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Acute tonsillitis and pharyngitis

Last updated: April 16, 2021

Summarytoggle arrow icon

Acute tonsillitis is an inflammation of the tonsils that frequently occurs in combination with an inflammation of the pharynx (tonsillopharyngitis). The terms tonsillitis and pharyngitis are often used interchangeably, but they refer to distinct sites of inflammation. Acute tonsillitis and pharyngitis are particularly common in children and young adults and are primarily caused by viruses or group A streptococci (GAS). They are characterized by the sudden onset of fever, sore throat, and painful swallowing. Patients may also have tender, swollen cervical lymph nodes and tonsillar exudates. The disease is normally self-limited. However, if GAS infection is confirmed via rapid antigen detection test and/or throat culture, treatment with antibiotics (most often penicillin) should be initiated to prevent rheumatic fever. Tonsillectomy is a treatment option for recurrent and chronic tonsillitis, especially in patients with tonsillar hypertrophy that causes obstructive sleep-disordered breathing. Peritonsillar abscess and parapharyngeal abscess are serious suppurative complications of acute bacterial tonsillitis and require immediate treatment.

Epidemiological data refers to the US, unless otherwise specified.

Trismus and change in voice quality indicate the formation of potentially life-threatening peritonsillar abscess!

Approach [2]

The diagnosis of acute tonsillitis or acute pharyngitis is primarily clinical.

Infectious mononucleosis (IM) can manifest with clinical features similar to acute bacterial tonsillopharyngitis. Consider a heterophile antibody test if clinical suspicion for IM is high.

The diagnostic workup of suspected acute bacterial tonsillopharyngitis is described below.

Clinical scoring systems

Modified Centor score [8][9]
Criteria Points
Age 3–14 years +1
15–44 years 0
> 44 years -1
Exudate or swelling on tonsils Yes +1
No 0
Tender or swollen anterior cervical lymph nodes Yes +1
No 0
Temperature > 100.4°F (38°C) Yes +1
No 0
Cough Absent +1
Present 0

Interpretation

  • Score ≤ 1: no further diagnostic testing needed
  • Score ≥ 2: Consider rapid antigen detection testing (RADT) and/or throat culture.
  • Score ≥ 4: Consider empiric antibiotic therapy (controversial) [2][10]

Think of M-CENTOR to remember the Modified Centor score criteria: M = Must be older than 3 years, C = Cough absent, E = Exudate on the tonsils, N = Node enlargement, T = Temperature elevation, OR = young OR old.

Empiric antibiotic therapy for patients with a modified Centor score ≥ 4 is not routinely recommended. [2]

Rapid antigen detection test (RADT) [2]

Testing for GAS infection is not recommended in patients with clinical features that strongly suggest acute viral tonsillopharyngitis. [2]

Throat culture

  • Indications
  • Findings
    • Causative bacteria and their antibiotic susceptibility (see “Etiology” for details)
    • Time to result: 24–48 hours

Additional laboratory tests

Not routinely indicated; can be obtained as supportive diagnostic evidence

An elevated antistreptolysin O (ASO) titer indicates a previous GAS infection. ASO titer assay is not indicated in an acute setting but rather in the workup of nonsuppurative complications of GAS tonsillopharyngitis (e.g., acute rheumatic fever, poststreptococcal glomerulonephritis). [2]

Imaging [11]

  • Not routinely indicated
  • Consider CT of head and neck if there is clinical suspicion of suppurative complications
Differential diagnoses of acute tonsillopharyngitis
Disease Etiology Clinical features
Aphthous stomatitis
  • Unknown
Herpangina
Herpetic pharyngotonsillitis/herpetic gingivostomatitis
Vincent angina
Ludwig angina
Oral thrush (fungal tonsillitis)
Pharyngeal syphilis
Tonsillitis in infectious mononucleosis
Tonsillitis in diphtheria (diphtheritic croup)
Agranulocytic angina

The differential diagnoses listed here are not exhaustive.

Approach [2]

General measures [2]

Avoid aspirin in children due to the risk of Reye syndrome.

Antibiotic therapy [2]

  • Indication: patients with laboratory confirmation of GAS infection [2][10]
  • Important consideration: The antibiotic regimens described here are valid for children ≥ 2 years of age and for adults.
Recommended antibiotic regimens for acute GAS pharyngitis [2]
Drug Duration
No penicillin allergy

Penicillin V : treatment of choice

10 days
Amoxicillin 10 days
Benzathine penicillin G : Single-dose
Penicillin allergy Cephalexin 10 days
Cefadroxil 10 days
History of anaphylaxis to penicillin: clindamycin or macrolides Clindamycin 10 days
Azithromycin 5 days
Clarithromycin 10 days

Mistakenly treating an EBV infection (infectious mononucleosis) with amoxicillin can lead to a maculopapular rash.

