Dermatophytosis, also known as tinea and ringworm, is a fungal infection of the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

(a dermatomycosis), 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. About 40 types of fungus can cause dermatophytosis. They are typically of the '' Trichophyton'', '' Microsporum'', or '' Epidermophyton'' type. Risk factors include using public showers, contact sports such as

wrestling Wrestling is a martial art, combat sport, and form of entertainment that involves grappling with an opponent and striving to obtain a position of advantage through different throws or techniques, within a given ruleset. Wrestling involves di ...

, excessive sweating, contact with animals,

obesity Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...

, and poor immune function. Ringworm can spread from other animals or between people. Diagnosis is often based on the appearance and symptoms. It may be confirmed by either culturing or looking at a skin scraping under a

microscope A microscope () is a laboratory equipment, laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic ...

. Prevention is by keeping the skin dry, not walking barefoot in public, and not sharing personal items. Treatment is typically with antifungal creams such as

clotrimazole Clotrimazole, sold under the brand name Lotrimin, among others, is an antifungal medication. It is used to treat vaginal yeast infections, oral thrush, diaper rash, tinea versicolor, and types of ringworm including athlete's foot and jock itc ...

or miconazole. If the scalp is involved, antifungals by mouth such as fluconazole may be needed. Dermatophytosis has spread globally, and up to 20% of the world's population may be infected by it at any given time. Infections of the groin are more common in males, while infections of the scalp and body occur equally in both sexes. Infections of the scalp are most common in children while infections of the groin are most common in the elderly. Descriptions of ringworm date back to

ancient history Ancient history is a time period from the History of writing, beginning of writing and recorded human history through late antiquity. The span of recorded history is roughly 5,000 years, beginning with the development of Sumerian language, ...

Types

A number of different species of fungus are involved in dermatophytosis. Dermatophytes of the genera '' Trichophyton'' and '' Microsporum'' are the most common causative agents. These fungi attack various parts of the body and lead to the conditions listed below. The Latin names are for the conditions (disease patterns), not the agents that cause them. The disease patterns below identify the type of fungus that causes them only in the cases listed: * Dermatophytosis ** Tinea pedis ( athlete's foot): fungal infection of the feet ** Tinea unguium: fungal infection of the fingernails and toenails, and the nail bed ** Tinea corporis: fungal infection of the arms, legs, and trunk ** Tinea cruris ( jock itch): fungal infection of the groin area ** Tinea manuum: fungal infection of the hands and palm area ** Tinea capitis: fungal infection of the scalp and hair ** Tinea faciei (face fungus): fungal infection of the face ** Tinea barbae: fungal infestation of facial hair * Other superficial mycoses (not classic ringworm, since not caused by dermatophytes) ** Tinea versicolor: caused by '' Malassezia furfur'' ** Tinea nigra: caused by '' Hortaea werneckii''

Signs and symptoms

Infection An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

s on the body may give rise to typical enlarging raised red rings of ringworm. Infection on the skin of the feet may cause athlete's foot and in the groin, jock itch. Involvement of the nails is termed onychomycosis. Animals including dogs and cats can also be affected by ringworm, and the disease can be transmitted between animals and humans, making it a zoonotic disease. Specific signs can be: * red, scaly, itchy or raised patches * patches may be redder on outside edges or resemble a ring * patches that begin to ooze or develop a blister * bald patches may develop when the scalp is affected

Causes

Fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

thrive in moist, warm areas, such as

locker room A locker is a small, usually narrow storage compartment. They are commonly found in dedicated cabinets, very often in large numbers, in various public places such as Changing room, locker rooms, workplaces, schools, transport hubs and the like ...

s, tanning beds,

swimming pool A swimming pool, swimming bath, wading pool, paddling pool, or simply pool, is a structure designed to hold water to enable Human swimming, swimming and associated activities. Pools can be built into the ground (in-ground pools) or built abo ...

s, and skin folds; accordingly, those that cause dermatophytosis may be spread by using exercise machines that have not been disinfected after use, or by sharing towels, clothing, footwear, or hairbrushes.

Diagnosis

Dermatophyte infections can be readily diagnosed based on the history, physical examination, and potassium hydroxide (KOH) microscopy.

Prevention

Advice often given includes: * Avoid sharing clothing, sports equipment, towels, or sheets. * Wash clothes in hot water with fungicidal soap after suspected exposure to ringworm. * Avoid walking barefoot; instead wear appropriate protective shoes in locker rooms and sandals at the beach. * Avoid touching pets with bald spots, as they are often carriers of the fungus.

