Overview of 2025 Clinical Practice Guideline Update by the Infectious Diseases Society of America on Group A Streptococcal (GAS) Pharyngitis: Risk assessment using clinical scoring systems in children and adults

Abstract This publication represents the first part of an update to the clinical practice guideline on the diagnosis and management of group A streptococcal (GAS) pharyngitis, developed by the Infectious Diseases Society of America (IDSA). Diagnosis of GAS pharyngitis by clinician judgement alone is unreliable, and universal testing incurs cost and inconvenience for individuals at low risk of having GAS infection. Clinical scoring systems have been used to quantify the probability of a positive GAS throat culture based on standardized criteria such as the presence of fever; tonsillar enlargement or exudate; tender and enlarged anterior cervical lymph nodes; and the absence of cough. The goal of this manuscript is to review the evidence and provide a recommendation as to whether a scoring system should be used to decide which patients should have a GAS diagnostic test (i.e., rapid antigen test (RADT), molecular method, and/or throat culture) performed. We performed a systematic review of randomized and non-randomized studies that compared the use of a clinical scoring system to clinician judgement alone in predicting the result of a throat culture. Evidence from studies in children and adults suggests the diagnostic accuracy is comparable or slightly higher using a scoring system compared to clinician judgement alone. Although the studies are limited due to small size, lack of uniformity in outcome measures, and incomplete data, the consensus of the panel is that the balance of benefits and harms favors incorporation of a clinical scoring system as part of the evaluation of patients with sore throat and suspected GAS pharyngitis.