Abstract
PurposePrediction rules to identify group A streptococcal pharyngitis (GAS) in adults have been well validated, but may not be applicable to the pediatric population. The purpose of our study is to establish pediatric specific clinical prediction criteria (CPC) to identify children with group A streptococcal pharyngitis.MethodsThroat cultures were obtained on a consecutive sample of 1022 children ages 18 years and younger presenting to an academic pediatric primary care practice, from November 2003 to August 2004. Informed consent was obtained and children were enrolled when the attending physician ordered a rapid GAS test. Presenting symptoms and clinical examination findings were collected prospectively at the time of throat culture. The clinical prediction criteria were developed using both univariate analysis and multivariate logistic regression.Results352 (34%) of the 1022 children presenting were positive for GAS by throat culture. Children were divided into three groups according to age (0-2, 2-12, and 12-18 years). Five (9%) of the 55 children less than two years of age and 50 (21%) of the 240 children ages 12-18 years were positive for GAS. These two groups were not included in development of our CPC. The 2-12 year old group included 723 children, of whom 297 (41%) were positive for GAS. We developed a CPC unique for this age group. A finding of scarletina rash had a sensitivity of 12%, specificity of 98%, and a positive predictive value (PPV) of 79%, thus prompting treatment for GAS without further testing. For patients without scarletina rash, the following coefficients/predictors apply: 0.4 sore throat/difficulty swallowing, 0.38 lymphadenopathy, 0.45 pharyngeal erythema, and 0.38 for palatal petechiae. Based on these coefficients, each predictor will be assigned a value of 1, and the resulting risk scoring system for GAS is 0 features present P = 9.4%, 1 feature 18.1-20.3%, 2 features 32.1-36.1%, 3 features 51.3-54.7%, and all 4 features 72%.ConclusionThese findings support establishment of pediatric specific criteria for diagnosis of GAS pharyngitis.