Onychomycosis Dr Rob Hicks Onychomycosis is a fungal infection of the finger or toenail.

In this article

What is onychomycosis? Symptoms

Causes and risk factors Treatment and recovery

There are number of different types of fungal infection that can cause this problem. Our nails help us to manipulate objects, aid our sense of touch and protect the tissues at the end of our fingers and toes. Onychomycosis alters the look of nails, making them very unsightly, and requires treatment.

Onychomycosis usually affects the end of the nail first, before developing further up the digit. However there are several types of onychomycosis and the pattern varies. Toenails are far more often affected than fingernails.

The affected area turns yellow-brown and the nail may thicken, crumble and separate from the nail bed. This thickening, discolouration and disfigurement are clearly visible.

The effects of onychomycosis aren't simply cosmetic. A thickened nail may limit usual activities. It may press on the inside of footwear, for example, causing discomfort and pain. This in turn can cause problems when walking, and reduce mobility.

Anyone can develop onychomycosis, which usually sets in as a result of damage or cracking (often microscopic) of the nail which weakens it and allows fungal spores in the environment to establish an infection. It's more likely to affect people as they get older. About five to ten per cent of adults have the condition, children are rarely affected. However, it can affect as many as 90 per cent of the elderly.

People with diabetes are at greater risk, as are those whose immune system is suppressed.

It's possible to reduce your risk of onychomycosis by practising good nail care. This reduces the risk of other nail and foot-related problems, too.

Onychomycosis is often difficult to treat – it can take many months of antifungal medication, and a lot of persistence, to completely clear the problem. When the infection is limited just to the end of the nail, topical antifungal agents can be painted on but may not penetrate the nail plate far enough to cure the condition.

Antifungal tablets may also be given (sometimes in combination with a topical agent) and the newer drugs are more successful as they penetrate the nail plate more effectively.

Even so it can be a year or more before the nail looks normal again and preventative antifungal treatment may be needed long term to prevent re-infection. In severe cases where pain and immobility is a particular problem, surgical removal of the whole nail may be the best way to cure the problem.

A qualified podiatrist can provide appropriate nail care if necessary.

This article was last medically reviewed by Dr Trisha Macnair in May 2009.