Topical antifungals are difficult to use effectively because it is difficult to get the drug to the site of infection in the nail bed. Antifungal nail polish (amorolfine) can be effective, but has to be applied regularly over at least six months so good adherence is essential. It is also important to reduce nail thickness by filing the top of the nail as much as possible to enhance penetration of the drug. Podiatrists can also reduce nail thickness using specialised equipment.

Two other approaches can improve delivery of the drug to the site of action:

• 40% urea can be used to remove the infected parts of the nail followed by topical treatment with an azole or terbinafine. Canespro is a kit for this purpose
• Fenestration – the drilling of small holes through the nail – can be undertaken by a podiatrist, followed by application of terbinafine spray.

Laser treatments are no better than other treatments and are very expensive. There is also some evidence for the effectiveness of a pine resin product, although it has to be applied daily for nine months.

Systemic treatment has about a 70 per cent success rate. Terbinafine treatment comprises 250mg daily for 12-16 weeks for toenail infection. Itraconazole treatment involves either 200mg daily for 12 weeks or 400mg daily for one week per month and three treatments are recommended for toenail infection.