Athlete's foot
Encyclopedia
Athlete's foot is a fungal infection of the skin that causes scaling, flaking, and itch of affected areas. It is caused by fungi in the genus Trichophyton
and is typically transmitted in moist areas where people walk barefoot, such as showers or bathhouses. Although the condition typically affects the feet, it can spread to other areas of the body, including the groin
. Athlete's foot can be treated by a number of pharmaceutical and other treatments.
The infection can be spread to other areas of the body, such as the groin
, and usually is called by a different name once it spreads, such as tinea corporis
on the body or limbs and tinea cruris (jock itch or dhobi itch) for an infection of the groin. Tinea pedis most often manifests between the toes, with the space between the fourth and fifth digits most commonly afflicted.
Some individuals may experience an allergic response to the fungus called an "id reaction" in which blisters or vesicles can appear in areas such as the hands, chest and arms. Treatment of the fungus usually results in resolution of the id reaction.
of a potassium hydroxide preparation (known as a KOH test
) may help rule out other possible causes, such as eczema
or psoriasis
. A KOH preparation is performed on skin scrapings from the affected area. The KOH preparation has an excellent positive predictive value, but occasionally false negative results may be obtained, especially if treatment with an antifungal medication has already begun.
If the above diagnoses are inconclusive or if a treatment regimen has already been started, a biopsy
of the affected skin (i.e. a sample of the living skin tissue) can be taken for histological examination.
A Wood's lamp, although useful in diagnosing fungal infections of the scalp (tinea capitis
), is not usually helpful in diagnosing tinea pedis, since the common dermatophytes that cause this disease do not fluoresce under ultraviolet light. However, it can be useful for determining if the disease is due to a nonfungal afflictor.
Athlete's foot is a communicable disease caused by a parasitic fungus in the genus Trichophyton
, either Trichophyton rubrum
or Trichophyton mentagrophytes. It is typically transmitted in moist environments where people walk barefoot
, such as showers, bath house
s, and locker rooms. It can also be transmitted by sharing footwear with an infected person, or less commonly, by sharing towels with an infected person.
To other parts of the body
The various parasitic fungi that cause athlete's foot can also cause skin infections on other areas of the body, most often under toenails (onychomycosis
) or on the groin (tinea cruris).
Hygiene, therefore, plays an important role in managing an athlete's foot infection. Since fungi thrive in moist environments, keeping feet and footwear as dry as possible, and avoiding sharing towels, etc., aids prevention of primary infection.
in conjunction with hygiene measures outlined in the above section on prevention. Keeping feet dry and practicing good hygiene is crucial to preventing reinfection. Severe or prolonged fungal skin infections may require treatment with oral antifungal medication. Zinc oxide-based diaper rash ointment may be used; talcum powder can be used to absorb moisture to kill off the infection.
agents, which can take the form of a spray, powder, cream, or gel. There exists a large number of antifungal drugs including: miconazole nitrate, clotrimazole
, and nystatin
.
A solution of 1% potassium permanganate
dissolved in hot water may be found to be an excellent alternative to antifungal drugs.
The time-line for cure may be long, often 45 days or longer. The recommended course of treatment is to "continue to use the topical treatment for four weeks after the symptoms have subsided" to ensure the fungus has been completely eliminated. However, because the itching associated with the infection subsides quickly, patients may not complete the courses of therapy prescribed.
Anti-itch creams are not recommended, as they will alleviate the symptoms, but will exacerbate the fungus; this is because anti-itch creams typically enhance the moisture content of the skin and encourage fungal growth.
If the fungal invader is not a dermatophyte, but a yeast, other medications such as fluconazole
may be used. Typically, fluconazole is used for candidal vaginal infections (moniliasis), but has been shown to be of benefit for those with cutaneous yeast infections, as well. The most common of these infections occur in the web (intertriginous) spaces of the toes and at the base of the fingernail or toenail. The hallmark of these infections is a cherry red color surrounding the lesion and a yellow thick pus.
. Other prescription oral antifungals include itraconazole
and fluconazole
.
may improve the symptoms but does not cure the underlying fungal infection. Ajoene
, a compound found in garlic, is sometimes used to treat athlete's foot. Urinating on the feet during a shower may also help with the treatment of athlete's foot.
Trichophyton
The fungus genus Trichophyton is 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 um in size....
and is typically transmitted in moist areas where people walk barefoot, such as showers or bathhouses. Although the condition typically affects the feet, it can spread to other areas of the body, including the groin
Groin
In human anatomy, the groin areas are the two creases at the junction of the torso with the legs, on either side of the pubic area. This is also known as the medial compartment of the thigh. A pulled groin muscle usually refers to a painful injury sustained by straining the hip adductor muscles...
