Tinea corporis
Encyclopedia
Tinea corporis is a superficial fungal infection
(dermatophytosis
) of the arms and legs, especially on glabrous skin, however it may occur on any part of the body.
), beard area (tinea barbae
) or the groin (tinea cruris, known as jock itch or dhobi itch).
Other classic features of tinea corporis include:
. These tiny organisms normally live on the superficial skin surface, and when the opportunity is right, they can induce a rash or infection
.
The disease can also be acquired by:
Person-to-person transfer usually via direct skin contact with an infected individual. Animal-to-human transmission is also common. Recent fossil evidence suggests that early Homo sapiens
may have contracted ringworm from sharing carrion with wolves & dogs. Ringworm commonly occurs on pets (dogs, cats) and the fungus can be acquired while petting or grooming an animal. Ringworm can also be acquired from other animals like horses, pigs, ferrets and cows. The fungus can also be spread by touching inanimate objects like personal care products, bed linen, combs, athletic gear, or hair brushes contaminated by an affected person.
Individuals at high risk of acquiring ringworm include those who:
which quickly reveal the presence of a fungus. If the skin scrapings are negative and a fungus is still suspected, the scrapings are sent for culture. Because the fungus grows slowly, the culture results do take several days to become positive.
, ketoconazole
, miconazole
, terbinafine
, tolnaftate
, and butenafine
.
If there are several ringworm lesions, the lesions are extensive, complications such as secondary infection exist, or the patient is immunocompromised, oral antifungal medications can be used. Oral medications are taken once a day for 7 days and result in higher clinical cure rates. The antifungal medications most commonly used are itraconazole
and terbinafine
.
Mycosis
A mycosis is a fungal infection of animals, including humans. Mycoses are common, and a variety of environmental and physiological conditions can contribute to the development of fungal diseases...
(dermatophytosis
Dermatophytosis
Dermatophytosis or ringworm is a clinical condition caused by fungal infection of the skin in humans, pets such as cats, and domesticated animals such as sheep and cattle. The term "ringworm" is a misnomer, since the condition is caused by fungi of several different species and not by parasitic worms...
) of the arms and legs, especially on glabrous skin, however it may occur on any part of the body.
Symptoms
It may have a variety of appearances; most easily identifiable are the enlarging raised red rings with a central area of healing (ringworm). The same appearances of ringworm may also occur on the scalp (tinea capitisTinea capitis
Tinea capitis is a superficial fungal infection of the scalp. The disease is primarily caused by dermatophytes in the Trichophyton and Microsporum genera that invade the hair shaft...
), beard area (tinea barbae
Tinea barbae
Tinea barbæ is a fungal infection of the hair. Tinea barbae is due to a dermatophytic infection around the bearded area of men. Generally, the infection occurs as a follicular inflammation, or as a cutaneous granulomatous lesion, i.e. a chronic inflammatory reaction. It is one of the causes of...
) or the groin (tinea cruris, known as jock itch or dhobi itch).
Other classic features of tinea corporis include:
- The edge of the rashRashA rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
appears elevated and is scaly to touch. - Sometimes the skin surrounding the rash may be dry and flaky.
- Almost invariably, there will be hair loss in areas of the infection.
Causes
Tinea corporis is caused by a tiny fungus known as dermatophyteDermatophyte
Dermatophytes are a common label for a group of three types of fungus that commonly causes skin disease in animals and humans. These anamorphic genera are: Microsporum, Epidermophyton and Trichophyton. There are about 40 species in these three genera...
. These tiny organisms normally live on the superficial skin surface, and when the opportunity is right, they can induce a rash or infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
.
The disease can also be acquired by:
Person-to-person transfer usually via direct skin contact with an infected individual. Animal-to-human transmission is also common. Recent fossil evidence suggests that early Homo sapiens
Human
Humans are the only living species in the Homo genus...
may have contracted ringworm from sharing carrion with wolves & dogs. Ringworm commonly occurs on pets (dogs, cats) and the fungus can be acquired while petting or grooming an animal. Ringworm can also be acquired from other animals like horses, pigs, ferrets and cows. The fungus can also be spread by touching inanimate objects like personal care products, bed linen, combs, athletic gear, or hair brushes contaminated by an affected person.
Individuals at high risk of acquiring ringworm include those who:
- Live in crowded, humidHumidityHumidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...
conditions. - Sweat excessively, as sweat can produce a humid wet environment where the pathogenic fungiPathogenic fungiPathogenic fungi are fungi that cause disease in humans or other organisms. The study of pathogenic fungi is referred to as medical mycology. Although fungi are eukaryotic organisms many pathogenic fungi are also microorganisms.-Candida:...
can thrive. This is most common in the armpits, groin creases and skin folds of the abdomen. - Participate in close contact sports like soccer, rugbyRugby footballRugby football is a style of football named after Rugby School in the United Kingdom. It is seen most prominently in two current sports, rugby league and rugby union.-History:...