Vaccination

no approved human vaccine exist against dermatophytosis. For

horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 milli ...

, dogs and

cats The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

there is available an approved inactivated vaccine called ''Insol Dermatophyton'' (

Boehringer Ingelheim C.H. Boehringer Sohn AG & Co. is the parent company of the Boehringer Ingelheim group, which was founded in 1885 by Albert Boehringer (1861–1939) in Ingelheim am Rhein, Germany. As of 2018, Boehringer Ingelheim is one of the world's List of la ...

) which provides time-limited protection against several trichophyton and microsporum fungal strains. With cattle, systemic vaccination has achieved effective control of ringworm. Since 1979 a Russian live vaccine (LFT 130) and later on a Czechoslovak live vaccine against bovine ringworm has been used. In Scandinavian countries vaccination programmes against ringworm are used as a preventive measure to improve the hide quality. In Russia, fur-bearing animals (silver fox, foxes, polar foxes) and rabbits have also been treated with vaccines.

Treatment

Antifungal treatments include topical agents such as miconazole,

terbinafine Terbinafine, sold under the brand name Lamisil among others, is an antifungal medication used to treat pityriasis versicolor, onychomycosis, fungal nail infections, and ringworm including jock itch and athlete's foot. It is either oral adminis ...

ketoconazole Ketoconazole, sold under the brand name Nizoral, among others, is an antiandrogen, antifungal drug, antifungal, and antiglucocorticoid medication used to treat a number of fungal infections. Applied to the skin it is used for fungal skin inf ...

, or tolnaftate applied twice daily until symptoms resolve — usually within one or two weeks. Topical treatments should then be continued for a further 7 days after resolution of visible symptoms to prevent recurrence. The total duration of treatment is therefore generally two weeks, but may be as long as three. In more severe cases or scalp ringworm, systemic treatment with oral medications (such as

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 ...

, and

) may be given. To prevent spreading the infection, lesions should not be touched, and good hygiene maintained with washing of hands and the body. Misdiagnosis and treatment of ringworm with a topical steroid, a standard treatment of the superficially similar pityriasis rosea, can result in tinea incognito, a condition where ringworm fungus grows without typical features, such as a distinctive raised border.

History

Dermatophytosis has been prevalent since before 1906, at which time ringworm was treated with compounds of mercury or sometimes

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

. Hairy areas of skin were considered too difficult to treat, so the

scalp The scalp is the area of the head where head hair grows. It is made up of skin, layers of connective and fibrous tissues, and the membrane of the skull. Anatomically, the scalp is part of the epicranium, a collection of structures covering th ...

was treated with

X-rays An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

and followed up with

antifungal An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as ...

medication. Another treatment from around the same time was application of Araroba powder.

Terminology

The most common term for the infection, "ringworm", is a

misnomer A misnomer is a name that is incorrectly or unsuitably applied. Misnomers often arise because something was named long before its correct nature was known, or because an earlier form of something has been replaced by a later form to which the nam ...

, since the condition is caused by

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

of several different

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

and not by parasitic worms.

Other animals

Ringworm caused by '' Trichophyton verrucosum'' is a frequent clinical condition in

cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

. Young animals are more frequently affected. The lesions are located on the head, neck, tail, and

perineum The perineum (: perineums or perinea) in placentalia, placental mammals is the space between the anus and the genitals. The human perineum is between the anus and scrotum in the male or between the anus and vulva in the female. The perineum is ...

. The typical lesion is a round, whitish crust. Multiple lesions may coalesce in "map-like" appearance. File:Toplin des dieles tiesse vea.jpg, Multiple lesions, head File:Dieles åtoû d' l' ouy åmea.JPG, Around the eyes and on ears File:2 dieles mashale.jpg, On cheeks: crusted lesion (right) File:Viye diele did près.JPG, Old lesions, with regrowing hair File:Diele vea waerot.jpg, On neck and withers File:Dieles cawî åmea.JPG, On perineum Clinical dermatophytosis is also diagnosed in

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

, dogs, cats, and

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...

s. Causative agents, besides ''Trichophyton verrucosum, are'' ''T. mentagrophytes'', ''T. equinum'', ''Microsporum gypseum'', ''M. canis'', and ''M. nanum''. Dermatophytosis may also be present in the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

eutriconodont mammal '' Spinolestes'', suggesting a

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

origin for this disease.

Diagnosis

Ringworm in pets may often be asymptomatic, resulting in a carrier condition which infects other pets. In some cases, the disease only appears when the animal develops an

immunodeficiency Immunodeficiency, also known as immunocompromise, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that aff ...

condition. Circular bare patches on the skin suggest the diagnosis, but no lesion is truly specific to the fungus. Similar patches may result from

allergies Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...

