Sight the Mite: A Meta-Analysis on the Diagnosis of Scabies

Abstract

This meta-analysis was performed to assess the efficacy of the diagnostic tests for scabies infections that are currently in wide use. Scabies is most commonly diagnosed through clinical presentations; however, due to the wide array of symptoms, diagnosis is difficult. The most commonly used diagnostic test is skin scraping. However, this test relies on correctly selecting the site of mite infection for sampling. Due to the mobile nature of a live parasitic infection, the mite can often be missed based on its current location within the skin. The goal of this paper is to determine if a gold standard confirmatory test exists for the diagnosis of scabies by comparing Skin Scraping, Adhesive Tape, Dermoscopy, and PCR tests. Medline, PubMed, and Neglected Tropical Diseases databases were utilized in a literature review. Eligible papers were papers published in or after the year 2000, published in the English language, and mainly focused on the diagnosis of scabies. At the time of this meta-analysis, scabies is mostly diagnosed through a correlation of clinical symptoms in conjunction with diagnostic tests such as dermoscopy (sensitivity: 43.47%, specificity: 84.41%), adhesive tape tests (sensitivity: 69.56%, specificity: 100%) and PCR antigen detection (37.9% sensitivity, specificity: 100%). Due to a scarcity of data in the literature, the diagnostic efficacy of other diagnostic tests is difficult to assess. Overall, the efficacies of the tests analyzed vary depending on how similar scabies is to other skin disorders, how challenging it is to get a usable sample and the price and accessibility of essential tools. There is a need for standardized national diagnostic criteria to increase the diagnostic sensitivity of scabies infection.