Do you have one or more unsightly nails? If so, you may have an infection with tinea (a fungus). Tinea is the commonest cause of deformed nails and effective treatment is available.

Tinea in the nails (onychomycosis) causes discolouration, thickening and crumbling under the end of the nail. The infection usually starts as scaly patches on the skin (ringworm), between the toes (athlete's foot), groin (jock itch) or scalp (patches of hair loss and scaling). Later on, the infection may spread to the nails.

There are many other causes of nail disease. To make sure tinea is the culprit, your doctor may arrange for a nail sample to be examined under a microscope and cultured in the laboratory. It can take up to 5 weeks to get a final report.

How is tinea of the nails treated?

As the nails are very thick, creams do not work. The most effective treatment is a once-daily tablet called terbinafine, which goes to the bloodstream and attacks the infection from within the body. Most people require 6 weeks for finger nails and 12 weeks for toenails. Terbinafine is usually well tolerated, however it can cause nausea, abdominal pain and allergic skin reactions.

Several other alternative drugs are available, but are used less frequently.

A nail lacquer called amorolfine may be effective in mild cases, and is applied directly to the nail surface once a week. A 6 to 12 month course is usually needed.

How to prevent nail infection

Treat tinea on the skin promptly before it spreads to the nails. Tinea is most often caught when barefoot in communal areas, eg swimming pools or gyms, or from shared shoes, eg at bowling alleys. To avoid tinea:

• Wear thongs or sandals in shared showers.
• Dry your feet and body thoroughly.
• Do not share towels, shoes and clothing.
• Wear loose-fitting clothing, cotton underwear and socks.