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 UK guidelines and reviews) that self care alone may be considered as an option [Roberts et al, 2003; DTB, 2008].

Topical antifungals

• UK guidelines state that topical treatment for dermatophyte infection can only be recommended for the treatment of superficial white onychomycosis and very early cases of distal and lateral subungual onychomycosis where the infection is confined to the distal edge of the nail [Roberts et al, 2003]. This is because:
• Topical amorolfine has evidence of limited effectiveness for dermatophyte infections.
• There is no good evidence from randomized controlled trials on other topical treatments for dermatophyte nail infections, including Topical tioconazole, Topical salicylic acid, and Topical undecenoates.

Confirming the diagnosis by mycological microscopy or culture before starting treatment is recommended [Roberts et al, 2003] because:

• It is not possible to make a confident diagnosis of dermatophyte nail infection solely on the basis of the clinical history and examination.
• Dermatophyte nail infection progresses slowly and there is nothing to lose if treatment is delayed by a few weeks. However, treatments can have adverse effects.

Safety of oral antifungal treatments

• There is evidence from a systematic review that oral antifungal treatment for superficial dermatophytosis and onychomycosis is associated with a low incidence of serious adverse events in immunocompetent people. The systematic review included data from randomized controlled trials (RCTs) and observational studies.

Oral terbinafine

• There is moderate evidence from RCTs that oral terbinafine is effective.
• There is weak evidence from RCTs that oral terbinafine may be more effective than oral itraconazole.
• There are fewer drug interactions with oral terbinafine than with azole antifungals, and adverse effects are usually mild and transient although there are concerns about liver toxicity.

Oral itraconazole

• There is weak evidence from RCTs that oral itraconazole is effective.
• There is weak evidence from RCTs that oral itraconazole may be less effective than oral terbinafine.
• Pulsed therapy is recommended because there is no good evidence that it is less effective than continuous therapy, and it may reduce the risk of adverse effects.
• However, this dosing regimen is not licensed [ABPI Medicines Compendium, 2008].

Treatments that are not recommended

• Combined topical treatment and oral drug treatment are not recommended because there is only weak evidence for oral terbinafine combined with topical treatments, and weaker evidence for oral itraconazole combined with topical treatments.
• 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.
• Oral griseofulvin is not recommended because there is evidence from RCTs that it is less effective than oral terbinafine, and weak evidence from RCTs that it is less effective than oral itraconazole. Also, adverse effects are more of a concern with griseofulvin [Roberts et al, 2003].