These recommendations reflect expert opinion in reviews and the British Association of Dermatology guidelines, which are based on the best available evidence [Roberts et al, 2003; DTB, 2008; HPA, 2009].

Referral of children requiring oral antifungal treatment

• This is recommended because fungal nail infection is rare in children and the preferred treatments are off-licence.

Self care alone

• Many people are not particularly troubled by their abnormal nails, but available treatments can have adverse effects. Experts therefore recommend (in guidelines published by the British Association of Dermatologists, and reviews) that self care alone be considered as an option [Roberts et al, 2003; DTB, 2008].

Confirming the diagnosis by mycological culture before starting treatment

• Experts and guidelines published by the British Association of Dermatologists recommend that, before treatment is started, the diagnosis of Candida onychomycosis be confirmed by microscopy and culture because [Roberts et al, 2003]:
• It is not possible to make a confident diagnosis of Candida nail infection solely on the basis of the clinical history and examination.
• Distal nail infection with Candida yeasts is uncommon and virtually all people have Raynaud's phenomenon or some other form of vascular insufficiency.
• Candida yeasts are frequently isolated from normal nails [Johnson, Personal Communication, 2009].
• Candida nail infection progresses slowly and there is nothing to lose if treatment is delayed by a few weeks. However, oral treatments can have adverse effects.

Topical antifungals

• Although there is only weak evidence that treatment with topical antifungals alone may be effective in the treatment of Candida nail infection, this is recommended by UK guidelines published by the British Association of Dermatologists, which take account of clinical experience and expert opinion [Roberts et al, 2003].
• CKS does not recommend topical tioconazole because it needs to be administered twice a day and is therefore less practical than topical amorolfine which is administered once or twice a week [ABPI Medicines Compendium, 2007a; ABPI Medicines Compendium, 2007c].

Safety of oral antifungal treatments

• There is evidence from a systematic review of the safety of oral treatments for superficial fungal infections that oral antifungal treatment for superficial dermatophytosis and onychomycosis was associated with a low incidence of serious adverse events in immunocompetent people. The systematic review included data from RCTs and observational studies.

Oral itraconazole

• There is evidence that oral itraconazole effectively treats Candida nail infection.
• No clinical trials have directly compared oral with topical itraconazole; the evidence that treatment with topical treatment alone may be effective in the treatment of Candida nail infection is limited.
• No clinical trials have directly compared oral itraconazole with oral terbinafine, but there is weak evidence that oral terbinafine may be effective in Candida nail infection.

Treatments that are not recommended

• There is no good evidence that combining oral itraconazole with topical antifungals offers any advantage in comparison with systemic treatment alone.
• Oral griseofulvin is seldom used because adverse effects are more of a concern [Roberts et al, 2003].
• Ageratina pichinchensis plant extract is not recommended because, although there is weak evidence of effectiveness, it does not appear to be more effective than topical amorolfine, and there is no good evidence on its safety.
• Topical tea tree oil (from the Melaleuca alternifolia plant) is not recommended because, although there is weak evidence of effectiveness, it does not appear to be more effective than topical amorolfine, and there is no good evidence on its safety.