Onychomycosis is common in adults and constitutes 20% of all nail disease.
Widely used methods to confirm a clinical diagnosis of onychomycosis often
yield negative results (ie, potassium hydroxide [KOH] preparation) or are s
low (ie, dermatophyte cultures). We report a case of onychomycosis in which
we used in vivo confocal microscopy to diagnose the disease; we also corre
lated our findings with results from routine KOH preparations. On the basis
of our findings, we hypothesize that in vivo confocal microscopy may be fa
ster and more accurate than the conventional microscope used in KOH prepara
tions in the diagnosis of onychomycosis.