. Athlete's foot can be treated by a number of pharmaceutical and other treatments.
Signs and symptoms
Athlete's foot causes scaling, flaking, and itching of the affected skin. Blisters and cracked skin may also occur, leading to exposed raw tissue, pain, swelling, and inflammation. Secondary bacterial infection can accompany the fungal infection, sometimes requiring a course of oral antibiotics.The infection can be spread to other areas of the body, such as the groin
Groin
In human anatomy, the groin areas are the two creases at the junction of the torso with the legs, on either side of the pubic area. This is also known as the medial compartment of the thigh. A pulled groin muscle usually refers to a painful injury sustained by straining the hip adductor muscles...
, and usually is called by a different name once it spreads, such as tinea corporis
Tinea corporis
Tinea corporis is a superficial fungal infection of the arms and legs, especially on glabrous skin, however it may occur on any part of the body.-Symptoms:...
on the body or limbs and tinea cruris (jock itch or dhobi itch) for an infection of the groin. Tinea pedis most often manifests between the toes, with the space between the fourth and fifth digits most commonly afflicted.
Some individuals may experience an allergic response to the fungus called an "id reaction" in which blisters or vesicles can appear in areas such as the hands, chest and arms. Treatment of the fungus usually results in resolution of the id reaction.
Diagnosis
Athlete's foot can usually be diagnosed by visual inspection of the skin, but where the diagnosis is in doubt direct microscopyMicroscopy
Microscopy is the technical field of using microscopes to view samples and objects that cannot be seen with the unaided eye...
of a potassium hydroxide preparation (known as a KOH test
KOH test
The KOH Test for Candida albicans, also known as a potassium hydroxide preparation, is a quick, inexpensive fungal test to differentiate between dermatophytes and Candida albicans symptoms from other skin disorders like psoriasis and eczema....
) may help rule out other possible causes, such as eczema
Eczema
Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...
or psoriasis
Psoriasis
Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
. A KOH preparation is performed on skin scrapings from the affected area. The KOH preparation has an excellent positive predictive value, but occasionally false negative results may be obtained, especially if treatment with an antifungal medication has already begun.
If the above diagnoses are inconclusive or if a treatment regimen has already been started, a biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
of the affected skin (i.e. a sample of the living skin tissue) can be taken for histological examination.
A Wood's lamp, although useful in diagnosing fungal infections of the scalp (tinea capitis
Tinea 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...
), is not usually helpful in diagnosing tinea pedis, since the common dermatophytes that cause this disease do not fluoresce under ultraviolet light. However, it can be useful for determining if the disease is due to a nonfungal afflictor.
Transmission
From person to personAthlete's foot is a communicable disease caused by a parasitic fungus in the genus Trichophyton
Trichophyton
The fungus genus Trichophyton is 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 um in size....
, either Trichophyton rubrum
Trichophyton rubrum
Trichophyton rubrum is a fungus that is the most common cause of athlete's foot, jock itch and ringworm. This fungus was first described by Malmsten in 1845....
or Trichophyton mentagrophytes. It is typically transmitted in moist environments where people walk barefoot
Barefoot
Barefoot is the state of not wearing any footwear. Being barefoot is regarded as a human's natural state, though for functional, fashion and social reasons footwear is worn, at least on some occasions...
, such as showers, bath house
Public bathing
Public baths originated from a communal need for cleanliness. The term public may confuse some people, as some types of public baths are restricted depending on membership, gender, religious affiliation, or other reasons. As societies have changed, public baths have been replaced as private bathing...
s, and locker rooms. It can also be transmitted by sharing footwear with an infected person, or less commonly, by sharing towels with an infected person.
To other parts of the body
The various parasitic fungi that cause athlete's foot can also cause skin infections on other areas of the body, most often under toenails (onychomycosis
Onychomycosis
Onychomycosis means fungal infection of the nail. It is the most common disease of the nails and constitutes about a half of all nail abnormalities....
) or on the groin (tinea cruris).
Prevention
The fungi that cause athlete's foot can live on shower floors, wet towels, and footwear, and can spread from person to person from shared contact with showers, towels, etc.Hygiene, therefore, plays an important role in managing an athlete's foot infection. Since fungi thrive in moist environments, keeping feet and footwear as dry as possible, and avoiding sharing towels, etc., aids prevention of primary infection.
