Tinea capitis
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Tinea capitis (also known as "herpes tonsurans", "ringworm of the hair", "ringworm of the scalp", "scalp ringworm", and "tinea tonsurans") is a cutaneous
fungal A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...
infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...
(
dermatophytosis Dermatophytosis, also known as ringworm, is a fungal infection of the skin. Typically it results in a red, itchy, scaly, circular rash. Hair loss may occur in the area affected. Symptoms begin four to fourteen days after exposure. Multiple a ...
) of the
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 ...
. The disease is primarily caused by
dermatophytes Dermatophyte (from Greek '' derma'' "skin" (GEN ''dermatos'') and ''phyton'' "plant") is a common label for a group of fungus of ''Arthrodermataceae'' that commonly causes skin disease in animals and humans. Traditionally, these anamorphic (as ...
in the genera ''
Trichophyton ''Trichophyton'' is a genus of fungi, which includes the parasitic varieties that cause tinea, including athlete's foot, ringworm, jock itch, and similar infections of the nail, beard, skin and scalp. Trichophyton fungi are molds characterize ...
'' and ''
Microsporum ''Microsporum'' is a genus of fungi that causes tinea capitis, tinea corporis, ringworm, and other dermatophytoses (fungal infections of the skin). ''Microsporum'' forms both macroconidia (large asexual reproductive structures) and microconi ...
'' that invade the hair shaft. The clinical presentation is typically single or multiple patches of hair loss, sometimes with a 'black dot' pattern (often with broken-off hairs), that may be accompanied by inflammation, scaling, pustules, and itching. Uncommon in adults, tinea capitis is predominantly seen in pre-
pubertal Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. ...
children, more often boys than girls. At least eight species of dermatophytes are associated with tinea capitis. Cases of ''Trichophyton'' infection predominate from Central America to the United States and in parts of Western Europe. Infections from ''Microsporum'' species are mainly in South America, Southern and Central Europe, Africa and the Middle East. The disease is infectious and can be transmitted by humans, animals, or objects that harbor the fungus. The fungus can also exist in a carrier state on the scalp, without clinical symptomatology. Treatment of tinea capitis requires an oral antifungal agent;
griseofulvin Griseofulvin is an antifungal medication used to treat a number of types of dermatophytoses (ringworm). This includes fungal infections of the nails and scalp, as well as the skin when antifungal creams have not worked. It is taken by mouth. C ...
is the most commonly used drug, but other newer antimycotic drugs, such as
terbinafine Terbinafine, sold under the brand name Lamisil among others, is an antifungal medication used to treat pityriasis versicolor, fungal nail infections, and ringworm including jock itch and athlete's foot. It is either taken by mouth or applied to ...
,
itraconazole Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis. It may be given by mouth ...
, and
fluconazole Fluconazole is an antifungal medication used for a number of fungal infections. This includes candidiasis, blastomycosis, coccidiodomycosis, cryptococcosis, histoplasmosis, dermatophytosis, and pityriasis versicolor. It is also used to prevent ...
have started to gain acceptance.


