SIGNIFICANCE OF NON-DERMATOPHYTE MOLDS AND YEASTS IN ONYCHOMYCOSIS

In a multicentre, randomised, double-blind, 48-week clinical trial, 11 8 patients with toe-nail onychomycosis were given terbinafine (250 mg daily) or placebo for 12 weeks, followed by 12 weeks of observation. N on-responders were offered 12 further weeks of terbinafine (250 mg dai ly) from week 28. Each patient had 8-12 consecutive nail specimens col lected from the same nail, allowing for an assessment of the fungal na il flora from 1,321 nail specimens. By week 48, the overall mycologica l cure rate for terbinafine patients was 94%. 64% of patients had an u nderlying dermatophyte infection with at least 1 non-dermatophyte moul d or yeast isolated from at least 1 specimen. These contaminants often overgrow or mask the presence of a dermatophyte. In only 2.5% of all patients was the same non-dermatophyte isolated from 2 or more consecu tive specimens, probably representing secondary colonisation which exp loits nutrients released by the underlying dermatophyte. The presence of incidental non-dermatophyte contaminants or secondary colonisers di d not affect treatment outcome, and in this study treatment of the pri mary dermatophyte pathogen with terbinafine cleared the nails from inf ection in all cases. 80% of patients remained mycologically negative a fter 2 years.