Treatments
Without medication athlete's foot resolves in 30–40% of cases and topical antifungal medication consistently produce much higher percentages of cure.Medication
Conventional treatment typically involves daily or twice daily application of a topical medicationTopical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
in conjunction with hygiene measures outlined in the above section on prevention. Keeping feet dry and practicing good hygiene is crucial to preventing reinfection. Severe or prolonged fungal skin infections may require treatment with oral antifungal medication. Zinc oxide-based diaper rash ointment may be used; talcum powder can be used to absorb moisture to kill off the infection.
Topical
The fungal infection may be treated with topical antifungalAntifungal drug
An antifungal medication is a medication used to treat fungal infections such as athlete's foot, ringworm, candidiasis , serious systemic infections such as cryptococcal meningitis, and others...
agents, which can take the form of a spray, powder, cream, or gel. There exists a large number of antifungal drugs including: miconazole nitrate, clotrimazole
Clotrimazole
Clotrimazole is an antifungal medication commonly used in the treatment of fungal infections such as vaginal yeast infections, oral thrush, and ringworm...
, and nystatin
Nystatin
Nystatin is a polyene antifungal medication to which many molds and yeast infections are sensitive, including Candida. Due to its toxicity profile, there are currently no injectable formulations of this drug on the US market...
.
A solution of 1% potassium permanganate
Potassium permanganate
Potassium permanganate is an inorganic chemical compound with the formula KMnO4. It is a salt consisting of K+ and MnO4− ions. Formerly known as permanganate of potash or Condy's crystals, it is a strong oxidizing agent. It dissolves in water to give intensely purple solutions, the...
dissolved in hot water may be found to be an excellent alternative to antifungal drugs.
The time-line for cure may be long, often 45 days or longer. The recommended course of treatment is to "continue to use the topical treatment for four weeks after the symptoms have subsided" to ensure the fungus has been completely eliminated. However, because the itching associated with the infection subsides quickly, patients may not complete the courses of therapy prescribed.
Anti-itch creams are not recommended, as they will alleviate the symptoms, but will exacerbate the fungus; this is because anti-itch creams typically enhance the moisture content of the skin and encourage fungal growth.
If the fungal invader is not a dermatophyte, but a yeast, other medications such as fluconazole
Fluconazole
Fluconazole is a triazole antifungal drug used in the treatment and prevention of superficial and systemic fungal infections. In a bulk powder form, it appears as a white crystalline powder, and it is very slightly soluble in water and soluble in alcohol. It is commonly marketed under the trade...
may be used. Typically, fluconazole is used for candidal vaginal infections (moniliasis), but has been shown to be of benefit for those with cutaneous yeast infections, as well. The most common of these infections occur in the web (intertriginous) spaces of the toes and at the base of the fingernail or toenail. The hallmark of these infections is a cherry red color surrounding the lesion and a yellow thick pus.
Oral
For severe cases, the current preferred oral agent in the UK is the more effective terbinafineTerbinafine
Terbinafine hydrochloride is a...
. Other prescription oral antifungals include 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 fluconazole
Fluconazole
Fluconazole is a triazole antifungal drug used in the treatment and prevention of superficial and systemic fungal infections. In a bulk powder form, it appears as a white crystalline powder, and it is very slightly soluble in water and soluble in alcohol. It is commonly marketed under the trade...
.
Alternative treatments
Tea tree oilTea tree oil
Tea tree oil, or melaleuca oil, is a pale yellow colour to nearly clear essential oil with a fresh camphoraceous odor. It is taken from the leaves of the Melaleuca alternifolia, which is native to the northeast coast of New South Wales, Australia...
may improve the symptoms but does not cure the underlying fungal infection. Ajoene
Ajoene
Ajoene is a chemical compound available from garlic . The name is derived from "ajo", the Spanish word for garlic. It is found as a mixture of two isomers, E-, and Z- 4,5,9-trithiadodeca-1,6,11-triene 9-oxide....
, a compound found in garlic, is sometimes used to treat athlete's foot. Urinating on the feet during a shower may also help with the treatment of athlete's foot.
External links
- MedlinePlusMedlinePlusMedlinePlus is a free Web site that provides consumer health information for patients, families, and Health care providers. The site brings together information from the United States National Library of Medicine, the National Institutes of Health , other U.S. government agencies, and...
Athlete's Foot Article - WebMDWebMDWebMD is an American corporation which provides health information services. It was founded in 1996 by Jim Clark and Pavan Nigam as Healthscape, later Healtheon, and then acquired WebMD in 1999 to form Healtheon/WebMD...
Athlete's Foot Article