Cause of Nail Fungus

The cause of nail fungus infection is nearly always one of a small group of fungi and yeasts that are capable of drawing nutrition from keratin, a protein found in nails, or of invading the soft tissue around the nail. The organisms that can do this fall into three groups: dermatophytes, saprophytes, and yeasts. The dermatophytes are the most common offenders.

An advancing fungus under nail plate areas is usually a dermatophyte. These fungi are adapted for life on the hair, skin, nails, and horns of animals. They metabolize keratin and spread throughout a finger nail or toe nail and often to other nails as well. These fungi are the most common cause of nail fungus because keratin containing tissue is their natural environment - they survive well in damp areas in the environment, but proliferate on the nonliving tissues of live animals. These fungi are often picked up from shared shoes and from walking barefoot in public places where moisture favors the fungi - swimming pool decks, public showers and dressing rooms etc. Some type of footwear is advised in these locations.

Saprophytes are environmental fungi that normally grow on dead and decaying organic matter; therefore, they are a relatively rare cause of nail fungus infection. They are all common in the environment and can be contracted by farmers, gardeners, landscapers, and other people who work with plants or soil. It's a good idea to wear gloves if you're working outside: dirt and fungus under nail edges can set up a fungal infection if there are any breaks in the skin.

While it's usual to get a fungus under nail edges and plates, yeast infections tend to set in under different circumstances. These organisms take advantage of very damp conditions - the fingernails of people who have their hands in water a great deal are particularly vulnerable. When there is constant moisture, the nail becomes soft. Yeast cells invade and start to proliferate, causing lifting and buckling of the nail itself, and swelling and inflammation in the surrounding soft tissue. In severe infections, there is extreme inflammation and production of pus. Unlike the average fungal cause of nail fungus, a yeast nail infection tends to be more acute, more uncomfortable, and more urgent.