Application of confocal laser scanning microscopy in the diagnosis of superficial cutaneous fungal infections

Abstract

Objective To estimate the performance of confocal laser scanning microscopy (CLSM) in the diagnosis of superficial cutaneous fungal infections. Methods This study recruited 59 patients with clinically suspected superficial cutaneous fungal infections.Three typical lesions were selected in each patient for CLSM and microscopic examination.Results CLSM revealed hyphae in stratum corneum in 56％ (14/25) of tinea manus or pedis and 79.17％ (19/24) of tinea cruris lesions,7 out of 8 tinea manus or pedis and 94.12％( 16/17 ) of tinea cruris early lesions (＜ 3 weeks ),and 41％ (7/17) of tinea manus or pedis and 3 out of 7 tinea croris old lesions (＞ 3 weeks).All the CLSM-positive specimens were positive for microscopic examination,and among the CLSM-negative specimens,fungal elements were observed by microscopic examination in 8 out of 11 tinea manus or pedis specimens,4 out of 5 tinea cruris specimens,1 tinea manus or pedis and 1 tinea cruris specimen of early lesions,and 7 out of 10 tinea manus or pedis and 3 out of 4 tinea cruris specimens of old lesions.No hypha was found by CLSM in any of the 10 tinea versicolor specimens,while microscopic examination revealed fungal elements in 8 of them.Neither CLSM nor microscopy revealed fungal elements in lesions from 5 patients with tinea manus or pedis and 5 patients with tinea cruris after treatment with topical bifonazole cream for 2 weeks.Conclusions CLSM shows a good consistency with light microscopy in the examination of early lesions of tinea marnus and pedis as well as tinea croris,and may serve as a valuable tool for clinical diagnosis.