BACKGROUND: Treatment of tinea pedis and onychomycosis is complicated by high rates of reinfection and the emergence of terbinafine-resistant strains of Trichophyton spp. Effective disinfection of contaminated socks is an important measure. Appropriate washing reduces the risk of reinfection and is paramount in treating tinea pedis and onychomycosis.

OBJECTIVES: The aim of this study is to describe the effect of commonplace disinfection methods using socks pieces inoculated with terbinafine-resistant or terbinafine-susceptible isolates of Trichophyton spp.

METHODS: Sock pieces were inoculated with seven terbinafine-resistant isolates of Trichophyton spp. with known mutations in the SQLE-gene (T. rubrum (n=3), T. interdigitale (n=1), and T. indotineae (n=3)) and six terbinafine-susceptible isolates of Trichophyton spp. (T. rubrum (n=3) and T. interdigitale (n=3)). Methods of disinfection included soaking in a quaternary ammonium (QAC) detergent (0.5, 2, and 24 hours), freezing at -20°C (0.5, 12, and 24 hours), domestic washing (40°C with detergent), and steam washing (40°C with detergent). Sock pieces were cultured for 4 weeks following disinfection. The primary end point was no growth at the end of week 4.

RESULTS: Soaking in QAC-detergent for 24 hours procured at disinfectant rate of 100% (13/13), whilst soaking in 0.5 and 2 hours had a disinfectant rate of 46% (6/13) and 85% (11/13), respectively. Domestic washing (40°C with detergent) produced a disinfectant rate of 7.7% (1/13). Freezing at -20°C (0.5, 12, and 24 hours) and steam washing (40°C with detergent) had no disinfectant properties.

CONCLUSIONS: Soaking socks contaminated with dermatophytes in a QAC-detergent for 24 hours disinfects socks.