, or wrestlingWrestlingWrestling is a form of grappling type techniques such as clinch fighting, throws and takedowns, joint locks, pins and other grappling holds. A wrestling bout is a physical competition, between two competitors or sparring partners, who attempt to gain and maintain a superior position...
. - Wear tight, constrictive clothing with poor aeration.
- Have a weakened immune systemImmunodeficiencyImmunodeficiency is a state in which the immune system's ability to fight infectious disease is compromised or entirely absent. Immunodeficiency may also decrease cancer immunosurveillance. Most cases of immunodeficiency are acquired but some people are born with defects in their immune system,...
(e.g., those infected with HIVHIVHuman immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
or taking immunosuppressive drugImmunosuppressive drugImmunosuppressive drugs or immunosuppressive agents are drugs that inhibit or prevent activity of the immune system. They are used in immunosuppressive therapy to:...
s).
Diagnosis and testing
Once a fungus is suspected, your physician will examine the skin and take scrapings. These superficial scraps of skin are examined underneath the microscopeMicroscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
which quickly reveal the presence of a fungus. If the skin scrapings are negative and a fungus is still suspected, the scrapings are sent for culture. Because the fungus grows slowly, the culture results do take several days to become positive.
Prevention
Because fungi prefer warm, moist environments, preventing ringworm involves keeping skin dry and avoiding contact with infectious material. Basic prevention measures include:- Washing hands after handling animals, soil, and plants.
- Avoiding touching characteristic lesions on other people.
- Wearing loose-fitting clothing.
- Practicing good hygiene when participation in sports involves physical contact with other people.
Treatment
Most cases are treated by application of topical antifungal creams to the skin, but in extensive or difficult to treat cases systemic treatment with oral medication may be required.Treatment
In general ringworm responds well to topical treatment. Topical antifungals are applied to the lesion twice a day for at least 3 weeks. The lesion usually resolves within 2 weeks, but therapy should be continued for another week to ensure the fungus is completely eradicated. The most commonly used antifungal creams are clotrimazoleClotrimazole
Clotrimazole is an antifungal medication commonly used in the treatment of fungal infections such as vaginal yeast infections, oral thrush, and ringworm...
, ketoconazole
Ketoconazole
Ketoconazole is a synthetic antifungal drug used to prevent and treat fungal skin infections, especially in immunocompromised patients such as those with AIDS or those on chemotherapy. Ketoconazole is sold commercially as an anti-dandruff shampoo, topical cream, and oral tablet.Ketoconazole is...
, miconazole
Miconazole
Miconazole is an imidazole antifungal agent, developed by Janssen Pharmaceutica, commonly applied topically to the skin or to mucus membranes to cure fungal infections. It works by inhibiting the synthesis of ergosterol, a critical component of fungal cell membranes...
, terbinafine
Terbinafine
Terbinafine hydrochloride is a...
, tolnaftate
Tolnaftate
Tolnaftate is a synthetic over-the-counter anti-fungal agent. It may come as a cream, powder, spray, or liquid aerosol, and is used to treat jock itch, athlete's foot and ringworm. It is sold under several brand names, most notably Tinactin and Odor Eaters . Other brands are Absorbine, Aftate,...
, and butenafine
Butenafine
Butenafine hydrochloride is a synthetic benzylamine antifungal, marketed under the trade names Mentax, Butop and is the active ingredient in Schering-Plough's Lotrimin Ultra. It is structurally related to synthetic allylamine antifungals such as terbinafine.-Pharmacology:Butenafine hydrochloride...
.
If there are several ringworm lesions, the lesions are extensive, complications such as secondary infection exist, or the patient is immunocompromised, oral antifungal medications can be used. Oral medications are taken once a day for 7 days and result in higher clinical cure rates. The antifungal medications most commonly used are itraconazole
Itraconazole
Itraconazole , invented in 1984, is a triazole antifungal agent that is prescribed to patients with fungal infections. The drug may be given orally or intravenously.-Medical uses:...
and terbinafine
Terbinafine
Terbinafine hydrochloride is a...
.
Prognosis
Tinea corporis is very contagious and can infect everyone in the household. If a person acquires it, the proper measures must be taken to prevent its spreading. Young children in particular should be educated about the infection and how to avoid it. Because of how easily the condition passes between individuals, tinea corporis will keep recurring if preventative measures are not taken. Avoid wearing tight thick restrictive clothing; fungus thrive in warm humid conditions. If pets are kept in the household or premises, they should be checked regularly. It is recommended to get the animal checked for tinea, especially if hair loss in patches is noticed or the pet is scratching excessively. The majority of people who have acquired tinea know how uncomfortable the infection can be. However, the fungus can easily be treated and prevented in individuals with a healthy immune system.See also
- Fungal folliculitisFungal folliculitisFungal folliculitis is a skin condition characterized by a deep, pustular type of tinea circinata resembling a carbuncle or kerion....
- List of cutaneous conditions
- Tinea corporis gladiatorumTinea corporis gladiatorumTinea corporis gladiatorum is a dermatophytic infection present in wrestlers, with skin lesions typically found on the head, neck, and arms....