Evaluation of fluorescence microscopy using acridine orange stain versus hematoxylin and eosin stain in the diagnosis of onychomycosis

Background fluorescent microscope examination of films stained with hematoxylin and eosin (h&e) stain was recommended for its diagnostic utility in the identification of fungal structures. objective to evaluate acridine orange (ao) stain versus h&e stain in the diagnosis of onychomycosis by a fluorescence microscope. patients and methods thirty-five patients with clinically suspected onychomycosis were subjected to an examination of their nail samples by potassium hydroxide 20% direct light microscopic examination, mycological culture by light microscopy, and fluorescence microscope using ao stain and h&e stain. results fungal fluorescence was observed as spores, thin septate, or broad aseptate filaments with a fluorescence outline. ao-stained films yielded the same positivity (91%) as the potassium hydroxide 20% and mycological culture. there was a significant difference on comparing ao-stained films versus h&e-stained films examined by fluorescence microscopy (91, 14.3%; p<0.05, respectively). ao-stained films clearly identified and differentiated the fungi from artifacts. conclusion ao has high credibility in detecting fungal infections compared with h&e stain. fluorescence microscope examination with ao stain is reliable in the diagnosis of onychomycosis.