Fluorescence staining vs. routine KOH smear for rapid diagnosis of oral candidiasis-A diagnostic test

A diagnostic test was designed to evaluate the accuracy and applicability of fluorescence staining with fluorescein-labelled chitinase versus routine 10% potassium hydroxide (KOH) smear for rapid diagnosis of oral candidiasis.

In total, 124 subjects with suspected oral candidiasis symptoms/signs were sequentially enrolled in this study. The diagnostic efficacy indexes (sensitivity, specificity, Youden index, predictive value, likelihood ratio, diagnostic odds ratio, diagnostic accuracy and area under the curve [AUC]) were compared between 10% KOH smear and fluorescence staining.

The sensitivity (85.48% vs. 64.52%) and specificity (91.94% vs. 72.58%) of fluorescence staining were higher than those of KOH smear. The AUC of fluorescence staining (0.887) was remarkably higher than that of 10% KOH smear (0.685), demonstrating that the diagnostic efficacy of fluorescence staining is significantly higher than that of KOH smear (p = .0005). Furthermore, fluorescence staining showed higher sensitivity than that of KOH smear (84.75% vs. 62.71%) in diagnosis of erythematous type oral candidiasis, which is the most common type and the type most challenging to differentially diagnose.

The advantages of fluorescence staining with fluorescein-labelled chitinase in rapid diagnosis of oral candidiasis and its ease of operation suggest its potential use in clinical practice.