Dermatophytosis

Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD's medical weight loss NYC, sleep center NYC
Philadelphia medical weight loss and Philadelphia sleep clinics

Dermatophytosis
Synonyms	Tinea, ringworm
Pronounce	N/A
Specialty	N/A
Symptoms	Itching, redness, scaling, cracking of the skin
Complications	Secondary bacterial infection
Onset	Varies by type
Duration	Weeks to months
Types	N/A
Causes	Dermatophyte fungi
Risks	Humidity, sweating, immunocompromised state
Diagnosis	Clinical examination, KOH test, fungal culture
Differential diagnosis	Eczema, psoriasis, candidiasis
Prevention	Keeping skin dry, avoiding sharing personal items
Treatment	Antifungal medications (topical or oral)
Medication	Clotrimazole, terbinafine, griseofulvin
Prognosis	N/A
Frequency	Common
Deaths	N/A

A common fungal infection of the stratum corneum of the skin, hair, or nails by a dermatophyte.

Other names

• Ringworm
• Tinea
• Athlete's foot (location specific)

Clinical features

It is characterized by itching, inflammation, redness of the skin, small papular vesicles, central clearing, fissures, scaling, and/or hair loss in the affected area.

Cause

Ringworm is a common skin infection that is caused by fungus. Areas of the body that can be affected by ringworm include:

• Feet (tinea pedis, commonly called ‚Äúathlete‚Äôs foot‚Äù)
• Groin, inner thighs, or buttocks (tinea cruris, commonly called ‚Äújock itch‚Äù)
• Scalp (tinea capitis)
• Beard (tinea barbae)
• Hands (tinea manuum)
• Toenails or fingernails (tinea unguium, also called ‚Äúonychomycosis‚Äù) Click here for more information about fungal nail infections.
• Other parts of the body such as arms or legs (tinea corporis)

Fungal species

• Approximately 40 different species of fungi can cause ringworm;
• The scientific names for the types of fungi that cause ringworm are Trichophyton, Microsporum, and Epidermophyton.

Diagnosis

Physical examination

• A thorough history and physical examination is often sufficient to diagnose tinea.
• The classic lesion is an erythematous, raised, scaly ring with central clearing.
• Multiple lesions may be present.

Microscopy

• Potassium hydroxide (KOH) stain a commonly-used method for diagnosing tinea because it is inexpensive, easy to perform, and has high sensitivity.
• Scrapings from the lesion(s) are placed in a drop of KOH and examined under a microscope for the presence of fungal hyphae.

Ultraviolet light (Wood’s lamp)

• Normally, ultraviolet light is not useful in the diagnosis of tinea with the exception of two species – Microsporum canis and audouinii.
• Although both species fluoresce blue-green under a Wood‚Äôs lamp, both species are uncommon causes of tinea infections.
• A Wood‚Äôs lamp may be useful to differentiate between erythrasma caused by Corynebacterium minutissimum (which fouresces coal-red) from tinea cruris, which is non-fluorescent.

Culture

• Fungal culture can be performed as a confirmatory test if results from a KOH stain are inconclusive.
• Hair and/or scrapings extracted from affected areas are placed on Sabouraud‚Äôs medium.
• Fungal culture is more specific than KOH stain, but it can take up to three weeks to become positive.

Treatment

• Some forms of ringworm can be treated with non-prescription (‚Äúover-the-counter‚Äù) antifungal creams, lotions, or powders.
• Other forms of ringworm need treatment with prescription antifungal medications depending on the type of fungus.

Tinea pedis: Athlete’s foot can usually be treated with over-the-counter topical antifungal products;

• terbinafine appears to be most effective, but other agents can also be used.
• Chronic or extensive tinea pedis may require treatment with oral antifungal agents such as terbinafine, itraconazole, or fluconazole.
• In addition, chronic tinea pedis may require adjunctive therapy such as foot powder or talcum powder to prevent skin maceration.

Tinea capitis: Treatment with systemic antifungal medication is required, as topical antifungal products are ineffective for treatment of tinea capitis.

• Many experts consider griseofulvin to be the drug of choice.
• Terbinafine is also FDA-approved for the treatment of tinea capitis in patients four years of age and older.
• Itraconazole and fluconazole have been shown to be safe and effective, but are not FDA-approved for this indication.
• Selenium sulfide shampoos can be used as adjunctive therapy.

Tinea corporis/Tinea cruris: Tinea corporis and tinea cruris can usually be treated with over-the-counter antifungal products.

• Patients who have tinea cruris should be advised to keep the groin area clean and dry and to wear cotton underwear.
• Persons who have extensive or recurrent infections may require systemic antifungal therapy.

Steroids should not be used

• People who have ringworm don‚Äôt always know what‚Äôs causing their rash, and people sometimes apply over-the-counter creams or ointments containing corticosteroids (or ‚Äústeroids‚Äù for short) to their rash.
• Steroid creams don‚Äôt kill the fungus that causes ringworm.
• Steroid creams also can make ringworm worse because they weaken the skin‚Äôs defenses.
• In rare cases, steroid creams allow the fungus that causes ringworm to invade deeper into the skin and cause a more serious condition.
• Steroid creams can make ringworm infections spread to cover more of the body.

An Emerging International Problem in India

• Dermatologists in India have reported severe steroid-modified tinea associated with use of over-the-counter mid- to high-potency topical corticosteroids, which are commonly sold as fixed-dose combinations with an antifungal medication and one or two antibacterial medications.
• In India, a dermatophyte species often identified as Trichophyton mentagrophytes has been reported as the cause of these breakthrough infections.

Gallery

• 
  Dermatophytosis 1
• 
  Dermatophytosis 2
• 
  Dermatophytosis 3
• 
  Dermatophytosis 4
• 
  Dermatophytosis 5
• 
  Dermatophytosis 6
• 
  Dermatophytosis 7
• 
  Athlete's foot

This article is a medical stub. You can help WikiMD by expanding it!
Most recent articles Ongoing trials	Wikipedia