, sarcoptic mange, and other conditions. Three species of fungi cause 95% of dermatophytosis in pets: these are '' Microsporum canis'', '' Microsporum gypseum'', and '' Trichophyton mentagrophytes''.

Veterinarian A veterinarian (vet) or veterinary surgeon is a medical professional who practices veterinary medicine. They manage a wide range of health conditions and injuries in non-human animals. Along with this, veterinarians also play a role in animal r ...

s have several tests to identify ringworm infection and identify the fungal species that cause it: Woods test: This is an ultraviolet light with a magnifying lens. Only 50% of ''M. canis'' will show up as an apple-green fluorescence on hair shafts, under the UV light. The other fungi do not show. The fluorescent material is not the fungus itself (which does not fluoresce), but rather an excretory product of the fungus which sticks to hairs. Infected skin does not fluoresce. Microscopic test: The veterinarian takes hairs from around the infected area and places them in a staining solution to view under the microscope. Fungal spores may be viewed directly on hair shafts. This technique identifies a fungal infection in about 40%–70% of the infections, but cannot identify the species of dermatophyte. Culture test: This is the most effective, but also the most time-consuming, way to determine if ringworm is on a pet. In this test, the veterinarian collects hairs from the pet, or else collects fungal spores from the pet's hair with a toothbrush, or other instrument, and inoculates fungal media for culture. These cultures can be brushed with transparent tape and then read by the veterinarian using a microscope, or can be sent to a pathological lab. The three common types of fungi which commonly cause pet ringworm can be identified by their characteristic spores. These are different-appearing macroconidia in the two common species of ''Microspora'', and typical microconidia in ''Trichophyton'' infections.David W. Scott, Colour Atlas of Animal Dermatology, Blackwell Publishing Professional 2121 State Avenue, Ames, Iowa 50014, USA; ISBN 978-0-8138-0516-0/2007. Identifying the species of fungi involved in pet infections can be helpful in controlling the source of infection. ''M. canis'', despite its name, occurs more commonly in domestic cats, and 98% of cat infections are with this organism. It can also infect dogs and humans, however. ''T. mentagrophytes'' has a major reservoir in

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s, but can also infect pet

rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...

s, dogs, and horses. ''M. gypseum'' is a soil organism and is often contracted from gardens and other such places. Besides humans, it may infect rodents, dogs, cats, horses, cattle, and

swine Suina (also known as Suiformes) is a suborder of omnivorous, non-ruminant artiodactyl mammals that includes the domestic pig and peccaries. A member of this clade is known as a suine. Suina includes the family Suidae, termed suids, known in ...

Treatment

Pet animals

Treatment requires both systemic oral treatment with most of the same drugs used in humans—terbinafine, fluconazole, or itraconazole—as well as a topical "dip" therapy. Because of the usually longer hair shafts in pets compared to those of humans, the area of infection and possibly all of the longer hair of the pet must be clipped to decrease the load of fungal spores clinging to the pet's hair shafts. However, close shaving is usually not done because nicking the skin facilitates further skin infection. Twice-weekly bathing of the pet with diluted lime sulfur dip solution is effective in eradicating fungal spores. This must continue for 3 to 8 weeks. Washing of household hard surfaces with 1:10 household sodium hypochlorite bleach solution is effective in killing spores, but it is too irritating to be used directly on hair and skin. Pet hair must be rigorously removed from all household surfaces, and then the

vacuum cleaner A vacuum cleaner, also known simply as a vacuum, is a device that uses suction, and often agitation, in order to remove dirt and other debris from carpets, hard floors, and other surfaces. The dirt is collected into a dust bag or a plastic bin. ...

bag, and perhaps even the vacuum cleaner itself, discarded when this has been done repeatedly. Removal of all hair is important, since spores may survive 12 months or even as long as two years on hair clinging to surfaces.

Cattle

In bovines, an infestation is difficult to cure, as systemic treatment is uneconomical. Local treatment with

compounds is time-consuming, as it needs scraping of crusty lesions. Moreover, it must be carefully conducted using

glove A glove is a garment covering the hand, with separate sheaths or openings for each finger including the thumb. Gloves protect and comfort hands against cold or heat, damage by friction, abrasion or chemicals, and disease; or in turn to provide a ...

s, lest the worker become infested.

