Don't get confused by the “evidence”

Papers p 79

Dermatophyte infections occur often either between the outer toes or in the toenails. It is now possible to eradicate most of these, and more widespread fungal infections, with the new generation of antifungal agents. Competing claims are made for systemic terbinafine and itraconazole, and up to now it has been hard to sort out the science from the marketing. The recent paper by Evans et al1 and the systematic review in this issue by Hart et al (p 79)2 attempt to point ways through the evidence. Other problems remain in treating children and non-responders.

The conclusions reached in the systematic review by Hart et al are undermined by the limited questions asked. It is legitimate to review the evidence for topical treatments for superficial fungal infections of the skin, but common sense must be applied to the results. Use of topical drugs in the community is not necessarily the same as in a trial situation. Poor compliance is common because symptoms are rapidly relieved, whether or not there has been mycological cure. Very few applications of topical (fungicidal) terbinafine are needed to produce a cure, whereas fungistatic drugs must be applied until the infected stratum corneum is shed. One week of topical terbinafine therefore gives better cure rates than four weeks of clotrimazole.3 The implications for …