Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
PLoS Negl Trop Dis. 2020 Apr 7;14(4):e0008229. doi: 10.1371/journal.pntd.0008229. eCollection 2020 Apr.
Scabies is a highly contagious parasitic disease associated with long-term residence in nursing homes, and it is a public health burden worldwide. However, atypical skin manifestations are frequent and the widely used diagnostic test based on microscopic examinations has limited sensitivity. We evaluated the diagnostic value of polymerase chain reaction (PCR) from skin scraping in patients with suspected scabies. Adult patients with suspected scabies, unrelated diseases or healthy volunteers were enrolled at a tertiary hospital, in Seoul, South Korea, from December 2017 through October 2018. We classified participants based on the consensus criteria established by the International Alliance for the Control of Scabies in 2018; confirmed (microscopic mite detection), clinical (scabies burrow or typical lesions with two history features including itch and close contact with scabies patients), suspected scabies (typical lesion with one history feature or atypical lesion with two history features), or no scabies. PCR was performed on the skin scrapings to target the cytochrome c oxidase subunit 1 (cox1) gene of Sarcoptes scabiei. A total of 47 participants, 33 with suspected scabies, 10 with unrelated diseases, and 4 healthy volunteers were enrolled. Of the 33 patients, 22 were classified as confirmed scabies, 2 as clinical scabies, 6 as suspected scabies, and 3 as no scabies. The sensitivities of the microscopic examination were 100%, 92%, and 73% in confirmed scabies; confirmed and clinical scabies; and confirmed, clinical, and suspected scabies, respectively (p = 0.006). The sensitivities of PCR were 86%, 83%, and 80% in confirmed scabies; confirmed and clinical scabies; and confirmed, clinical, and suspected scabies, respectively (p = 0.59). The specificity of the scabies PCR in the no scabies control was 100% (95% CI = 80-100).PCR testing for scabies may be helpful in the improvement of sensitivity for the diagnosis of scabies by clinical criteria.
疥疮是一种与长期居住在养老院有关的高度传染性寄生虫病，也是全球范围内的公共卫生负担。然而，其不典型皮肤表现较为常见，且广泛应用的基于显微镜检查的诊断检测方法的敏感性有限。我们评估了聚合酶链反应（PCR）从疑似疥疮患者的皮肤刮片中检测的诊断价值。2017 年 12 月至 2018 年 10 月，我们在韩国首尔的一家三级医院招募了疑似疥疮的成年患者、无相关疾病或健康志愿者。我们根据 2018 年国际疥疮控制联盟制定的共识标准对参与者进行分类；确诊（显微镜下发现螨虫）、临床（疥疮隧道或具有两个包括瘙痒和与疥疮患者密切接触在内的病史特征的典型病变）、疑似疥疮（具有一个病史特征或两个病史特征的不典型病变）或无疥疮。对皮肤刮片进行 PCR 检测，以靶向疥疮的细胞色素 c 氧化酶亚基 1（cox1）基因。共有 47 名参与者，其中 33 名患有疑似疥疮，10 名患有无关疾病，4 名健康志愿者。在 33 名患者中，22 例被归类为确诊疥疮，2 例为临床疥疮，6 例为疑似疥疮，3 例为无疥疮。在确诊疥疮中，显微镜检查的敏感性分别为 100%、92%和 73%；确诊和临床疥疮；以及确诊、临床和疑似疥疮（p=0.006）。PCR 的敏感性分别为 86%、83%和 80%在确诊疥疮中；确诊和临床疥疮；以及确诊、临床和疑似疥疮（p=0.59）。在无疥疮对照组中，疥疮 PCR 的特异性为 100%（95%CI=80-100）。PCR 检测疥疮可能有助于提高临床标准诊断疥疮的敏感性。
