Presentation
The classic manifestation of streptococcal pharyngitis includes fever, sore throat, tonsillar exudates, and tender anterior cervical adenopathy. However, not all of these features may be present. Other common symptoms can include headache, nausea, vomiting, fatigue, myalgia, and abdominal pain. As well, physical examination may reveal palatal petechia or a scarlatiniform rash.
Incubation period: approximately 2 - 5 days
pitfalls
Features of viral pharyngitis (e.g., cough, coryza, hoarseness, diarrhea) do NOT usually occur in patients with strep throat. However, the presence of a single viral feature does NOT rule out streptococcal pharyngitis.
Frank tonsillar exudates are NOT pathognomonic of a streptococcal throat infection. Other pathologies (e.g., infectious mononucleosis, adenovirus pharyngitis) can also present with exudates.
Children less than three years old do NOT usually present with classic symptoms but rather nonspecific manifestations such as rhinitis, low-grade fever, and decreased appetite.
Photos taken from individuals with streptococcal pharyngitis
Suggestive Features
Streptococcal Pharyngitis | Viral Pharyngitis |
Exudative tonsillopharyngitis | Conjunctivitis |
Tender anterior cervical adenopathy | Rhinorrhea ± nasal congestion |
Fever | Cough |
Scarlet fever (e.g., rash, strawberry tongue) | ​Hoarseness |
​ | Oropharyngeal vesicles or ulcers |
​ | Diarrhea |
Evaluation
Unfortunately, there isn't a combination of signs and symptoms that can preclude the need for microbiologic testing. When there is sufficient clinical suspicion of a streptococcal infection, the diagnosis should be confirmed with microbiologic testing (e.g., throat culture, rapid antigen detection test). In the pediatric age group, a negative rapid antigen detection test should be followed up with a culture. With few exceptions, a follow up culture is not necessary in adults.
pitfalls
Clinical scoring systems (e.g., Centor criteria, McIssac) are neither sufficiently sensitive nor specific to establish a diagnosis. They cannot be used in placed of testing to determine the need for therapy.
False-negative tests (both RADT and culture) can occur due to inadequate sampling.
False-positive tests (both RADT and culture) can occur in individuals colonized with group A streptococcus.
Management
The recommended antibiotic therapy for treating streptococcal pharyngitis is a ten day course penicillin. Antibiotic treatment prevents the spread of infection and the development of complications. It is also important to recommend supportive measures. Recovery usually occurs within three to five days. Contagiousness decreases significantly 12 hours following the first dose of antibiotics.
pitfalls
There is increasing resistance to macrolides (e.g., azithromycin).
Eradication of S. pyogenes does not occur in a significant proportion of patients.
Common supportive measures |
Maintaining adequate hydration |
Analgesic/antipyretic therapy |
Lozenges and throat drops |
Rest |
Soft foods (e.g., soup, smoothies, mashed potatoes) |
Complications
Streptococcal pharyngitis can lead to further morbidity if the infection spreads or immunologic phenomena develop. The table below is not an all-inclusive list of suppurative and non-suppurative complications.
Suppurative | Nonsuppurative |
Peritonsillar cellulitis/abscess | Acute rheumatic fever |
Otitis media | Poststreptococcal glumerulonephritis |
Sinusitis | Reactive arthritis |
Bacteremia | Scarlet Fever |
Meningitis | Streptococcal toxic shock syndrome |
Impetigo/erysipelas | ​ |
Necrotizing fasciitis | ​ |
Video Lecture
References
Shulman ST, Bisno AL, Clegg HW, Gerber MA, Kaplan EL, Lee G, Martin JM, Van Beneden C; 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 Nov 15;55(10):e86-102. doi: 10.1093/cid/cis629. Epub 2012 Sep 9. Erratum in: Clin Infect Dis. 2014 May;58(10):1496. Dosage error in article text. PMID: 22965026; PMCID: PMC7108032.
Shaikh N, Swaminathan N, Hooper EG. Accuracy and precision of the signs and symptoms of streptococcal pharyngitis in children: a systematic review. J Pediatr. 2012 Mar;160(3):487-493.e3. doi: 10.1016/j.jpeds.2011.09.011. Epub 2011 Nov 1. PMID: 22048053.
Woods WA, Carter CT, Schlager TA. Detection of group A streptococci in children under 3 years of age with pharyngitis. Pediatr Emerg Care. 1999 Oct;15(5):338-40. doi: 10.1097/00006565-199910000-00011. PMID: 10532665.
Webb KH, Needham CA, Kurtz SR. Use of a high-sensitivity rapid strep test without culture confirmation of negative results: 2 years' experience. J Fam Pract. 2000 Jan;49(1):34-8. Erratum in: J Fam Prac 2000 Apr;49(4):378. PMID: 10678338.
Spinks A, Glasziou PP, Del Mar CB. Antibiotics for sore throat. Cochrane Database Syst Rev. 2013 Nov 5;2013(11):CD000023. doi: 10.1002/14651858.CD000023.pub4. Update in: Cochrane Database Syst Rev. 2021 Dec 9;12:CD000023. PMID: 24190439; PMCID: PMC6457983.