Effectiveness of Cytochrome c Oxidase Subunit 1 Gene Nested Polymerase Chain Reaction Compared to Dermoscopy or Microscopy Alone for the Detection and Diagnosis of Sarcoptes scabiei var. hominis Infection

ABSTRACT

Background@#While microscopy (MS) evaluation of skin scrapings has a 100% positive predictive value and specificity by definition for scabies diagnosis, it has low sensitivity. Dermoscopy (DS) has not yet been widely accepted for diagnosis, and long-term clinician training is required. @*Objective@#To evaluate the diagnostic validity of cytochrome c oxidase subunit 1 (cox1) gene nested polymerase chain reaction (PCR) as an adjunctive method for diagnosing scabies. @*Methods@#This was a prospective, single institution study, conducted on a total of 302 skin lesions from 50 patients suspected of scabies at Kangdong Sacred Heart Hospital in Seoul, Korea. DS, MS, and cox1 nested PCR were performed on all patients. @*Results@#Of the 302 lesions, 145 (48.0%) were obtained at first visit and 157 (52.0%) were identified in the course of follow-up visits after treatment. For all lesions, DS and MS sensitivity levels were 55.9% (73/136) and 55.2% (75/136), respectively, with cox1 gene nested PCR considered as 100%. The results of DS and MS identification showed no difference between each other and showed significant difference from that of cox1 gene nested PCR. @*Conclusion@#Nested PCR detecting cox1 may be prospectively used to comprehensively diagnose lesions of scabies in clinical practice.