Scabies incognito: diagnostic value of dermoscopy-guided microscopic examination

Background Dermoscopy is a noninvasive device that facilitates visualization of the details of skin layers down to the upper dermal papillary layer. It can aid in the diagnosis of classic scabies; however, studies are limited as regards the value of dermoscopy versus microscopy in the diagnosis of scabies incognito. Objective The aim of this study was to assess the possible added diagnostic value of dermoscopy-guided scraping in diagnosing scabies incognito versus scraping and microscopic examination. Patients and methods Scraping with direct light microscopic examination procedure under dermoscopic guidance versus without dermoscopy was evaluated in patients with suspected scabies incognito, with photographic documentation, and assessment of the timing and results of each technique. Results Dermoscopy-guided scraping showed a sensitivity of 92.6 versus 44.4% for scrapings without dermoscopy. Duration until reaching diagnosis was significantly shorter in dermoscopy-guided scraping. Conclusion Dermoscope is an efficient and simple diagnostic tool that allows confirmation of diagnosis in cases of scabies incognito and minimizing the duration to reach diagnosis if combined with guided scraping and microscopic examination.