendant hazards of lice copulation. A single young female confined with six or more males will die in a few days, having laid very few eggs.
Similarly, death of a virgin female was reported after admitting a male to her confinement.
The female laid only one egg after mating, and her entire body was tinged with red—a condition attributed to rupture of the
alimentary canal
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans ...
during the sexual act.
Old females frequently die following, if not during, copulation.
During its lifespan of 4 weeks a female louse lays 50-150 eggs. Eggs hatch within 6-9 days, each nymphal stage last for 4-5 days and accordingly the period from egg to adults lasts for 18-24 days. Adult lice live for an additional 3-4 weeks.
Factors affecting infestation
The number of children per family, the sharing of beds and closets, hair washing habits, local customs and social contacts, healthcare in a particular area (e.g. school), and socioeconomic status were found to be significant factors in head louse infestation. Girls are two to four times more frequently infested than boys. Children between 4 and 14 years of age are the most frequently infested group.
Behaviour
Feeding
All stages except eggs are blood-feeders and bite the skin four to five times daily to feed. They inject saliva which contains an
anticoagulant
Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where the ...
and suck blood. The digested blood is excreted as dark red
frass
Frass refers loosely to the more or less solid excreta of insects, and to certain other related matter.
Definition and etymology
''Frass'' is an informal term and accordingly it is variously used and variously defined. It is derived from the ...
.
Position on host
Although any part of the scalp may be colonized, lice favor the nape of the neck and the area behind the ears, where the eggs are usually laid. Head lice are repelled by light and move towards shadows or dark-coloured objects in their vicinity.
Transmission
Lice have no wings or powerful legs for jumping, so they move using the claws on their legs to move from hair to hair.
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, hats, brushes, towels, clothing, beds, or closets.
Head-to-head contact is by far the most common route of lice transmission.
Distribution
About 6–12 million people, mainly children, are treated annually for head lice in the United States alone. In the UK, it is estimated that two thirds of children will experience at least one case of head lice before leaving primary school. High levels of louse infestations have also been reported from all over the world, including Australia, Denmark, France, Ireland, Israel, and Sweden.
Archaeogenetics
Analysis of the DNA of lice found on
Peru
, image_flag = Flag of Peru.svg
, image_coat = Escudo nacional del Perú.svg
, other_symbol = Great Seal of the State
, other_symbol_type = Seal (emblem), National seal
, national_motto = "Fi ...
vian
mummies
A mummy is a dead human or an animal whose soft tissues and organs have been preserved by either intentional or accidental exposure to chemicals, extreme cold, very low humidity, or lack of air, so that the recovered body does not decay furth ...
may indicate that some diseases (such as
typhus
Typhus, also known as typhus fever, is a group of infectious diseases that include epidemic typhus, scrub typhus, and murine typhus. Common symptoms include fever, headache, and a rash. Typically these begin one to two weeks after exposure.
...
) may have passed from the
New World
The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 3 ...
to the
Old World
The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by the ...
, instead of the other way around.
Genome
The sequencing of the genome of the body louse was first proposed in the mid-2000s and the annotated genome was published in 2010. An analysis of the body and head louse transcriptomes revealed these two organisms are extremely similar genetically.
Mitochondrial clades
Human lice are divided into three deeply divergent mitochondrial clades known as A, B, and C.
Three subclades have been identified, D (a sister clade of A), E (a sister clade of C), and F (a sister clade of B).
Clade A
* head and body: worldwide
*found in ancient Roman Judea
Clade D (sister of clade A)
* head and body: Central Africa, Ethiopia, United States
Clade B
* head only: worldwide
* found in ancient Roman Judea and 4,000-year-old Chilean mummy
Clade F (sister of clade B)
* head and body: South America
Clade C
* head only: Ethiopia, Nepal, Thailand
Clade E (sister of clade C)
* head only: West Africa
See also
*
Body louse
The body louse (''Pediculus humanus humanus'', also known as ''Pediculus humanus corporis'') is a hematophagic ectoparasite louse that infests humans. It is one of three lice which infest humans, the other two being the head louse, and the cr ...
*
Crab louse
The crab louse or pubic louse (''Pthirus pubis'') is an insect that is an obligate ectoparasite of humans, feeding exclusively on blood. The crab louse usually is found in the person's pubic hair. Although the louse cannot jump, it can also li ...
*
Lindane
Lindane, also known as ''gamma''-hexachlorocyclohexane (γ-HCH), gammaxene, Gammallin and benzene hexachloride (BHC), is an organochlorine chemical and an isomer of hexachlorocyclohexane that has been used both as an agricultural insecticide and ...
*
List of parasites of humans
Endoparasites Protozoan organisms
Helminths (worms)
Helminth organisms (also called helminths or intestinal worms) include:
Tapeworms
Flukes
Roundworms
Other organisms
Ectoparasites
References
{{Portal bar, Bio ...
*
Nitpicking
Nitpicking is a term, first used in 1956, that describes the action of giving too much attention to unimportant detail. A person who nitpicks is termed as a nitpicker.
The terminology originates from the common act of manually removing nits (t ...
*
Pediculosis
Pediculosis is an infestation of lice from the sub-order Anoplura, family Pediculidae. Accordingly, the infestation with head lice is named pediculosis capitis, while this with body lice, pediculosis corporis. Although ''pediculosis'' in humans ma ...
*
Treatment of human head lice
The treatment of human lice is the removal of head lice parasites from human hair. It has been debated and studied for centuries. However, the number of cases of human louse infestations (or pediculosis) has increased worldwide since the mid-1960s, ...
References
External links
Centers for Disease Control and Prevention: Division of Parasitic DiseasesUniversity of Nebraska: Head Lice Resources You Can Truston the
UF /
IFAS Featured Creatures Web site
Head Louse infestations
{{Taxonbar, from=Q27358
Lice
Insects described in 1767
Parasitic arthropods of humans
Ectoparasites
Subspecies
Taxa named by Charles De Geer