Tonsillectomy [1][2]

Indications [1][2][18]

  • Extreme hypertrophy of the tonsils (“kissing tonsils”) causing obstructive sleep-disordered breathing. [19]
  • Documented recurrent throat infections [20]
    • In patients who fulfill all of the following criteria: [1][2][18]
      1. Frequency of throat infections
        • ≥ 7 episodes in the past year
        • OR ≥ 5 episodes/year in the past 2 years
        • OR ≥ 3 episodes/year in the past 3 years
      2. Each episode has ≥ 1 of the following features:
      3. Each episode has been documented in a medical record.
    • If the above criteria are not met, consider tonsillectomy in patients with any of the following:
  • Suspected tonsillar neoplasm
  • Chronic tonsillitis

Procedure [1][21][22]

  • Total tonsillectomy
    • Tonsils are removed with their surrounding capsule.
    • Dissection is lateral to the tonsil in the plane between the tonsillar capsule and pharyngeal muscles.
  • Subtotal tonsillectomy
    • Subtotal removal of tonsillar tissue, leaving a margin of tissue on the tonsillar capsule
    • Dissection is from medial to lateral in a stepwise approach to preserve the capsule.

Do not use acetylsalicylic acid for postoperative pain relief after tonsillectomy because of the increased risk of bleeding. Recommended analgesics after tonsillectomy are ibuprofen and acetaminophen. [1][23]

Complications [1]

  • Intraoperative: injury to adjacent structures e.g., the carotid artery
  • Postoperative: bleeding , referred otalgia, nasopharyngeal stenosis

Streptococcus "ph"yogenes is the most common cause of bacterial pharyngitis, which can result in rheumatic "phever" and poststreptococcal glomerulonephritis.

References: [3][24]

We list the most important complications. The selection is not exhaustive.

