Hidden scabies: diagnosis by polymerase chain reaction

Diagnosis of scabies infection can be difficult as in many cases only few m ites are present on an infected person, and in some cases the skin manifest ations can be subtle or atypical. We describe the use of polymerase chain r eaction (PCR) to amplify Sarcoptes scabiei DNA in a patient presenting with clinically atypical eczema. Cutaneous scales were PCR positive for S. scab iei DNA before, and negative 2 weeks after, therapy. This method facilitate s fast and very sensitive diagnosis of clinically atypical or inapparent sc abies infection and therapy control in severely affected patients and may h elp to identify previously unrecognized scabies cases.