Kerion

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Kerion
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Kerion

Kerion or kerion celsi is an acute inflammatory process which is the result of the host's response to a fungal ringworm infection of the hair follicles of the scalp (occasionally the beard) that can be accompanied by secondary bacterial infection(s). It usually appears as raised, spongy lesions, and typically occurs in children. [1] This honeycomb is a painful inflammatory reaction with deep suppurative lesions on the scalp. Follicles may be seen discharging pus. There may be sinus formation and rarely mycetoma-like grains are produced. It is usually caused by dermatophytes (fungal infections of the skin affecting humans and animals) such as Trichophyton verrucosum , T. mentagrophytes , [1] and Microsporum canis . Treatment with oral griseofulvin common. [1]

Contents

Symptoms and signs

There may be loss of hair as hair will come out easily. [2] Sometimes, there is growth of organisms. [3] Lymph and fever symptoms may be present. This condition can be mistaken for a case of impetigo. [4]

Diagnosis

The basis for the diagnosis of kerion is clinical finding, positive microscopic examinations (such as positive KOH preparation, Lactophenol cotton blue wet mount, Chicago sky blue stained (CSB) slide, Calcofluor white stained slide, Periodic acid–Schiff stained slide, and Gomori’s methenamine silver stained slide), mycological culture and modern molecular tests (such as PCR-reverse line blot test, real-time PCR test, multiplex PCR test, PCR-ELISA test, and MALDI-TOF test) of clinical specimens. Wood's lamp (blacklight) examination will reveal a bright green to yellow-green fluorescence of hairs infected by Trichophyton mentagrophytes var. Mentagrophytes, in kerion infection caused by Trichophyton verrucosum Invaded hairs show an ectothrix infection and fluorescence under Wood's ultra-violet light has been noted in cattle but not in humans.[ citation needed ]

Differential Diagnosis

Kerion has been called a great mimicker. [5] It can be easily confused with bacterial scalp abscess and various other conditions.

In a recent report, a previously well 9-year-old boy presented to the outpatients’ clinic with a tender, swollen occipital scalp lesion progressing over one month’s duration. He was initially misdiagnosed as having a bacterial infection, and was given a 2 weeks’ course of oral cephalexin. [5] No improvement was noticed after the course.[ citation needed ]

It was only after the scalp scrapings were examined, that the child was found to be having a local infection with the fungus Trichophyton tonsurans , which had resulted in kerion. [5] Antifungal therapy was then started, which resulted in complete cure.[ citation needed ]

Treatment

Unlike most other manifestations of Tinea dermatophyte infections, Kerion is not sufficiently treated with topical antifungals and requires systemic therapy. Typical therapy consists of oral antifungals, such as griseofulvin or terbinafine, for a sustained duration of at least 6 to 8 weeks depending on severity. Successful treatment of kerion often requires empiric bacterial antibiotics given the high prevalence of secondary bacterial infection. [6]

See also

Related Research Articles

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<span class="mw-page-title-main">Griseofulvin</span> Antifungal medication used for dermatophytoses

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<span class="mw-page-title-main">Tinea corporis</span> Medical condition

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<span class="mw-page-title-main">Tinea capitis</span> Cutaneous fungal infection of the scalp

Tinea capitis is a cutaneous fungal infection (dermatophytosis) of the scalp. The disease is primarily caused by dermatophytes in the genera Trichophyton and Microsporum that invade the hair shaft. The clinical presentation is typically single or multiple patches of hair loss, sometimes with a 'black dot' pattern, that may be accompanied by inflammation, scaling, pustules, and itching. Uncommon in adults, tinea capitis is predominantly seen in pre-pubertal children, more often boys than girls.

<span class="mw-page-title-main">Tinea barbae</span> Medical condition

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<span class="mw-page-title-main">Dermatophytosis</span> Fungal infection of the skin

Dermatophytosis, also known as tinea and ringworm, is a fungal infection of the skin, that may affect skin, hair, and nails. 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. The types of dermatophytosis are typically named for area of the body that they affect. Multiple areas can be affected at a given time.

<span class="mw-page-title-main">KOH test</span> Test to differentiate between skin fungi

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<i>Trichophyton rubrum</i> Species of fungus

Trichophyton rubrum is a dermatophytic fungus in the phylum Ascomycota. It is an exclusively clonal, anthropophilic saprotroph that colonizes the upper layers of dead skin, and is the most common cause of athlete's foot, fungal infection of nail, jock itch, and ringworm worldwide. Trichophyton rubrum was first described by Malmsten in 1845 and is currently considered to be a complex of species that comprises multiple, geographically patterned morphotypes, several of which have been formally described as distinct taxa, including T. raubitschekii, T. gourvilii, T. megninii and T. soudanense.

<i>Trichophyton</i> Genus of Fungi

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 by the development of both smooth-walled macro- and microconidia. Macroconidia are mostly borne laterally directly on the hyphae or on short pedicels, and are thin- or thick-walled, clavate to fusiform, and range from 4 to 8 by 8 to 50 μm in size. Macroconidia are few or absent in many species. Microconidia are spherical, pyriform to clavate or of irregular shape, and range from 2 to 3 by 2 to 4 μm in size.

