Utility of Streptococcal Rapid Antigen Detection Test in Children with Acute Pharyngitis

Lim, Ki Hyun; Choi, Woo Jin; Kim, Mi Jin; Kim, Young Ho; Jung, Ji A; Yang, Seung; Hwang, Il Tae; Lee, Hae Ran

Abstract

PURPOSE: The purpose of this study was to evaluate the utility of rapid antigen detection test for group A streptococci in children with acute pharyngitis.
METHODS
Seventy children with acute pharyngitis enrolled the study, who visited the Department of Pediatrics, Kangdong Sacred Heart Hospital, Hallym Medical Center from September 2004 to August 2005. The presence of clinical features such as tonsillar exudates, fever, scarletiniform rash and previous antibiotic use were evaluated and throat swab culture, rapid antigen detection test for group A Streptococci, CBC, ASO, and CRP were performed.
RESULTS
Among 70 children with acute pharyngitis, the prevalence of group A beta-hemolytic Streptococcus by throat swab culture and rapid antigen detection test was 14(20.0 %) and 22(31.4%), respectively. The sensitivity of the rapid antigen detection test was 78.6 %, specificity was 80.4%, the positive predictive value was 50.0% and the negative predictive value was 93.8%. The positivity of the throat swab culture and rapid antigen detection test showed no signigicant differences according to the presence of the clinical symptoms except scarletiniform rash. Laboratory data such as CBC, ASO or CRP proved not valuable to predict the positivity of the throat swab culture and/or rapid antigen detection test for group A Streptococcus. There was a tendency of negative throat swab culture and positive rapid antigen detection test in cases of previous antibiotic use.
CONCLUSION
The rapid antigen detection test can be a useful diagnostic tool for early detection of the group A Streptococcus in children with acute pharyngitis and can be helpful for the clinician to reduce the inappropriate use of antibiotics.