Epidemiology

Worldwide, superficial fungal infections caused by dermatophytes are estimated to infect around 20-25% of the population and it is thought that dermatophytes infect 10-15% of the population during their lifetime.Pires, C. A. A., Cruz, N. F. S. da, Lobato, A. M., Sousa, P. O. de, Carneiro, F. R. O., & Mendes, A. M. D. (2014). Clinical, epidemiological, and therapeutic profile of dermatophytosis. ''Anais Brasileiros de Dermatología'', ''89''(2), 259–264

/ref>Oumar Coulibaly, Coralie L'Ollivier, Renaud Piarroux, Stéphane Ranque, Epidemiology of human dermatophytoses in Africa, ''Medical Mycology'', Volume 56, Issue 2, February 2018, Pages 145–161. The highest Incidence (epidemiology), incidence of superficial mycoses result from dermatophytoses which are most prevalent in tropical regions.Rajagopalan, M., Inamadar, A., Mittal, A., Miskeen, A. K., Srinivas, C. R., Sardana, K., Godse, K., Patel, K., Rengasamy, M., Rudramurthy, S., & Dogra, S. (2018). Expert Consensus on The Management of Dermatophytosis in India (ECTODERM India). ''BMC dermatology'', ''18''(1), 6

/ref> Onychomycosis, a common infection caused by dermatophytes, is found with varying prevalence rates in many countries.Hayette, M.-P., & Sacheli, R. (2015). Dermatophytosis, Trends in Epidemiology and Diagnostic Approach. ''Current Fungal Infection Reports'', ''9''(3), 164–179

/ref> ''Tinea pedis'' + onychomycosis, ''Tinea corporis'', ''Tinea capitis'' are the most common dermatophytosis found in humans across the world. ''Tinea capitis'' has a greater prevalence in children. The increasing prevalence of dermatophytes resulting in ''Tinea capitis'' has been causing epidemics throughout Europe and America. In pets, cats are the most affected by dermatophytosis.Gordon, E., Idle, A., & DeTar, L. (2020). Descriptive epidemiology of companion animal dermatophytosis in a Canadian Pacific Northwest animal shelter system. ''The Canadian veterinary journal = La revue veterinaire canadienne'', ''61''(7), 763–770. Pets are susceptible to dermatophytoses caused by ''Microsporum canis'', ''Microsporum gypseum'', and ''Trichophyton''. For dermatophytosis in animals, risk factors depend on age, species, breed, underlying conditions, stress, grooming, and injuries. Numerous studies have found ''Tinea capitis'' to be the most prevalent dermatophyte to infect children across the continent of Africa. Dermatophytosis has been found to be most prevalent in children ages 4 to 11, infecting more males than females. Low

socioeconomic status Socioeconomic status (SES) is a measurement used by economics, economists and sociology, sociologsts. The measurement combines a person's work experience and their or their family's access to economic resources and social position in relation t ...

was found to be a risk factor for ''Tinea capitis''. Throughout Africa, dermatophytoses are common in hot- humid climates and with areas of overpopulation. Chronicity is a common outcome for dermatophytosis in India. The prevalence of dermatophytosis in India is between 36.6 and 78.4% depending on the area, clinical subtype, and dermatophyte isolate. Individuals ages 21–40 years are most commonly affected. A 2002 study looking at 445 samples of dermatophytes in patients in Goiânia, Brazil found the most prevalent type to be '' Trichophyton rubrum'' (49.4%), followed by ''Trichophyton mentagrophytes'' (30.8%), and ''Microsporum canis'' (12.6%). A 2013 study looking at 5,175 samples of ''Tinea'' in patients in Tehran, Iran found the most prevalent type to be ''Tinea pedis'' (43.4%), followed by ''Tinea unguium''. (21.3%), and ''Tinea cruris'' (20.7%).Rezaei-Matehkolaei, A., Makimura, K., de Hoog, S., Shidfar, M. R., Zaini, F., Eshraghian, M., Naghan, P. A., & Mirhendi, H. (2013). Molecular epidemiology of dermatophytosis in Tehran, Iran, a clinical and microbial survey. ''Medical Mycology (Oxford)'', ''51''(2), 203–207

/ref>

References

External links

Tinea photo library at Dermnet
{{Authority control Zoonoses Animal fungal diseases Mycosis-related cutaneous conditions Cat diseases Wikipedia emergency medicine articles ready to translate Wikipedia medicine articles ready to translate

Types

Signs and symptoms

Causes

Diagnosis

Prevention

Vaccination

Treatment

History

Terminology

Other animals

Diagnosis

Treatment

Pet animals

Cattle

Epidemiology

See also

References

Further reading

External links