Dermatophyte Nail Fungus

Dermatophyte nail fungus is a term that refers to just one of the kinds of fungal nail infection (onychomycosis) that people commonly get. Specifically, it tells us that the fungus growing in the nail is a dermatophyte—a skin-loving species that derives its nutrients from keratin, a protein found in skin, hair, and nails. This is the most common type of onychomycosis—the kind that is passed from person to person and picked up in swimming pools, public showers, and shared socks and shoes.

Dermatophyte nail infection is caused by a group of fungi, but the most common are Trichophyton spp., usually T. rubrum. In the typical clinical picture, the fungus gains access from the leading edge of the nail, where tiny fungal elements can lodge under the nail and begin to flourish in the warm moist conditions there. This is called distal subungual onychomycosis (distant from the nail bed, under the nail), and this type of dermatophyte nail fungus generally advances back toward the cuticle at a slow but steady rate.

In dermatophyte nail infection the nail may turn white, yellowish, brown, or black. (A green color suggests that the invading organism may be bacteria rather than fungus). The color results from pigments produced by the fungus while it is growing. Eventually, as the dermatophyte nail fungus breaks down all the keratin in the nail, the nail becomes soft and flaky. Pieces break away, and the tissue surrounding the nail may become irritated. In an advanced case, the entire nail is destroyed.

Onychomycosis is very common—dermatophyte nail fungus is found all over the world, and it is typically seen more often in older people. Once it is well established in the nail, it’s difficult to eradicate so any symptoms of dermatophyte nail infection should be seen promptly by a medical professional. Once the diagnosis is confirmed, the patient has a number of choices for treatment, raging from oral prescription drugs and topical treatments to natural alternatives. Don’t discount the alternative treatments too quickly—some of them are backed up by considerable scientific and anecdotal experience.