Guidance from the Centers for Disease Control and Prevention (CDC) on treating group A Strep pharyngitis recommends antibiotics for any patient (regardless of age) who has a positive rapid antigen test or throat culture. The recommended treatments are penicillin V PO 250 mg QID or 500 mg BID x10 days (250 mg BID or TID x10 in pediatrics), amoxicillin PO 50 mg/kg (maximum 1000 mg) once daily or 25 mg/kg (maximum 500 mg) BID x10 days, or benzathine penicillin G IM 1,200,000 U (600,000 U if <27 kg) x1 dose. In patients with a penicillin allergy, cephalexin, cefadroxil, clindamycin, azithromycin, or clarithromycin can be considered (avoid cephalexin and cefadroxil in patients with immediate type hypersensitivity to penicillin). Empiric therapy is not discussed (likely because this is specific to Group A Streptococcus). There has never been a report of a clinical isolate of group A Strep bacteria that's resistant to penicillin or cephalosporins. However, resistance to azithromycin, clarithromycin, and clindamycin is well known and varies geographically and temporally. [1]
Viral etiologies account for approximately 80% of pharyngitis cases and are typically self-limiting, whereas bacterial infections (particularly those caused by Group A Streptococcus [GAS]; Streptococcus pyogenes) present a greater risk due to potential complications such as acute rheumatic fever, glomerulonephritis, and suppurative sequelae including peritonsillar abscesses. Key clinical scoring systems, including the modified Centor and FeverPAIN criteria, are essential bedside tools to stratify the pretest probability for streptococcal pharyngitis and guide the appropriate use of diagnostics like rapid antigen detection tests (RADTs). While throat cultures remain the diagnostic gold standard with a specificity of 97%-100% and sensitivity of 90%-95%, clinical algorithms should primarily guide initial decisions. The decision to conduct microbiologic testing for a child or adolescent suffering from acute pharyngitis should be informed by both clinical and epidemiological characteristics of their illness. A notable consideration is a history of close contact with confirmed GAS pharyngitis cases or a high community prevalence of GAS infections. Testing is generally unnecessary for patients whose clinical and epidemiological indicators do not suggest GAS as the cause. Using diagnostic studies selectively for GAS not only increases the proportion of true positive results but also helps distinguish between actual infection and mere carrier states. [2], [3]
The modified Centor score was presented with detailed decision thresholds: a score of ≤1 indicates low GAS probability and warrants symptomatic treatment alone, while scores ≥4 suggest an increased risk (up to 53%) and may justify empirical treatment or RADT. The FeverPAIN score showed equivalent or superior utility, particularly in reducing unnecessary antibiotic use, with risk stratifications ranging from 13% to 65% based on total score. For treatment, the preferred antimicrobial regimen for confirmed GAS infections included amoxicillin for 6 to 10 days or a single dose of benzathine penicillin G; cephalexin, clindamycin, or macrolides were reserved for those with penicillin allergy. Notably, the number needed to treat to prevent one sore throat episode at one week was 21. Delayed prescriptions and close follow-up were encouraged in intermediate-risk patients, aligning with UK National Institute for Health and Care Excellence (NICE) guidance, which demonstrated a 27% reduction in antibiotic usage without increased complication rates. This conservative approach may curb resistance and avoid unnecessary treatment in asymptomatic carriers. [2], [3]
Concurrent antibiotic-corticosteroid therapy is generally not indicated for bacterial pharyngitis, as it does not improve pain and might delay recovery. However, steroid use in viral pharyngitis has been found to successfully reduce odynophagia (number needed to treat of 4) without affecting the clinical course. [3]
A 2015 consensus review conducted by Spanish societies of family medicine, infectious diseases, microbiology, pharmacy, and otolaryngology mentions systematic overuse of antibiotics, attributed to overdiagnosis of streptococcal pharyngitis based on non-specific clinical findings, has contributed to increased antimicrobial resistance and unnecessary healthcare costs. The authors recommended using the Centor score to stratify patients by probability of GAS infection. For patients presenting with 2 or more Centor criteria, a rapid antigen detection test (RADT) for GAS was advised as a cost-effective diagnostic method. The RADT demonstrated high specificity (>95%) but variable sensitivity (60%–98%), influencing prescribing behavior; physicians who employed the test prescribed fewer antibiotics. When treatment is indicated based on positive RADT results, the panel endorsed phenoxymethylpenicillin (penicillin V) or amoxicillin as first-line therapy for 8 to 10 days, citing the preserved global susceptibility of GABHS to β-lactams. Macrolides and clindamycin were advised solely in cases of documented penicillin allergy due to growing resistance to macrolides. Amoxicillin-clavulanate was not recommended as initial therapy, given the lack of beta-lactamase production by GAS and its broader spectrum. Additionally, symptomatic management with NSAIDs and topical agents was encouraged; however, the use of corticosteroids remains controversial because their benefit appears to only be for pain relief. [4]
A 2020 Cochrane Review evaluated the effectiveness and safety of corticosteroids as either standalone or adjunctive therapy for sore throat in outpatient settings. This comprehensive analysis incorporated data from nine randomized controlled trials (RCTs) conducted between 1993 and 2017, involving a total of 1,319 participants (950 adults and 369 children), primarily recruited from emergency departments and general practice clinics across five countries. Eight of the nine included trials administered antibiotics to all participants, while one trial incorporated delayed antibiotic prescribin; corticosteroids evaluated included dexamethasone, betamethasone, and prednisone, given via either oral or intramuscular routes. High-certainty evidence demonstrated that corticosteroids significantly increased the likelihood of complete pain resolution at both 24 hours (risk ratio [RR] 2.40; 95% CI, 1.29 to 4.47) and 48 hours (RR 1.50; 95% CI, 1.27 to 1.76), with numbers needed to treat of 5 and 4, respectively. Moderate-certainty evidence showed that corticosteroids accelerated the onset of pain relief by an average of 6 hours (mean difference -5.96 hours; 95% CI, -8.75 to -3.17) and shortened the total duration of pain by approximately 11.6 hours. Notably, no statistically significant differences were observed between groups in terms of adverse events, symptom relapse, or days missed from work or school; however, reporting on adverse outcomes was limited, and only two trials reported pediatric data with inconsistent findings. [5]
A 2017 systematic review and meta-analysis also evaluated 10 RCTs (N= 1,426) on the efficacy and safety of corticosteroids as an adjunctive treatment in patients presenting with sore throat. Eligible trials compared single-dose corticosteroids (most commonly oral dexamethasone up to 10 mg) with placebo or standard care. Patients receiving corticosteroids were twice as likely to experience complete pain relief at 24 hours (RR 2.24; 95% CI 1.17 to 4.29) and had a 50% greater likelihood of being pain-free at 48 hours (RR 1.48; 95% CI 1.26 to 1.75). Corticosteroids also accelerated pain symptom improvement, with a mean 4.8-hour reduction in time to onset of pain relief (95% CI -1.9 to -7.8) and an 11.1-hour reduction in time to complete relief (95% CI -0.4 to -21.8). No significant effect was found on recurrence/relapse of symptoms, days missed from work/school, or the chance of taking antibiotics (in patients given prescription with instructions to take antibiotic if unimproved or worse). [6]