A pediatrician was reviewing the chart of a 26-month old female who had been seen at a local urgent care for sore throat. The patient has been empirically treated with antibiotics based on history and physical examination. The urgent care clinician also cited a modified Centor criteria as justification for starting the empiric antibiotics. She discussed this issue with one of her partners who had noted a similar practice pattern. They identified that it was a new urgent care clinician who had started empiric antibiotics twice. The pediatrician sent a professional e-mail to the urgent care physician providing information that the use of the modified Centor criteria was not appropriate in the < 3 year old age group, and providing a reference to the clinical guidelines. The urgent care provider's reply thanked the pediatrician for the guidance.
Discussion
Group A streptococcal pharyngitis (GAS) is the most common bacterial cause of pharyngitis world-wide. Not only can it cause localized disease, but it can cause invasive disease such as necrotizing fasciitis, pneumonia, and toxic shock syndrome. In children 3 years and older it can cause potential immunological complications such as rheumatic heart disease. GAS is most common in ages 5-15 years, and occurs often in temperate climates, with the highest incidence in winter and early spring.
While GAS is common, its evaluation and management are not simple.
History and physical examination findings cannot adequately discern GAS from the even more common viral causes of infectious pharyngitis (e.g. adenovirus, coxsackie, Epstein-Barr virus, influenza, rhinovirus, etc.) as there is significant overlap. “There needs to be more clarity in the literature regarding the clinical signs and symptoms of viral and bacterial pharyngitis. Symptoms, such as severe sore throat, sudden onset of fever, chills, malaise, nausea, vomiting, abdominal pain, myalgia, headache, tonsillar discharge, tonsillar hypertrophy, tender-enlarged anterior cervical lymphadenopathy, absence of cough, palatal petechia, strawberry tongue, scarlatiniform rash, and uvula edema may be observed in streptococcal infections….Although the presence of cough, runny nose, congestion, hoarseness, mouth ulcers, conjunctivitis, and diarrhea are more suggestive of a viral infection, the clinical symptoms seen in streptococcal infections can also be seen in viral infections.”
A throat culture is the gold standard for diagnosis but can take 1-2 days before results are available, and testing may be limited in some locations. Rapid antigen detection tests (RADT) can be completed in the office and are quick to perform. Cost can still be a problem in resource limited areas.
Learning Point
The appropriate use of RADT along with clinical decision support algorithms and clinical practice guidelines can help clinicians make good decisions regarding patient care. They do need to be applied to the appropriate patient population.
The Centor criteria and McIssac criteria (MCC) are two clinical decision support tests which can be used to help a clinician. Centor scores for patients > 15 years and MCC for patients > 3 years were validated by Fine et. al. The Infectious Disease Society of America (IDSA)has clinical practice guidelines for clinical use.
- Centor criteria (1 point for each criteria present, range is 0-4 points)
- Exudate or swelling of tonsils
- Swollen/tender anterior cervical lymph nodes
- Fever
- Absent cough
- Modified McIssac criteria (modified Centor criteria or MCC, range 0-5 points). The following is added to the Centor criteria
- Ages 3-14 years = +1 point
- Ages 15-44 years = 0 point
- Ages > and = 45 years = -1 point
Children under 3 years are less likely to have GAS and also the immunological sequelae or rheumatic heart disease are rare. They also are more likely GAS carriers and may test falsely-positive. The Centor and MCC were not developed, nor validated, for this age group. Testing is not recommended for this age group, but testing may be considered if there is a close contact such as a sibling or close day-care contact who is positive for GAS.
Children and youth 5-15 years are at highest risk for GAS. The Centor and MCC can be applied for children 3 years and older as the tests are validated in this age group. Children, youth and adults with overt viral symptoms such as presence of cough, rhinorrhea, hoarseness and oralpharyngeal ulcers are usually not recommended to be tested.
All pediatric patients should have a positive RADT and/or culture for GAS before antibiotics are prescribed, as history and physical examination are unreliable indicators of GAS. Positive RADTs do not need a confirmatory throat culture. Negative RADTs do need a confirmatory culture in children and adolescents, but not adults as the incidence of GAS in the adult population is low and sequelae risk is very low in adults.
Appropriate antibiotics should be prescribed that can eradicate the GAS. Penicillin or amoxicillin for 10 days is the common choice. For allergic individuals “…a first generation cephalosporin …for 10 days, or clindamycin or clarithromycin for 10 days, or azithromycin for 5 days.” The IDSA guidelines has a discussion about empiric treatment in adult patients which balances the risk of over- and under-treatment. They state “…exclusion of the diagnosis [of GAS] on the basis of negative RADT results without confirmation by negative culture results is an acceptable alternative to diagnosis….The generally high specificity of RADT should minimize overprescription of antimicrobials for treatment of adults.”
Questions for Further Discussion
1. What causes pharyngitis? A review can be found here
2. How is invasive streptococcal disease treated?
3. What are the common serotypes for Group B streptococcus? A review can be found here
Related Cases
- Disease: Streptococcal Infections | Throat Disorders
- Symptom/Presentation: Infections | Sore Throat
- Specialty:Infectious Diseases | Pathology
- Age: Toddler
To view pediatric review articles on this topic from the past year check PubMed.
Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews. Information prescriptions for patients can be found at MedlinePlus for these topics: Streptococcal Infections and Strep Throat.
To view current news articles on this topic check Google News.
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To view videos related to this topic check YouTube Videos.
Shulman ST, Bisno AL, Clegg HW, et al. 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
Fine AM, Nizet V, Mandl KD. Large-Scale Validation of the Centor and McIsaac Scores to Predict Group A Streptococcal Pharyngitis. Arch Intern Med. 2012;172(11):847-852. doi:10.1001/archinternmed.2012.950
Jaaskelainen J, Renko M, Kuitunen I. Centor scores associated poorly with rapid antigen test findings in children with sore throat. Eur J Pediatr. 2024;184(1):4. doi:10.1007/s00431-024-05863-2
Haynes MA, Temkit M, Kushner I, Hindman DE. Appropriateness of Use of Streptococcal Pharyngitis Testing and Associated Antibiotic Prescribing in the Urgent Care Setting. Clin Pediatr (Phila). 2024;63(12):1691-1697. doi:10.1177/00099228241237908
Eroglu A, Suzan OK, Kolukısa T, et al. The relationship between group A streptococcus test positivity and clinical findings in tonsillopharyngitis in children: systematic review and meta-analysis. Infection. 2025;53(1):427-436. doi:10.1007/s15010-024-02395-7
Leung AKC, Lam JM, Barankin B, Leong KF, Hon KL. Group A beta-hemolytic Streptococcal Pharyngitis: An Updated Review. Curr Pediatr Rev. 2024;21(1):2-17. doi:10.2174/1573396320666230726145436
Author
Donna M. D’Alessandro, MD