Evaluation of combined deactivators-supplemented agar medium (CDSAM) for recovery of dermatophytes from patients with tinea pedis.

Using a newly-developed medium, i.e., combined deactivators-supplemented agar medium (CDSAM), the viability of dermatophytes in skin scales was evaluated. Culture studies were conducted with skin scales collected from 44 patients with tinea pedis who had been treated for two weeks with topical antifungal drugs. Sixty-four percent of the specimens were mycologically positive on CDSAM, while only 23% of these same specimens were positive when cultured on conventional Sabouraud's dextrose agar medium (SDA). Alternatively, 36% of all cases were negative on both media. The experimental data from this clinical study indicate that CDSAM was more useful than SDA in accurately evaluating the efficacy of antifungal drugs since the former minimized the residual effects of drug residues remaining in the skin samples.