A new diagnostic technique for tinea incognito: In vivo reflectance confocal microscopy. Report of five cases Enver Turan 1 , Asli Turgut Erdemir 2 , Mehmet Salih Gurel 2 and Nurdan Yurt 2 1 Department of Dermatology, Faculty of Medicine, University of Harran, 63200-Sanliurfa, Turkey and 2 Department of Dermatology, Istanbul Education and Research Hospital, Istanbul, Turkey Background/purpose: In vivo confocal laser scanning micros- copy (CLSM) is a modern non-invasive method for investiga- tion of the skin that allows real-time visualization of individual cells and subcellular structures with the highest resolution imaging comparable to the routine histopathology. Our aim was to demonstrate the potential of CLSM for non-invasive diagnosis of difficult tinea incognito cases. Methods: Clinically atypical lesions in five cases of tinea incognito due to dermatophyte spp. were demonstrated using reflectance confocal laser scanning microscopy (RCM), parallel to KOH preparation and fungal culture of skin scrapings per- formed in the same patients. Results: The morphological features characteristic for tinea incognito, namely linear branched hyphae in the intercellular area of the stratum corneum, were readily detectable by means of CLSM. In vivo tissue imaging were performed at three differ- ent wavelengths (785, 658, 445 nm) and the best images of fungal elements were obtained at 445 nm. All of our five cases had similar reflectance confocal microscopical findings. Conclusions: Our findings suggest the potential of CLSM as a non-invasive tool for the diagnosis of tinea incognito having atypical clinical appearance. Although at present the reflec- tance confocal microscopy cannot replace the current diagnos- tic standards for tinea incognito, it may be successfully used as in vivo non-invasive screening tool to facilitate the diagnosis and point to the need for further investigation of the patient. Key words: skin disease – confocal microscopy – dermatomy- coses Ó 2012 John Wiley & Sons A/S Accepted for publication 26 April 2012 D ERMATOPHYTE SPECIES are the most frequent causative fungal agent in dermatomycoses (1). The diagnostic methods include KOH microscopic examination and fungal culture of material obtained by skin scrapings and histo- pathological examination of skin biopsies (2). KOH preparation is relatively time-consuming and can yield incorrect results due to sampling error. The fungal culture and histopathological examination cause significantly longer delays in diagnosis (2, 3). In contrast, in vivo reflectance confocal microscopy (RCM) provides a high-res- olution and real-time imaging for the diagnosis of skin lesions (4). RCM may be a practical and reliable diagnostic method for the superficial fungal infections compared with the conven- tional methods. Report of five cases Five cases were admitted to the dermatology clinic with lesions having bizarre clinical appearance (Fig. 1). Six lesions of five patients were examined with RCM for further evalua- tion of skin lesions. RCM examination was made using a multilaser RCM (VivaScope ® 1500, Lucid inc, Rochester, NY, USA). In all cases, linear branched hyphae were observed in the intercellular area of the stratum corneum. Compared to the background, hyphae appeared as refractile, bright, linear structures (Figs. 2 and 3). RCM examination was taken approxi- mately 15 min. Tinea incognito was diagnosed by RCM in all five cases. They were treated with systemic and topical antimycotic agents, and all lesions healed completely in the follow- up period (Table 1). Discussion Dermatophyte infection that is modified by sys- temic or topical corticosteroid treatment is known as tinea incognito, which causes diffi- culty in diagnosis (5). Suppression of cellular 1 Skin Research and Technology 2012; 0:1–5 Printed in Singapore Á All rights reserved doi: 10.1111/j.1600-0846.2012.00615.x © 2012 John Wiley & Sons A / S Skin Research and Technology