Review of the Risk Assessment and Treatment of Group A Streptococcal (GAS) Pharyngitis

Pharyngitis is one of the most common indications for pursuing treatment in the outpatient setting.¹ Although most sore throats are viral and resolve on their own without treatment, pharyngitis is one of the most common diagnoses associated with an antibiotic prescription.¹ Pharyngitis caused by group A Streptococcus (GAS; Streptococcus pyogenes) is more commonly known as strep throat.² It is the most common bacterial cause of acute pharyngitis.³ It is estimated that strep throat accounts for 5.2 million outpatient visits each year among those younger than 65 years.⁴ Although most sore throats are caused by viruses and do not require antibiotics, strep throat occurs in approximately 10% of adults and 30% of children.⁵ Despite the prevalence of viral sore throat, 72% of adults and 56% of children with pharyngitis receive antibiotics.⁶ Appropriate diagnosis and treatment of GAS pharyngitis are important to prevent complications, minimize transmission, and return to everyday activities.³

Symptoms of GAS pharyngitis typically include fever, pain with swallowing, and rapid onset of sore throat symptoms.² Concomitant symptoms of sore throat with cough, runny nose, hoarseness, and conjunctivitis suggest a viral etiology and are the most common cause of pharyngitis in all age groups.^2,5 Antibiotic treatment is indicated for pharyngitis caused by GAS; therefore, accurate diagnosis and treatment are important to avoid unnecessary antibiotic exposure, overuse, and resistance.³

Clinical judgment alone is unreliable to diagnose pharyngitis caused by GAS, and clinical scoring systems have been developed to assist in determining the probability of a positive GAS throat culture result based on standard criteria.³ In 2025, the Infectious Diseases Society of America released an update on assessing the risk of GAS pharyngitis by utilizing clinical scoring systems for individuals older than 3 years.³ It should be noted that the guideline proposed a conditional recommendation with very low certainty of evidence as a result of the limitations in comparative studies but noted that the balance of benefits and harms supports implementing a clinical scoring system to evaluate patients with sore throat in clinical practice.^3,7

Individuals at high risk, such as those with household exposure to GAS, history of rheumatic fever, or symptoms of local or systemic GAS infections, should be strongly considered for testing for GAS pharyngitis.³ Clinical scoring systems should be utilized to identify individuals older than 3 years with a low probability of GAS pharyngitis in whom further testing is unlikely to be helpful or change clinical management.³ Utilizing scoring systems with favorable negative predictive values would decrease unnecessary testing with rapid antigen detection tests, nucleic acid amplification tests, and/or throat culture and avoid unnecessary antibiotics in individuals with a low likelihood of GAS infections.³ Examples of clinical scoring systems to predict GAS pharyngitis include Centor, McIsaac, and FeverPAIN.³ Centor and McIsaac scoring systems have been validated and have nearly the same clinical scoring features, including presence of fever, tonsillar exudate or enlargement, tender and enlarged anterior lymph nodes, and the absence of cough, except for the addition of age in the McIsaac system.³ Of note, as of the guideline update, there has been no documented evidence to compare the FeverPAIN scores with clinical judgment.³ The guidelines indicate a lack of evidence favoring one scoring system over the other, suggesting clinicians and patients may favor those that do not utilize laboratory testing.³ Those with greater points on the scoring systems have a higher risk of positive results for detection of GAS.³

Treatment of GAS pharyngitis requires an antibiotic with activity against S pyogenes.² There has been no documented resistance of GAS to penicillin or cephalosporins; therefore, penicillin and amoxicillin are the drugs of choice for treating GAS pharyngitis,² although amoxicillin may be preferred due to less frequent daily dosing. Overly broad-spectrum cephalosporins, such as cefdinir and cefpodoxime, are costly and unnecessary for treatment of GAS alone and may increase the risk of antibiotic-related adverse effects and antibiotic resistance.⁸ Cephalexin or cefadroxil are preferred in those with a non–immediate-type penicillin allergy.^2,8 Those with immediate-type hypersensitivity to penicillin should be treated with clindamycin, clarithromycin, or azithromycin.^2,8

All antibiotics are recommended for 10 days, with the exception of azithromycin, which is given for 5 days.^2,8 Azithromycin, clarithromycin, and clindamycin resistance has been documented and varies by geographical location; therefore, local susceptibility patterns should be followed before prescribing these agents.² The risk of transmitting GAS decreases after at least 12 to 24 hours of an appropriate antibiotic.² Tetracyclines and trimethoprim-sulfamethoxazole are not recommended for treatment of GAS pharyngitis due to resistance and/or clinical failure.⁸ Fluoroquinolones are costly, have a broad spectrum of activity, and are also not routinely recommended.⁸

Because the diagnosis of GAS based on clinical judgment alone is inaccurate, appropriate diagnosis of GAS pharyngitis is imperative to prevent unwarranted antibiotic prescriptions as well as the cost and potential adverse effects.³ Appropriate antibiotic prescribing and identification of those who require treatment for GAS are crucial to prevent suppurative complications such as peritonsillar abscess, cervical lymphadenitis, mastoiditis, or more invasive disease as well as rheumatic fever.^2,3 When patients present with sore throat, utilizing clinical scoring systems to identify those at low risk for pharyngitis caused by GAS will decrease the use of unnecessary testing and antibiotic exposure while also decreasing the cost, patient inconvenience, and risk of antibiotic resistance.^1,3

References

1. Fleming-Dutra KE, Hersh AL, Shapiro DJ, et al. Prevalence of inappropriate antibiotic prescriptions among US ambulatory care visits, 2010-2011. JAMA. 2016;315(17):1864-1873. doi:10.1001/jama.2016.4151

2. Clinical guidance for group A streptococcal pharyngitis. Centers for Disease Control and Prevention. November 18, 2025. Accessed February 24, 2026. https://www.cdc.gov/group-a-strep/hcp/clinical-guidance/strep-throat.html

3. Linder JA, Watson ME, Wessels MR, et al. 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. Clin Infect Dis. Published online December 4, 2025. doi:10.1093/cid/ciaf668

4. Group A strep disease surveillance and trends. Centers for Disease Control and Prevention. July 8, 2024. Accessed February 24, 2026. https://www.cdc.gov/group-a-strep/php/surveillance/index.html

5. About strep throat. Centers for Disease Control and Prevention. January 15, 2026. Accessed February 24, 2026. https://www.cdc.gov/group-a-strep/about/strep-throat.html

6. Lewnard JA, King LM, Fleming-Dutra KE, Link-Gelles R, Van Beneden CA. Incidence of pharyngitis, sinusitis, acute otitis media, and outpatient antibiotic prescribing preventable by vaccination against group A Streptococcus in the United States. Clin Infect Dis. 2021;73(1):e47-e58. doi:10.1093/cid/ciaa529

7. Fitch J. IDSA recommends use of scoring systems to guide testing for group A streptococcal pharyngitis. Contemporary Pediatrics. October 15, 2025. Accessed February 24, 2026. https://www.contemporarypediatrics.com/view/idsa-recommends-use-of-scoring-systems-to-guide-testing-for-group-a-streptococcal-pharyngitis

8. Shulman ST, Bisno AL, Clegg HW, et al; Infectious Diseases Society of America. Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America. Clin Infect Dis. 2012;55(10):e86-e102. doi:10.1093/cid/cis629