Symptoms

It may appear as thickened, scaly, and sometimes boggy swellings, or as expanding raised red rings (
ringworm Dermatophytosis, also known as ringworm, is a fungal infection of the skin. Typically it results in a red, itchy, scaly, circular rash. Hair loss may occur in the area affected. Symptoms begin four to fourteen days after exposure. Multiple a ...
). Common symptoms are severe
itching Itch (also known as pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of sensory experience. Itch has many similarities to pain, and while both are unpleasan ...
of the scalp,
dandruff Dandruff is a skin condition that mainly affects the scalp. Symptoms include flaking and sometimes mild itchiness. It can result in social or self-esteem problems. A more severe form of the condition, which includes inflammation of the skin, ...
, and
bald Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarrin ...
patches where the fungus has rooted itself in the skin. It often presents identically to dandruff or seborrheic dermatitis. The highest incidence in the United States of America is in American boys of school age. There are three type of tinea capitis,
microsporosis ''Trichophyton'' is a genus of fungi, which includes the parasitic varieties that cause tinea, including athlete's foot, ringworm, jock itch, and similar infections of the nail, beard, skin and scalp. Trichophyton fungi are molds characterized ...
, trichophytosis, and
favus Favus (Latin for " honeycomb") or tinea favosa is the severe form of tinea capitis, a skin infectious disease caused by the dermatophyte fungus ''Trichophyton schoenleinii.'' Typically the species affects the scalp, but occasionally occurs as ...
; these are based on the causative microorganism, and the nature of the symptoms. In ''microsporosis'', the lesion is a small red
papule A papule is a small, well-defined bump in the skin. It may have a rounded, pointed or flat top, and may have a dip. It can appear with a stalk, be thread-like or look warty. It can be soft or firm and its surface may be rough or smooth. Some h ...
around a hair shaft that later becomes scaly; eventually the hairs break off 1–3 mm above the scalp. This disease used to be caused primarily by ''
Microsporum audouinii ''Microsporum audouinii'' is an anthropophilic fungus in the genus ''Microsporum''. It is a type of dermatophyte that colonizes keratinized tissues (primarily hair) causing infection. The fungus is characterized by its spindle-shaped macroconidia ...
'', but in Europe, ''M. canis'' is more frequently the causative fungus. The source of this fungus is typically sick cats and kittens; it may be spread through person to person contact, or by sharing contaminated brushes and combs. In the United States, ''Trichophytosis'' is usually caused by ''
Trichophyton tonsurans ''Trichophyton tonsurans'' is a fungus in the family Arthrodermataceae that causes ringworm infection of the scalp. It was first recognized by David Gruby in 1844. Isolates are characterized as the "–" or negative mating type of the '' Arthrode ...
'', while ''T. violaceum'' is more common in Eastern Europe, Africa, and India. This fungus causes dry, non-inflammatory patches that tend to be angular in shape. When the hairs break off at the opening of the follicle, black dots remain. ''Favus'' is caused by ''T. schoenleinii'', and is endemic in South Africa and the Middle East. It is characterized by a number of yellowish, circular, cup-shaped crusts (
scutula ''Scutula'' is a genus of lichenicolous fungi in the family Ramalinaceae. Taxonomy The genus ''Scutula'' was circumscribed by French botanist Louis René Étienne Tulasne in 1862. The limits of the generic circumscription as well as the limit ...
) grouped in patches like a piece of honeycomb, each about the size of a split pea, with a hair projecting in the center. These increase in size and become crusted over, so that the characteristic lesion can only be seen around the edge of the scab.


Pathophysiology

From the site of inoculation, the fungus grows down into the
stratum corneum The stratum corneum (Latin for 'horny layer') is the outermost layer of the epidermis. The human stratum corneum comprises several levels of flattened corneocytes that are divided into two layers: the ''stratum disjunctum'' and ''stratum compact ...
, where it invades keratin. Dermatophytes are unique in that they produce keratinase, which enables them to use keratin as a nutrient source. Infected hairs become brittle, and after three weeks, the clinical presentation of broken hairs is evident. There are three types of infection: Ectothrix: Characterized by the growth of fungal spores (
arthroconidia Arthroconidia are a type of fungal spore typically produced by segmentation of pre-existing fungal hyphae. Background These spores are asexual and are generally not as durable and environmentally persistent as, for instance, bacterial endospores ...
) on the exterior of the hair shaft.  Infected hairs usually fluoresce greenish-yellow under a Wood lamp (blacklight). Associated with ''
Microsporum canis ''Microsporum canis'' is a pathogenic, asexual fungus in the phylum Ascomycota that infects the upper, dead layers of skin on domesticated cats, and occasionally dogs and humans. The species has a worldwide distribution. Taxonomy and evolution ...
'', '' Microsporum gypseum'', ''
Trichophyton equinum ''Trichophyton'' is a genus of fungi, which includes the parasitic varieties that cause tinea, including athlete's foot, ringworm, jock itch, and similar infections of the nail, beard, skin and scalp. Trichophyton fungi are molds characterized ...
'', and ''
Trichophyton verrucosum ''Trichophyton verrucosum'', commonly known as the cattle ringworm fungus, is a dermatophyte largely responsible for fungal skin disease in cattle, but is also a common cause of ringworm in donkeys, dogs, goat, sheep, and horses. It has a worldw ...
''. Endothrix: Similar to ectothrix, but characterized by arthroconidia restricted to the hair shaft, and restricted to anthropophilic bacteria.  The cuticle of the hair remains intact and clinically this type does not have fluorescence.  Associated with ''
Trichophyton tonsurans ''Trichophyton tonsurans'' is a fungus in the family Arthrodermataceae that causes ringworm infection of the scalp. It was first recognized by David Gruby in 1844. Isolates are characterized as the "–" or negative mating type of the '' Arthrode ...
'' and ''
Trichophyton violaceum ''Trichophyton'' is a genus of fungi, which includes the parasitic varieties that cause tinea, including athlete's foot, ringworm, jock itch, and similar infections of the nail, beard, skin and scalp. Trichophyton fungi are molds characterized ...
'', which are anthropophilic. Favus: Causes crusting on the surface of the skin, combined with hair loss.  Associated with '' Trichophyton schoenleini''.