  1. Mitchell et al. Clinical Practice Guideline: Tonsillectomy in Children (Update). Otolaryngology–Head and Neck Surgery. 2019; 160 (1): p.S1-S42. doi: 10.1177/0194599818801757 . | Open in Read by QxMD
  2. Shulman et al. Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis: 2012 Update by the Infectious Diseases Society of America. Clinical Infectious Diseases. 2012; 55 (10): p.e86–e102. doi: 10.1093/cid/cis629 . | Open in Read by QxMD
  3. Le T, Bhushan V, Bagga H. First Aid for the USMLE Step 2 CK. McGraw-Hill ; 2009 : p. 221-222
  4. Gibber MJ. Tonsillectomy in adults. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/tonsillectomy-in-adults?source=search_result&search=tonsillectomy&selectedTitle=2~57.Last updated: June 8, 2016. Accessed: November 6, 2016.
  5. Shapiro DJ, Lindgren CE, Neuman MI, Fine AM. Viral Features and Testing for Streptococcal Pharyngitis. Pediatrics. 2017; 139 (5): p.e20163403. doi: 10.1542/peds.2016-3403 . | Open in Read by QxMD
  6. Group A Strepcococcal (GAS) Disease - Pharyngitis (Strep Throat). https://www.cdc.gov/groupastrep/diseases-hcp/strep-throat.html. Updated: November 1, 2018. Accessed: August 24, 2020.
  7. Incidence of rash after amoxicillin treatment in children with infectious mononucleosis. https://www.ncbi.nlm.nih.gov/pubmed/23589810. Updated: May 1, 2013. Accessed: March 17, 2017.
  8. Heidi Lee, Scott Keller. Are the Centor criteria accurate in diagnosing streptococcal pharyngitis?. Evidence-Based Practice. 2018; 21 (9): p.39-40. doi: 10.1097/ebp.0000000000000032 . | Open in Read by QxMD
  9. 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). doi: 10.1001/archinternmed.2012.950 . | Open in Read by QxMD
  10. McIsaac WJ et al. Empirical Validation of Guidelines for the Management of Pharyngitis in Children and Adults. JAMA. 2004; 291 (13): p.1587. doi: 10.1001/jama.291.13.1587 . | Open in Read by QxMD
  11. Kalra MG, Higgins KE, Perez ED. Common questions about streptococcal pharyngitis. Am Fam Physician. 2016; 94 (1): p.24-31.
  12. Weber R. Pharyngitis. Prim Care. 2014; 41 (1): p.91-98. doi: 10.1016/j.pop.2013.10.010 . | Open in Read by QxMD
  13. Oliver J, Malliya Wadu E, Pierse N, Moreland NJ, Williamson DA, Baker MG. Group A Streptococcus pharyngitis and pharyngeal carriage: A meta-analysis. PLoS Negl Trop Dis. 2018; 12 (3): p.e0006335. doi: 10.1371/journal.pntd.0006335 . | Open in Read by QxMD
  14. Factor SH, Levine OS, Schwartz B, et al. Invasive Group A Streptococcal Disease: Risk Factors for Adults. Emerg Infect Dis. 2003; 9 (8): p.970-977. doi: 10.3201/eid0908.020745 . | Open in Read by QxMD
  15. Chow AW. Submandibular space infections (Ludwig's angina). In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/submandibular-space-infections-ludwigs-angina?source=search_result&search=ludwig%20angina&selectedTitle=1~9.Last updated: July 31, 2015. Accessed: November 6, 2016.
  16. Evidence-Based Diagnosis and Management of ENT Emergencies. https://www.medscape.com/viewarticle/551650_4. Updated: February 15, 2007. Accessed: May 6, 2019.
  17. Hicks CB, Clement M. Syphilis: Epidemiology, pathophysiology, and clinical manifestations in HIV-uninfected patients. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/syphilis-epidemiology-pathophysiology-and-clinical-manifestations-in-hiv-uninfected-patients?source=see_link§ionName=CLINICAL%20MANIFESTATIONS&anchor=H8#H8.Last updated: August 1, 2016. Accessed: November 6, 2016.
  18. Carapetis JR, Beaton A, Cunningham MW, et al. Acute rheumatic fever and rheumatic heart disease. Nat Rev Dis Primers. 2016; 2 (1). doi: 10.1038/nrdp.2015.84 . | Open in Read by QxMD
  19. Hoddeson EK, Gourin CG. Adult tonsillectomy: Current indications and outcomes. Otolaryngology–Head and Neck Surgery. 2009; 140 (1): p.19-22. doi: 10.1016/j.otohns.2008.09.023 . | Open in Read by QxMD
  20. Gozal D, Tan H-L, Kheirandish-Gozal L. Obstructive sleep apnea in children: a critical update. Nat Sci Sleep. 2013 : p.109. doi: 10.2147/nss.s51907 . | Open in Read by QxMD
  21. Burton MJ, Glasziou PP, Chong LY, Venekamp RP. Tonsillectomy or adenotonsillectomy versus non-surgical treatment for chronic/recurrent acute tonsillitis. Cochrane Database Syst Rev. 2014 . doi: 10.1002/14651858.cd001802.pub3 . | Open in Read by QxMD
  22. Messner AH. Tonsillectomy. Oper Tech Otolayngol Head Neck Surg. 2005; 16 (4): p.224-228. doi: 10.1016/j.otot.2005.09.005 . | Open in Read by QxMD
  23. Sathe N, Chinnadurai S, McPheeters M, Francis DO. Comparative Effectiveness of Partial versus Total Tonsillectomy in Children: A Systematic Review. Otolaryngol Head Neck Surg. 2017; 156 (3): p.456-463. doi: 10.1177/0194599816683916 . | Open in Read by QxMD
  24. Krishna S, Hughes LF, Lin SY. Postoperative Hemorrhage With Nonsteroidal Anti-inflammatory Drug Use After Tonsillectomy. Arch Otolaryngol Head Neck Surg. 2003; 129 (10): p.1086. doi: 10.1001/archotol.129.10.1086 . | Open in Read by QxMD
  25. Coelho MotaVera et al.. CHAPTER 54A - Rheumatic Fever. Churchille Livingstone : p. 1091-1113
  26. Pichichero ME. Complications of streptococcal tonsillopharyngitis. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/complications-of-streptococcal-tonsillopharyngitis.Last updated: February 4, 2016. Accessed: November 6, 2016.
  27. Little P, Hobbs FR, Moore M, et al. PRImary care Streptococcal Management (PRISM) study: in vitro study, diagnostic cohorts and a pragmatic adaptive randomised controlled trial with nested qualitative study and cost-effectiveness study. Health Technol Assess. 2014; 18 (6): p.1-102. doi: 10.3310/hta18060 . | Open in Read by QxMD
  28. Harris AM, Hicks LA, Qaseem A. Appropriate Antibiotic Use for Acute Respiratory Tract Infection in Adults: Advice for High-Value Care From the American College of Physicians and the Centers for Disease Control and Prevention. Ann Intern Med. 2016; 164 (6): p.425-34. doi: 10.7326/m15-1840 . | Open in Read by QxMD
  29. Paradise JL, Bluestone CD, Bachman RZ, et al. Efficacy of Tonsillectomy for Recurrent Throat Infection in Severely Affected Children. N Engl J Med. 1984; 310 (11): p.674-683. doi: 10.1056/nejm198403153101102 . | Open in Read by QxMD
  30. Goldstein NA, Stewart MG, Witsell DL, et al. Quality of life after tonsillectomy in children with recurrent tonsillitis. Otolaryngol Head Neck Surg. 2008; 138 (1_suppl): p.S9-S16. doi: 10.1016/j.otohns.2006.12.029 . | Open in Read by QxMD