- ACRONYMS AND DEFINITIONS
- AAOHNS - American Academy of Otolaryngology–Head and Neck Surgery
- IDSA - Infectious Diseases Society of America
- GAS - Group A Streptococcus
- IM - Intramuscular
- RCT - Randomized controlled trial
- ETIOLOGY
- Overview
- Pharyngitis (sore throat) is one of the most common reasons for outpatient clinic visits, accounting for an estimated 15 million doctor visits annually in the U.S. alone. The vast majority of throat infections in children and adults are caused by viruses, while the second most common cause, Group A streptococcus, accounts for 20 - 30% of infections in children and 5 - 15% in adults. The table below describes the different pathogens.
ETIOLOGY OF PHARYNGITIS |
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Viruses (70 - 95% of infections) |
Adenovirus
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Herpes simplex 1 virus (gingivostomatitis)
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Coxsackievirus (Hand, foot, and mouth disease)
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Rhinovirus and coronavirus
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Influenza and Parainfluenza
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Epstein-Barr virus and Cytomegalovirus (mononucleosis)
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Bacteria (5 - 30% of infections) |
Group A Streptococcus
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Group C Streptococcus
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Group G Streptococcus
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Neisseria gonorrhoeae
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Corynebacterium diphtheriae
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- SYMPTOMS - BACTERIAL VS VIRAL
- Overview
- Pharyngitis, whether bacterial or viral, is almost always a self-limited infection
- The main reason for determining the cause is so that antibiotics can be given for GAS in order to prevent post-infectious sequelae (e.g. rheumatic heart disease, glomerulonephritis)
- Symptoms can help distinguish between the two, but they are inexact, and all suspected cases of strep throat should be confirmed with diagnostic testing. Studies have shown that 50 - 70% of patients with all the clinical signs of strep throat (fever, absence of cough, cervical lymphadenopathy, tonsillar swelling and exudate) have negative strep cultures.
- Symptoms suggestive of bacterial and viral etiologies are presented below [1,2]
- Symptoms consistent with strep throat:
- Sudden onset of sore throat
- Age 5–15 years
- Fever
- Headache
- Nausea, vomiting, abdominal pain
- Tonsillopharyngeal inflammation
- Patchy tonsillopharyngeal exudates
- Palatal petechiae
- Anterior cervical adenitis (tender nodes)
- Winter and early spring presentation
- History of exposure to strep pharyngitis
- Scarlatiniform rash [2]
- Symptoms consistent with viral infection:
- Conjunctivitis
- Runny nose
- Cough
- Diarrhea
- Hoarseness
- Discrete ulcerative stomatitis
- Viral exanthema [2]
- DIAGNOSIS
- Whom to test
- Patients with pharyngitis and symptoms suggestive of strep throat should universally be tested for GAS
- The Infectious Diseases Society of America (IDSA) issued recommendations for strep throat testing in 2012
- IDSA recommendations for GAS testing
- In general, children < 3 years old should not be tested, unless there is a strong suspicion for strep throat (Ex. sibling with confirmed strep throat)
- Adults and children with symptoms consistent with a viral infection (see symptoms above) should not be tested
- Rapid strep test is the initial test of choice in most patients
- Children and adolescents with a negative rapid strep test should have a backup throat culture
- Adults with a negative rapid strep test should not have a backup throat culture
- Patients with a positive rapid strep test do not need a throat culture
- Asymptomatic household contacts should not be tested or treated empirically
Diagnostic tests for strep throat | ||
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Test | Accuracy | Other |
Rapid antigen testing |
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Direct DNA probe tests |
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PCR testing |
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Culture |
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- COMPLICATIONS
- Overview
- Strep throat is a self-limited infection that typically resolves on its own regardless of antibiotic therapy. The main reason for treating strep throat with antibiotics is to prevent the secondary complications discussed below.
Complications of group A strep (GAS) pharyngitis |
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Rheumatic fever
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Rheumatic heart disease
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Otitis media
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Peritonsillar abscess
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Post-streptococcal glomerulonephritis
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Guttate psoriasis
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IgA vasculitis (Henoch-Schönlein purpura)
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- TREATMENT (IDSA RECOMMENDATIONS)
- Group A Strep (pediatric)
- Non-penicillin allergic
- Penicillin (Pen VK®) 250 mg twice daily or 3 times daily for 10 days ($)
- Amoxicillin 50 mg/kg once daily (max 1000 mg) OR 25 mg/kg (max 500 mg) twice daily for 10 days ($)
- Penicillin G benzathine (Bicillin L-A®)
- < 27 kg: 600,000 units IM ($$-$$$)
- ≥ 27 kg: 1,200,000 units IM ($$-$$$)
- Penicillin allergic
- Cephalexin (Keflex®)✝ 20 mg/kg/dose twice daily (max 500 mg/dose) for 10 days ($)
- Cefadroxil (Duricef®)✝ 30 mg/kg once daily (max 1000 mg) for 10 days ($)
- Clindamycin (Cleocin®) 7 mg/kg/dose 3 times daily (max 300 mg/dose) for 10 days ($-$$$)
- Azithromycin (Zithromax®) 12 mg/kg once daily (max 500 mg) for 5 days ($)
- Clarithromycin (Biaxin®) 7.5 mg/kg/dose twice daily (max 250 mg/dose) for 10 days ($-$$)
- Group A Strep (adults)
- Non-penicillin allergic
- Penicillin (Pen VK®) 250 mg 4 times daily OR 500 mg twice daily for 10 days ($)
- Amoxicillin 1000 mg once daily OR 500 mg twice a day for 10 days ($)
- Penicillin G benzathine (Bicillin L-A®) 1,200,000 units IM ($$-$$$)
- Penicillin allergic
- Cephalexin (Keflex®)✝ 500 mg twice a day for 10 days ($)
- Cefadroxil (Duricef®)✝ 1000 mg once daily for 10 days ($)
- Clindamycin (Cleocin®) 300 mg three times a day for 10 days ($-$$$)
- Azithromycin (Zithromax®) 500 mg once daily for 5 days ($)
- Clarithromycin (Biaxin®) 250 mg twice a day for 10 days ($-$$)
- Symptomatic treatment
- The IDSA recommends NSAIDs and acetaminophen for fever and pain symptoms
- Corticosteroids are sometimes used for severe symptoms. See studies below for more.