Diagnosis

Tinea capitis may be difficult to distinguish from other skin diseases that cause scaling, such as
psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to complete ...
and
seborrhoeic dermatitis Seborrhoeic dermatitis, sometimes inaccurately referred to as seborrhoea, is a long-term skin disorder. Symptoms include red, scaly, greasy, itchy, and inflamed skin. Areas of the skin rich in oil-producing glands are often affected including the ...
; the basis for the diagnosis is positive microscopic examination and microbial culture of epilated hairs.
Wood's lamp A blacklight, also called a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave (UV-A) ultraviolet light and very little visible light. One type of lamp has a violet filter material, either on the bulb or in a separat ...
examination will reveal bright green to yellow-green fluorescence of hairs infected by ''M. canis'', ''M. audouinii'', ''M. rivalieri'', and ''M. ferrugineum'' and a dull green or blue-white color of hairs infected by ''T. schoenleinii''. Individuals with ''M. canis'' infection
trichoscopy Trichoscopy is a method of hair and scalp evaluation and is used for diagnosing hair and scalp diseases. The method is based on dermoscopy. In trichoscopy hair and scalp structures may be visualized at many-fold magnification. Currently magnificat ...
will show characteristic small comma hairs. Histopathology of scalp biopsy shows fungi sparsely distributed in the stratum corneum and hyphae extending down the hair follicle, placed on the surface of the hair shaft. These findings are occasionally associated with inflammatory tissue reaction in the local tissue.


Treatment

The treatment of choice by dermatologists is a safe and inexpensive oral medication,
griseofulvin Griseofulvin is an antifungal medication used to treat a number of types of dermatophytoses (ringworm). This includes fungal infections of the nails and scalp, as well as the skin when antifungal creams have not worked. It is taken by mouth. C ...
, a secondary metabolite of the fungus ''Penicillium griseofulvin''. This compound is ''fungistatic'' (inhibiting the growth or reproduction of fungi) and works by affecting the microtubular system of fungi, interfering with the
mitotic spindle In cell biology, the spindle apparatus refers to the cytoskeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells. It is referred to as the mitotic spindle during mitosis, a pr ...
and cytoplasmic
microtubules Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27  nm and have an inner diameter between 11 an ...
. The recommended pediatric dosage is 10 mg/kg/day for 6–8 weeks, although this may be increased to 20 mg/kg/d for those infected by ''T. tonsurans'', or those who fail to respond to the initial 6 weeks of treatment. Unlike other fungal skin infections that may be treated with
topical A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...
therapies like creams applied directly to the affected area, griseofulvin must be taken orally to be effective; this allows the drug to penetrate the hair shaft where the fungus lives. The effective therapy rate of this treatment is generally high, in the range of 88–100%. Other oral antifungal treatments for tinea capitis also frequently reported in the literature include
terbinafine Terbinafine, sold under the brand name Lamisil among others, is an antifungal medication used to treat pityriasis versicolor, fungal nail infections, and ringworm including jock itch and athlete's foot. It is either taken by mouth or applied to ...
,
itraconazole Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis. It may be given by mouth ...
, and
fluconazole Fluconazole is an antifungal medication used for a number of fungal infections. This includes candidiasis, blastomycosis, coccidiodomycosis, cryptococcosis, histoplasmosis, dermatophytosis, and pityriasis versicolor. It is also used to prevent ...
; these drugs have the advantage of shorter treatment durations than griseofulvin. A 2016 meta-analysis of randomized controlled trials found that terbinafine, itraconazole and fluconazole were at least equally effective as griseofulvin for children infected with ''Trichophyton'', and terbinafine is more effective than griseofulvin for children with ''T. tonsurans'' infection''.'' However, concerns have been raised about the possibility of rare side effects like liver toxicity or interactions with other drugs; furthermore, the newer drug treatments tend to be more expensive than griseofulvin. On September 28, 2007, the U.S.
Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
stated that Lamisil (
Terbinafine Terbinafine, sold under the brand name Lamisil among others, is an antifungal medication used to treat pityriasis versicolor, fungal nail infections, and ringworm including jock itch and athlete's foot. It is either taken by mouth or applied to ...
hydrochloride, by
Novartis AG Novartis AG is a Swiss-American multinational pharmaceutical corporation based in Basel, Switzerland and Cambridge, Massachusetts, United States (global research).name="novartis.com">https://www.novartis.com/research-development/research-loca ...
) is a new treatment approved for use by
children A child ( : children) is a human being between the stages of birth and puberty, or between the developmental period of infancy and puberty. The legal definition of ''child'' generally refers to a minor, otherwise known as a person younger ...
aged 4 years and older. The antifungal granules can be sprinkled on a child's food to treat the infection. Lamisil carries hepatotoxic risk, and can cause a metallic taste in the mouth.


