From the Guidelines
For suspected strep throat, a thorough history and physical examination should be performed, and diagnosis should be confirmed by laboratory tests, such as throat culture or rapid antigen detection test (RADT), as recommended by the Infectious Diseases Society of America 1.
Key Components of History and Physical Examination
- Onset and duration of symptoms, particularly sore throat, fever, difficulty swallowing, and absence of cough or rhinorrhea
- Sudden onset of symptoms, fever (typically >101°F), tonsillar exudates, tender anterior cervical lymphadenopathy, and absence of cough—these comprise the Centor criteria which help determine likelihood of Group A Streptococcal pharyngitis
- Exposure to individuals with confirmed strep throat, previous episodes of strep infections, and any history of rheumatic fever or post-streptococcal glomerulonephritis
- Attempted home remedies or over-the-counter medications
Treatment Recommendations
- Penicillin V potassium (250-500mg orally twice daily for 10 days) remains first-line therapy, with amoxicillin (50mg/kg once daily, max 1000mg, for 10 days) as an alternative due to better taste for children 1
- For penicillin-allergic patients, recommend cephalexin (if no anaphylactic reaction history) or macrolides like azithromycin (500mg on day 1, then 250mg daily for 4 days) 1
- Accurate diagnosis and complete antibiotic treatment are essential to prevent complications like rheumatic fever and peritonsillar abscess
Importance of Accurate Diagnosis and Treatment
- Acute pharyngitis is one of the most frequent illnesses for which pediatricians and other primary care physicians are consulted, but only a relatively small percentage of patients have GAS pharyngitis 1
- Antimicrobial therapy is not indicated for the large majority of chronic streptococcal carriers, but eradication of carriage may be desirable in certain situations, such as during a community outbreak of acute rheumatic fever or invasive GAS infection 1
From the Research
Strep HPI
- The diagnosis of streptococcal pharyngitis is typically made based on clinical presentation and laboratory testing, with common signs and symptoms including sore throat, fever, tonsillar exudates, and cervical adenopathy 2.
- The modified Centor score can be used to help physicians decide which patients need no testing, throat culture/rapid antigen detection testing, or empiric antibiotic therapy 2, 3.
- Available diagnostic tests include throat culture and rapid antigen detection testing, with throat culture considered the diagnostic standard 2.
- Penicillin and amoxicillin are first-line antibiotics for the treatment of streptococcal pharyngitis, with a recommended course of 10 days 2, 4.
- First-generation cephalosporins are recommended for patients with nonanaphylactic allergies to penicillin 4.
- Cephalexin has been shown to be more effective than penicillin in the treatment of group A beta-hemolytic streptococcal throat infections in children 5.
- Azithromycin has been compared to penicillin V for the treatment of acute group A streptococcal pharyngitis, with similar clinical efficacy but lower bacteriologic eradication rates 6.
Treatment Failure and Resistance
- Increased group A beta-hemolytic streptococcus (GABHS) treatment failure with penicillin has been reported 2.
- There is significant resistance to azithromycin and clarithromycin in some parts of the United States 4.
- The combined treatment failure rate of clinical relapse plus asymptomatic bacteriologic failure was 19% in the penicillin treatment group and 10% in the cephalexin treatment group 5.
Prevention and Management
- Tonsillectomy is rarely recommended as a preventive measure, with thresholds of seven episodes of streptococcal pharyngitis in 1 year, five episodes in each of the past 2 years, or three episodes in each of the past 3 years commonly used for considering surgery 4.
- The optimal clinical management of adults with sore throat depends on both the clinical probability of a group A streptococcal infection and clinical judgments that incorporate individual patient and practice circumstances 3.