Topical management of tinea pedis

Clinical question

How effective are topical treatments for tinea pedis?

Bottom line

Tinea pedis is successfully treated with topical antifungals in 70% to 75% of patients compared with 20% to 30% using placebo. Tea tree oil is likely ineffective. Topical terbinafine might result in an absolute improvement of 2% to 8% more patients cured over other topicals. Most patients were treated for 1 week with terbinafine and 4 to 6 weeks with azoles (like clotrimazole).

Evidence

Results are statistically significant unless indicated.

• Studies comparing with placebo found the following.

  • - Systematic review (67 RCTs) of mycologically diagnosed tinea pedis (and oncychomycosis, not included here), reporting laboratory-confirmed treatment failure at 6 weeks.¹

    • — Allylamines (eg, terbinafine, naftifine), 9 RCTs (N = 876), 1 to 4 (most 4) weeks’ treatment: 25% versus 80% placebo; number needed to treat (NNT) of 2.

    • — Azoles (eg, clotrimazole, miconazole), 6 RCTs (N = 448), 4 to 6 weeks’ treatment: 28% versus 70% placebo; NNT = 3.

    • — Tea tree oil, 1 RCT (N = 71), 4 weeks’ treatment: no difference from placebo.

  • - Systematic review of topical terbinafine versus placebo, 9 RCTs (N = 986), 1 to 4 (1 most common) weeks’ treatment²: clinical cure, 72% terbinafine versus 28% placebo; NNT = 3.

    • — Other systematic reviews found similar results.^3-5

• Direct comparisons found the following.

  • - Allylamines versus azoles.

    • — Systematic review, 8 RCTs (N = 1034), 1 to 6 (most 1 to 2) weeks’ treatment³: mycological cure, 78% allylamines versus 76% azoles; NNT = 40.

  • - Topical terbinafine versus other antifungals.

    • — Systematic review, 10 RCTs (N = 1341), 1 to 4 (most 1) weeks’ treatment²: clinical cure, 83% terbinafine versus 75% other antifungals (statistical significance reported inconsistently; if real, NNT = 13).

• Adverse events: burning, stinging, and itching sensations were most common (but not quantified).¹

• Limitations: some RCTs¹ and 1 systematic review² were industry funded; clinical cure is less commonly reported than mycological cure.

Context

• Topical antifungals are suggested as first-line agents, reserving oral agents for severe disease (eg, moccasin-type infection), failed topical treatment, and immunocompromised patients.⁶

• Approximate cost (for 30 g)^7-9:

  • - 1% clotrimazole cream, twice daily, $13,

  • - 2% miconazole cream, twice daily, $15, and

  • - 1% terbinafine cream, twice daily, $30.

Implementation

It is uncertain whether foot hygiene or changing footwear is beneficial; however, placebo arms from RCTs suggest it might help.⁴ The Centers for Disease Control and Prevention advise that patients with tinea pedis keep feet dry, clean, and cool; wear sandals, if possible (especially in locker rooms); air out shoes; and wear cotton socks.¹⁰ Patients can discuss over-the-counter options with their pharmacists, such as clotrimazole or miconazole, although these tend to require a longer treatment duration. Nystatin should not be used owing to dermatophyte resistance.⁶ Terbinafine cream, twice a day for 7 days, is a reasonable prescription option with a short treatment duration and well supported efficacy.