Toe nail fungus is a phrase often used to refer to a common type of fungal infection – an infection where a fungus has somehow gotten into a toenail and begun to grow there, causing discoloration, disintegration of the nail and, frequently, considerable discomfort. Although there are many species of fungi in the world, only a relatively small number of them are capable of living and growing on human nails. Most of them belong to a group collectively known as dermatophytes: these fungi typically live on hair, skin, and nails and spread from person to person. A few others belong to the saprophytes, fungi that live on decaying organic materials in nature and sometimes infect nails more or less accidentally.
Invading fungus in nail and skin is fairly common – more than ten percent of the North American population suffers from such an infection, with the risk increasing with age. While fungal invasion of a fingernail does occur, toe nail fungus is much more common, probably because feet have more contact with damp earth and floors, are washed less frequently, and spend more time in enclosed, humid coverings such as shoes and boots. Fungal nail infections tend to start in a toe nail and then spread to other toe nails, skin, and finger nails secondarily.
Risk factors for acquiring a toe nail fungus include injury to the nail or the skin around the nail. Cuts and scrapes, hangnails, ingrown toenails, dry cracked skin and damp conditions all provide a route of entry into the skin and nails, as will toenails that are damaged or deformed due to recent or prior injury. Nails that have lifted away from the nail bed are particularly susceptible. Public swimming and wading pools, public showers, and shared footwear are all likely places to come in contact with a dermatophyte. Saprophytes are more likely to come from soil, decaying leaves or other organic material in the environment. In salons, fungus in nail clippings and filings or on manicure or pedicure equipment is a documented source of infection in people who use these services.
Once established, a toe nail fungus is generally quite difficult to get rid of. The invader grows within the nail itself, deriving nutrients from keratin, a protein found in nails, hair and skin cells. Nails are meant to be a tough shield to protect the tips of our fingers and toes, and they are quite good at blocking medications and treatments applied to nails. In order to kill the fungus, you need to find something that can penetrate the nail or get underneath it like the fungus did. Most prescription medications are taken internally and act on the infection systemically, while natural and home remedies are applied topically. The key to any treatment for fungus in nail infections is patience: nails grow slowly and it usually takes months before the nail looks normal again.
Any suspected toe nail fungus infection should be seen and diagnosed by a doctor because other types of nail infection and nail abnormality can mimic a fungal infection. If the problem is fungal, spores of the fungus in nail clippings will grow in the laboratory and the fungal species can be identified. Once you know for sure that the problem is fungal, treatment can be started.