Results of German multicenter study of antimicrobial susceptibilities of Trichophyton rubrum and Trichophyton mentagrophytes strains causing tinea unguium. German Collaborative Dermatophyte Drug Susceptibility Study Group.

Thirty-two strains of Trichophyton rubrum and 16 strains of Trichophyton mentagrophytes isolated from patients with tinea unguium in various parts of Germany were subjected to a microdilution test with six systemic or topical antimycotic agents. Apart from griseofulvin, there were no species-specific differences between the two species. Terbinafine was the most active antimycotic agent, with a MIC not exceeding 0.05 micrograms/ml.