A new combined diagnostic approach to clinically and microscopically suspected onychomycosis unproven by culture.

In clinical practice the suspicion of onychomycosis in a diseased nail plate is not infrequently substantiated by microscopic evaluation of scrapings using a KOH preparation but not by culture. As this may be partly due to inadequate sampling an alternative sampling method may in principle be beneficial. Based on good anecdotal reports of high-speed fraising this method was used in 24 patients. If culture again proved negative high-speed fraising was repeated in conjunction with nail biopsy. In the majority of cases high-speed fraising provided specimens allowing culture of the causative organism. If not, nail biopsy was of additional help. As repeated high-speed fraising is a non-invasive non-laborious method it can be advocated as an additional routine step in the diagnosis of clinically and microscopically suspected onychomycosis initially unproven by culture. Microscopic examination of a biopsy should be considered if material obtained by repeated high-speed fraising does not reveal fungi upon culture.