- STREP CARRIERS
- Overview
- Some people are chronic pharyngeal carriers of GAS. Carriers have GAS present in the pharynx with no symptoms of acute pharyngitis.
- Up to 20% of asymptomatic school children in temperate climates have been shown to be carriers of GAS in the winter and spring months
- GAS carriers are unlikely to spread the infection and do not appear to develop GAS complications
- Identifying carriers can be difficult. Patients who present with frequent pharyngitis that always tests positive for GAS should raise suspicion. These patients may be carriers who are experiencing the more common viral infections. Testing these patients for GAS when they are asymptomatic may help determine if they are carriers.
- Treating carriers to eradicate GAS is generally not recommended. If a decision is made to treat, one of the regimens below is recommended by the IDSA. [1,2]
- Treatment Regimens for Chronic GAS Carriers (one of the following):
- Clindamycin 20 - 30 mg/kg/day given in 3 doses (max 300 mg/dose) for 10 days
- Penicillin + rifampin
- Pen VK 50 mg/kg/day given in 4 doses (max 2000 mg/day) for 10 days
- Rifampin 20 mg/kg/day given once daily (max 600 mg/day) during the last 4 days of treatment
- Augmentin 40 mg amoxicillin/kg/day given in 3 doses (max 2000 mg amoxicillin/day) for 10 days
- Benzathine penicillin G + rifampin
- Benzathine penicillin G
- < 27 kg - 600,000 U IM
- ≥ 27 kg - 1,200,000 U IM
- Rifampin 20 mg/kg/day given in two divided doses (max 600 mg/day) for 4 days [2]
- RHEUMATIC FEVER PREVENTION
- Overview
- Patients with rheumatic fever should receive antibiotic prophylaxis to prevent recurrence because subsequent episodes can worsen existing rheumatic heart disease. Furthermore, group A strep infections may be asymptomatic, and recurrence can happen even when acute infections are treated. Recommendations on antibiotic choice and duration of prophylaxis from the American Heart Association are presented below. [8]
ANTIBIOTIC CHOICE | |
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Antibiotic | Regimen |
Penicillin G benzathine |
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Penicillin (Pen VK®) |
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Sulfadiazine |
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Macrolide antibiotics |
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DURATION OF PROPHYLAXIS | |
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Type of disease | Duration after last attack✝ |
Rheumatic fever with carditis and residual heart disease (clinical or echocardiographic) |
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Rheumatic fever with carditis but no residual heart disease |
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Rheumatic fever without carditis |
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✝ Lifelong prophylaxis may be recommended if the patient is at high risk of group A streptococcus exposure. Secondary rheumatic heart disease prophylaxis is required even after valve replacement. |
- TONSILLECTOMY RECOMMENDATIONS
AAOHNS 2019 recommendations for tonsillectomy |
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Throat infection criteria
Tonsillectomy may be considered in the following patients:
Factors that may favor tonsillectomy in patients who do not meet the above criteria:
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- STUDIES
- STUDY
- Design: Randomized, placebo-controlled trial (N=565 | length=1 month) in patients with acute sore throat not requiring immediate antibiotic therapy
- Treatment: Dexamethasone 10 mg one time vs Placebo
- Primary outcome: Proportion of participants experiencing complete resolution of symptoms at 24 hours
- Results:
- Primary outcome (24 hours): Dexamethasone - 22.6%, Placebo - 17.7% (p=0.14)
- Primary outcome (48 hours): Dexamethasone - 35.4%, Placebo - 27.1% (p=0.03)
- Findings: Among adults presenting to primary care with acute sore throat, a single dose of oral dexamethasone compared with placebo did not increase the proportion of patients with resolution of symptoms at 24 hours. However, there was a significant difference at 48 hours.
- STUDY
- Design: Systematic review and meta-analysis (8 RCTs encompassing 743 patients)
- Treatment: Corticosteroids vs Placebo
- Outcome measures: Percentage of patients with complete resolution at 24 and 48 hours, mean time to onset of pain relief, mean time to complete resolution of symptoms, days missed from work or school, recurrence, and adverse events
- Findings: Corticosteroids provide symptomatic relief of pain in sore throat, in addition to antibiotic therapy, mainly in participants with severe or exudative sore throat.
- BIBLIOGRAPHY
- 1 - PMID 21323542 - Streptococcal Pharyngitis, NEJM (2011)
- 2 - PMID 23091044 - Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America, (2012)
- 3 - PMID 19661138 - BMJ MA
- 4 - PMID 28285457 - Group A Streptococcus, Acute Rheumatic Fever and Rheumatic Heart Disease: Epidemiology and Clinical Considerations, Curr Treat Options Cardio Med (2017)
- 5 - PMID 23302723 - Bacterial infection–related glomerulonephritis in adults, Kidney International (2013)
- 6 - PMID 18246890 - Peritonsillar Abscess, American Family Physician (2008)
- 7 - PMID 30921525 - Clinical Practice Guideline: Tonsillectomy in Children (Update)-Executive Summary, Otolaryngol Head Neck Surg (2019)
- 8 - PMID 33332150 - 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines, Circulation (2020)
- 9 - PMID 19246689 - Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics, Circulation (2009)