Acute pharyngitis is a common illness occurring in children and adolescents. Group A beta-hemolytic streptococcus (GABHS) is the most frequent cause of acute pharyngitis, accounting for 15 – 30 percent of cases in children, while the remaining 70 – 85 percent can be attributed to a number of viruses and non-streptococcal bacteria.¹ In most cases, acute pharyngitis is both benign and self-limiting. However, group A streptococcal infection is an illness for which antimicrobial therapy is indicated.²

Appropriate diagnosis by testing for and antibiotic treatment of group A streptococcal infections is necessary to prevent suppurative sequelae such as peritonsillar or retropharyngeal abscess, cervical lymphadenitis, mastoiditis, otitis media and sinusitis³, and most importantly, preventing acute poststreptococcal glomerulonephritis and acute rheumatic fever.⁴ The clinical manifestations of GABHS and non-streptococcal pharyngitis have an extensive overlap, thus requiring either a Rapid Antigen Detection Test (RADT) and/or throat culture for confirmation of the definitive diagnosis and appropriate subsequent treatment.⁵ Without a definitive diagnosis, providers are more likely to over-treat with antibiotics rather than properly diagnose and treat group A streptococcus pharyngitis.

A 12-month retrospective study – from July 2006 to June 2007 – of Medi-Cal fee-for-service (FFS) recipients was conducted to determine whether children, between 2 and 18 years of age, diagnosed with acute pharyngitis, tonsillitis or streptococcal sore throat, were given a strep test along with antibiotic medications. The study, designed using specific diagnosis codes, procedural codes and criteria from “Appropriate Testing of Children with Pharyngitis” by the National Committee for Quality Assurance (NCQA) for HEDIS 2008,⁶ yielded the following data:

• 11,362 Medi-Cal FFS recipients were diagnosed with pharyngitis and received a prescription for an antibiotic in the first eligible episode during the study period.
• Only 21 percent (2357) of patients received a streptococcal test in the initial episode diagnosed and a prescription for an antibiotic medication.
• Over 81 percent (9183) received penicillin or its congeners, which are the recommended antibiotics for treating GABHS.

The Medi-Cal data shows that about 80 percent of patients received antibiotics without being given a strep test in the initial episode. It is important to recognize that due to an extensive overlap of clinical manifestations of acute pharyngitis by group A streptococcal and non-streptococcal infection, current diagnosis and treatment guidelines indicated by Infectious Diseases Society of America (IDSA) and the American Academy of Pediatrics advocate a definitive diagnosis by either a RADT and/or throat culture⁷ (see algorithm chart). A negative RADT result should be confirmed with a throat culture result. Both tests are reimbursable by Medi-Cal. Antimicrobial therapy is indicated if the presence of GABHS is confirmed by either RADT or by culture.

Since the great majority of pharyngitis episodes (about 70 – 80 percent of cases) are not caused by group A streptococci, empiric antibiotic treatment will result in significant over treatment. Overuse of unwarranted antibiotic treatment and/or usage of broad-spectrum antibiotics can lead to the development of antibiotic resistance. Medi-Cal recommends providers follow IDSA guidelines when treating children with pharyngitis.

If GABHS is confirmed, the gold standard for treatment of GABHS pharyngitis is narrow-spectrum penicillin. Amoxicillin is an appropriate alternative due to its similar spectrum of coverage as well as its better palatability in the suspension form. If compliance is an issue, one dose of benzathine penicillin G via intramuscular injection can be given. For patients with allergies to penicillin, but without cross-sensitivity, first-generation cephalosporins such as cephalexin are suitable alternatives. Erythromycin is the first-line agent for patients with anaphylactic reactions to penicillin or cross-sensitivity to cephalosporins. For erythromycin-resistant group A streptococcal infections, clindamycin is an appropriate alternative treatment choice. Broad-spectrum antibiotics such as fluoroquinolones and third-generation cephalosporins are not recommended due to higher costs, a propensity for increasing antibiotic resistance in a broader range of bacterial pathogens, and for the most part, they are unwarranted due to lower-cost alternatives.

References

1. Bisno, Alan. Acute Pharyngitis. NEJM 2001; 344(3):205-211


2. Bisno, Alan et al. Diagnosis and Management of Group A Streptococcal Pharyngitis: A Practice Guideline. Clin Infect Dis 1997; 25:574-83


3. Ruff, Joel, MD. Chapter VI.9 Oral and Upper Respiratory Infections. Case Based Pediatrics For Medical Students and Residents. 2002


4. Schwartz, Benjamin et al. Pharyngitis – Principles of Judicious Use of Antimicrobial Agents. Pediatrics 1998; 101:171-174


5. Schwartz, Benjamin et al. Pharyngitis – Principles of Judicious Use of Antimicrobial Agents. Pediatrics 1998; 101:171-174


6. National Committee for Quality Assurance (NCQA). HEDIS 2008; 2:89-91


7. www.guideline.gov. National Guideline Clearinghouse Acute Pharyngitis. Institute for Clinical Systems Improvement - Private Nonprofit Organization. 1998 Aug (revised 2005 May). 33 pages. NGC:004347