Comment: The quality of evidence is downgraded by study limitations (in most studies unclear allocation concealment and blinding of outcome assessment, and in half of the trials incomplete outcome data), by imprecise results (few patients), and upgraded by large magnitude of effect.
A Cochrane review «Topical antifungal treatments for tinea cruris and tinea corporis»1 «El-Gohary M, van Zuuren EJ, Fedorowicz Z et al. To...»1 included 129 studies with a total of 18 086 subjects. 63 studies contained no usable or retrievable data. A wide range of different comparisons were evaluated. Duration of the treatment was in most studies 2 to 4 weeks (variation from1 to 8 weeks) and the length of follow-up varied from 1 week to 6 months. Significantly higher clinical cure rates were seen in participants treated with terbinafine compared to placebo (RR 4.51, 95% CI 3.10 to 6.56; number needed to treat (NNT) 3, 95% CI 2 to 4; 5 trials, n=273). Data for mycological cure for terbinafine could not be pooled due to substantial heterogeneity. Mycological cure rates favoured naftifine 1% compared to placebo (RR 2.38, 95% CI 1.80 to 3.14; NNT 3, 95% CI 2 to 4; 3 trials, n=187). Mycological cure rates favoured clotrimazole 1% compared to placebo (RR 2.87, 95% CI 2.28 to 3.62; NNT 2, 95% CI 2 to 3; 2 trials, n=344).
There was no difference in mycological cure between azoles and benzylamines (RR 1.01, 95% CI 0.94 to 1.07; 3 trials, n=219). Substantial heterogeneity precluded the pooling of data (over 600 participants) for mycological and clinical cure when comparing azoles and allylamines (e.g. terbinafine). Azoles were slightly less effective in achieving clinical cure compared to azole and steroid combination creams immediately at the end of treatment (RR 0.67, 95% CI 0.53 to 0.84; NNT 6, 95% CI 5 to 13; 4 trials, n=353), but there was no difference in mycological cure rate (RR 0.99, 95% CI 0.93 to 1.05; 6 trials, n=625).