Fungal Infections (Tinea)
Fungal infections of the skin and nails are common and include athlete`s foot (tinea pedis), jock itch (tinea cruris), ringworm (tinea corporis), fungal infection of the nail (onychomycosis), and yeast infections which most commonly affect the folds of the skin (neck, underarms, groin, buttocks).
Tinea pedis is a very common cause of peeling, redness, itching, burning, and sometimes blisters and sores of the feet. It is more common in individuals who have excessive sweating of the feet, who wear closed-toe shoes, and who frequent community showers and pools.
Athlete`s foot is caused by a certain category of fungus called dermatophyte, that lives on dead tissue of the hair, toenails, and outer layers of the skin. The most common species of dermatophyte to cause tinea pedis is known as trichophyton rubrum.
The most common sites of infection on the foot include the skin between the toes (interdigital) and the sole and sides of the foot (moccasin distribution). Uncommonly, tinea pedis can present with painful, fluid-filled blisters.
Athlete`s foot can be mistaken for other common rashes occurring on the feet including allergic contact dermatitis, atopic dermatitis and psoriasis.
Preventive measures include the use of sandals in community showers and restrooms, keeping the feet dry with foot powders and wearing shoes that allow the feet to have access to air.
Tinea pedis usually responds to topical antifungal creams.
Tinea cruris is a dermatophyte infection of the inner thighs and less commonly, the genitals, or buttocks. Symptoms include itching, burning of the groin area, and the presence of a red, circular, scaly patches of skin of the affected areas. Jock itch can also be prevented by applying absorbent powders to the groin area. Tinea cruris can usually be cured with the use of topical antifungal creams or sprays.
Ringworm is a misnomer for a dermatophyte (fungal) infection of the skin. The fungus is mildly contagious, spread by direct contact with infected individuals. Occasionally certain animals, especially cats, can harbor and infect humans. Ringworm gets its name from the round and scaly edged appearance of the rash. The rash can occasionally be itchy. Topical antifungal medications are the mainstay of treatment, though systemic antifungals may be appropriate in certain widespread or severe cases of tinea corporis.
Dermatophyte infection of the nails is common. This infection causes thickened, yellow-appearing nails that often lift off the nail bed. Frequently, the infected nail develops crumbly material under the surface of the nail which breaks off easily. Toenail infection is frequently accompanied by tinea pedis. With exception of the most superficial variety of nail fungal infection, onychomycosis only responds to antifungals taken orally.
Yeast infections of the skin are most commonly caused by fungi called candida. A bright red, itchy and occasionally painful rash occurs in warm, moist areas of skin, for example, skin folds of the groin, underarms, neck and buttocks. Risk factors for yeast infections of the skin include diabetes mellitus and obesity. Antibiotic therapy also predisposes people to yeast infections. Besides skin, candida can also infect the nail and nailfold, the tongue and other mucous membranes, as well as cause vaginal yeast infections. Yeast infections generally are not regarded as contagious, and are treated with topical as well as systemic antifungals.