The challenge of Diagnosing Common Dermatomycosis by Reflectance Confocal Microscopy

Background: Traditional detection of fungal infections of the skin relies on microscopy techniques or fungal culture. Currently, reflectance confocal microscopy (RCM) has been widely applied to assist the diagnosis of commondermatomycosis with advantages of non-invasiveness, celerity, real time, and repeatability. Materials and Methods: A total of 478 clinically suspected dermatomycosis patients were enrolled in this study including 148 cases of tinea manus and pedis, 188 cases of tinea corporis and cruris and 142 cases of pityriasis versicolor. RCM examination was performed to image the lesions. Aim: This study aimed to summarize the image characteristics of in vivo RCM examination on common dermatomycosis and retrospectively evaluate its accuracy as compared with microscopy results. Furthermore, we attempted to tackle the challenges of RCM diagnosis on common dermatomycosis. Results: Based on RCM images, 231 of 478 (48.3%) patients were detected with hyphae. Among all RCM confirmed cases, 58 out of 148 (39.2%) were tinea manus and pedis, 145 out of 188 (77.1%) were tinea corporis and cruris, and 28 out of 142 (19.7%) were pityriasis versicolor. The remaining patients (51.7%) could not be diagnosed by the dermatologist according to RCM. Hyphae structures were primarily identified during diagnoses of dermatomycosis by RCM. Conclusions: RCM is a novel optical imaging technique that confers high-resolution images of fungi. RCM has certain advantages in the diagnosis of tinea manus and pedis. RCM is not suitable for the diagnosis of pityriasis versicolor.