<i>Microsporum audouinii</i> Species of fungus

Microsporum audouinii is an anthropophilic fungus in the genus Microsporum. It is a type of dermatophyte that colonizes keratinized tissues causing infection. The fungus is characterized by its spindle-shaped macroconidia, clavate microconidia as well as its pitted or spiny external walls.

<i>Trichophyton tonsurans</i> Species of fungus

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 Arthroderma vanbreuseghemii complex. This species is thought to be conspecific with T. equinum, although the latter represents the "+" mating strain of the same biological species Despite their biological conspecificity, clones of the two mating types appear to have undergone evolutionary divergence with isolates of the T. tonsurans-type consistently associated with Tinea capitis whereas the T. equinum-type, as its name implies, is associated with horses as a regular host. Phylogenetic relationships were established in isolates from Northern Brazil, through fingerprinting polymorphic RAPD and M13 markers. There seems to be lower genomic variability in the T. tonsurans species due to allopatric divergence. Any phenotypic density is likely due to environmental factors, not genetic characteristics of the fungus.

<span class="mw-page-title-main">Fungal folliculitis</span> Inflammation of hair follicles due to fungal infection

Majocchi's granuloma is a skin condition characterized by deep, pustular plaques, and is a form of tinea corporis. It is a localized form of fungal folliculitis. Lesions often have a pink and scaly central component with pustules or folliculocentric papules at the periphery. The name comes from Domenico Majocchi, who discovered the disorder in 1883. Majocchi was a professor of dermatology at the University of Parma and later the University of Bologna. This disease is most commonly caused by filamentous fungi in the genus Trichophyton.

<i>Microsporum gypseum</i> Species of fungus

Microsporum gypseum is a soil-associated dermatophyte that occasionally is known to colonise and infect the upper dead layers of the skin of mammals. The name refers to an asexual "form-taxon" that has been associated with four related biological species of fungi: the pathogenic taxa Arthroderma incurvatum, A. gypsea, A. fulva and the non-pathogenic saprotroph A. corniculata. More recent studies have restricted M. gypseum to two teleomorphic species A. gypseum and A. incurvatum. The conidial states of A. fulva and A. corniculata have been assigned to M. fulvum and M. boullardii. Because the anamorphic states of these fungi are so similar, they can be identified reliably only by mating. Two mating strains have been discovered, "+" and "–". The classification of this species has been based on the characteristically rough-walled, blunt, club-shaped, multicelled macroconidia. Synonyms include Achorion gypseum, Microsporum flavescens, M. scorteum, and M. xanthodes. There has been past nomenclatural confusion in the usage of the generic names Microsporum and Microsporon.

Trichophyton concentricum is an anthropophilic dermatophyte believed to be an etiological agent of a type of skin mycosis in humans, evidenced by scaly cutaneous patches on the body known as tinea imbricata. This fungus has been found mainly in the Pacific Islands and South America.

Microsporum nanum is a pathogenic fungus in the family Arthrodermataceae. It is a type of dermatophyte that causes infection in dead keratinized tissues such as skin, hair, and nails. Microsporum nanum is found worldwide and is both zoophilic and geophilic. Animals such as pigs and sheep are the natural hosts for the fungus; however, infection of humans is also possible. Majority of the human cases reported are associated with pig farming. The fungus can invade the skin of the host; if it is scratched off by the infected animal, the fungus is still capable of reproducing in soil.

<i>Microsporum gallinae</i> Species of fungus

Microsporum gallinae is a fungus of the genus Microsporum that causes dermatophytosis, commonly known as ringworm. Chickens represent the host population of Microsporum gallinae but its opportunistic nature allows it to enter other populations of fowl, mice, squirrels, cats, dogs and monkeys. Human cases of M. gallinae are rare, and usually mild, non-life-threatening superficial infections.

<span class="mw-page-title-main">Favus</span> Medical condition

Favus 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 onychomycosis, tinea barbae, or tinea corporis.

<i>Trichophyton verrucosum</i> Species of fungus

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 worldwide distribution, however human infection is more common in rural areas where contact with animals is more frequent, and can cause severe inflammation of the afflicted region. Trichophyton verrucosum was first described by Emile Bodin in 1902.

References

  1. 1 2 3 Uprety, Shraddha; Sharma, Ramesh (2016-09-08). "Kerion — A Boggy Lump". New England Journal of Medicine. 375 (10): 980. doi:10.1056/NEJMicm1514152. PMID   27602670.
  2. "Management of Tinea Capitis". The International Foundation for Dermatology. Retrieved January 21, 2015.
  3. L. C. Fuller; F. J. Child; G. Midgley; E. M. Higgins (March 8, 2003). "Diagnosis and management of scalp ringworm". BMJ. 326 (7388): 539–541. doi:10.1136/bmj.326.7388.539. PMC   1125423 . PMID   12623917.
  4. "Cause of Kerion Ringworm Scalp Condition, Kerions Treatment". Health Blurbs. Archived from the original on January 10, 2018. Retrieved January 21, 2015.
  5. 1 2 3 Rajkumar A, Britton PN (June 20, 2022). "Kerion: a great mimicker". Med J Aust. 216 (11): 563–567. doi:10.5694/mja2.51588. PMID   35644987. S2CID   249221828.
  6. "Kerion". DermNet New Zealand. Retrieved December 19, 2017.