Epidemiology

Tinea capitis caused by species of ''
Microsporum ''Microsporum'' is a genus of fungi that causes tinea capitis, tinea corporis, ringworm, and other dermatophytoses (fungal infections of the skin). ''Microsporum'' forms both macroconidia (large asexual reproductive structures) and microconi ...
'' and ''
Trichophyton ''Trichophyton'' is a genus of fungi, which includes the parasitic varieties that cause tinea, including athlete's foot, ringworm, jock itch, and similar infections of the nail, beard, skin and scalp. Trichophyton fungi are molds characterize ...
'' is a contagious disease that is
endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
in many countries. Affecting primarily pre-
pubertal Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. ...
children between 6 and 10 years, it is more common in males than females; rarely does the disease persist past age sixteen. Because spread is thought to occur through direct contact with affected individuals, large outbreaks have been known to occur in schools and other places where children are in close quarters; however, indirect spread through contamination with infected objects (''
fomites A fomite () or fomes () is any inanimate object that, when contaminated with or exposed to infectious agents (such as pathogenic bacteria, viruses or fungi), can transfer disease to a new host. Transfer of pathogens by fomites A fomite is any inan ...
'') may also be a factor in the spread of infection. In the US, tinea capitis is thought to occur in 3-8% of the pediatric population; up to one-third of households with contact with an infected person may harbor the disease without showing any symptoms.Richardson, pp. 83–84. The fungal species responsible for causing tinea capitis vary according to the geographical region, and may also change over time. For example, ''
Microsporum audouinii ''Microsporum audouinii'' is an anthropophilic fungus in the genus ''Microsporum''. It is a type of dermatophyte that colonizes keratinized tissues (primarily hair) causing infection. The fungus is characterized by its spindle-shaped macroconidia ...
'' was the predominant
etiological Etiology (pronounced ; alternatively: aetiology or ætiology) is the study of causation or origination. The word is derived from the Greek (''aitiología'') "giving a reason for" (, ''aitía'', "cause"); and ('' -logía''). More completely, e ...
agent in North America and Europe until the 1950s, but now ''
Trichophyton tonsurans ''Trichophyton tonsurans'' is a fungus in the family Arthrodermataceae that causes ringworm infection of the scalp. It was first recognized by David Gruby in 1844. Isolates are characterized as the "–" or negative mating type of the '' Arthrode ...
'' is more common in the US, and becoming more common in Europe and the United Kingdom. This shift is thought to be due to the widespread use of griseofulvin, which is more effective against ''M. audounii'' than ''T. tonsurans''; also, changes in immigration patterns and increases in international travel have likely spread ''T. tonsurans'' to new areas.Richardson, p. 84. Another fungal species that has increased in prevalence is ''
Trichophyton violaceum ''Trichophyton'' is a genus of fungi, which includes the parasitic varieties that cause tinea, including athlete's foot, ringworm, jock itch, and similar infections of the nail, beard, skin and scalp. Trichophyton fungi are molds characterized ...
'', especially in urban populations of the United Kingdom and Europe.


See also

*
List of cutaneous conditions Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against t ...
* Ringworm affair


Footnotes


References

*


External links

{{DEFAULTSORT:Tinea Capitis Animal fungal diseases Mycosis-related cutaneous conditions Hair diseases Scalp