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Streptococcal pharyngitis

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Streptococcal pharyngitis
Other names: Streptococcal tonsillitis, streptococcal sore throat, strep
A set of large tonsils in the back of the throat covered in white exudate
A culture positive case of streptococcal pharyngitis with typical tonsillar exudate in a 16-year-old.
SpecialtyInfectious disease
SymptomsFever, sore throat, large lymph nodes[1]
Usual onset1–3 days after exposure[2][3]
Duration7–10 days[2][3]
CausesGroup A streptococcus[1]
Risk factorsSharing drinks or eating utensils[4]
Diagnostic methodThroat culture, strep test[1]
Differential diagnosisEpiglottitis, infectious mononucleosis, Ludwig's angina, peritonsillar abscess, retropharyngeal abscess, viral pharyngitis[5]
PreventionHandwashing,[1] covering coughs[4]
TreatmentParacetamol (acetaminophen), NSAIDs, antibiotics[1][6]
Frequency5 to 40% of sore throats[7][8]

Streptococcal pharyngitis, also known as strep throat, is an infection of the back of the throat including the tonsils caused by group A streptococcus (GAS).[1] Common symptoms include fever, sore throat, red tonsils, and enlarged lymph nodes in the neck.[1] A headache, and nausea or vomiting may also occur.[1] Some develop a sandpaper-like rash which is known as scarlet fever.[2] Symptoms typically begin one to three days after exposure and last seven to ten days.[2][3]

Strep throat is spread by respiratory droplets from an infected person.[1] It may be spread directly or by touching something that has droplets on it and then touching the mouth, nose, or eyes.[1] Some people may carry the bacteria without symptoms.[1] It may also be spread by skin infected with group A strep.[1] Diagnosis is based on a rapid strep test or throat culture in those who have symptoms.[9][10]

Prevention is by washing hands and not sharing eating utensils.[1] There is no vaccine for the disease.[1] Treatment with antibiotics is only recommended in those with a confirmed diagnosis.[9] Those infected should stay away from other people for at least 24 hours after starting treatment.[1] Pain can be treated with paracetamol (acetaminophen) and nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen.[6]

Strep throat is a common bacterial infection in children with an estimated 288 million cases occuring in children age five to 14 years a year.[11] It is the cause of 15–40% of sore throats among children[7][12] and 5–15% among adults.[8] Cases are more common in late winter and early spring.[12] Potential complications include rheumatic fever and peritonsillar abscess.[1]

Signs and symptoms

The typical signs and symptoms of strep throat are a sore throat, fever, pus on the tonsils), and large neck glands.[1] It tends to make swallowing painful.[1]

Other symptoms include: headache, nausea and vomiting, abdominal pain,[1] [13] muscle pain.[14] or palatal petechiae; an uncommon but highly specific finding.[12] When accompanied by a scarlet rash it as referred to as scarlet fever.[1]

Symptoms typically begin one to three days after exposure and last seven to ten days.[3][12]

Strep throat is unlikely when any of the symptoms of red eyes, hoarseness, runny nose, or mouth ulcers are present. It is also unlikely when there is no fever.[8]


Strep throat is caused by group A β-hemolytic Streptococcus (GAS or S. pyogenes).[15] Other bacteria such as non–group A β-hemolytic streptococci and fusobacterium may also cause pharyngitis.[12][14] It is spread by direct, close contact with an infected person; thus crowding, as may be found in the military and schools, increases the rate of transmission.[14][16] Dried bacteria in dust are not infectious, although moist bacteria on toothbrushes or similar items can persist for up to fifteen days.[14] Contaminated food can result in outbreaks, but this is rare.[14] Of children with no signs or symptoms, 12% carry GAS in their pharynx,[7] and, after treatment, approximately 15% of those remain positive, and are true "carriers".[17]


Modified Centor score
Points Probability of Strep Management
1 or fewer <10% No antibiotic or culture needed
2 11–17% Antibiotic based on culture or RADT
3 28–35%
4 or 5 52% Empiric antibiotics

A number of scoring systems exist to help with diagnosis; however, their use is controversial due to insufficient accuracy.[18] The modified Centor criteria are a set of five criteria; the total score indicates the probability of a streptococcal infection.[12]

One point is given for each of the criteria:[12]

  • Absence of a cough
  • Swollen and tender cervical lymph nodes
  • Temperature >38.0 °C (100.4 °F)
  • Tonsillar exudate or swelling
  • Age less than 15 (a point is subtracted if age >44)

A score of one may indicate no treatment or culture is needed or it may indicate the need to perform further testing if other high risk factors exist, such as a family member having the disease.[12]

The Infectious Disease Society of America recommends against empirical treatment and considers antibiotics only appropriate when given after a positive test.[8] Testing is not needed in children under three as both group A strep and rheumatic fever are rare, unless the child has a sibling with the disease.[8][19] Also, those with clear viral symptoms, such as cough, runny nose, hoarseness, and red eyes, do not need further testing.[19]

Laboratory testing

A throat culture is the gold standard for the diagnosis of streptococcal pharyngitis, with a sensitivity of 90–95%.[12][20] A rapid strep test, also called a rapid antigen detection testing (RADT) or nucleic acid detection test, may also be used.[10] While the rapid strep test is quicker, it has a lower sensitivity (85 to 92%), though equal specificity (98%) as a throat culture.[12][10]

A positive throat culture or RADT in association with symptoms establishes a positive diagnosis in those in which the diagnosis is in doubt.[21] In areas of the world where rheumatic fever is uncommon, a negative rapid strep test is sufficient to rule out the disease in adults; though the CDC still recommends culturing in children.[22][23][8]

Asymptomatic individuals should not be routinely tested with a throat culture or RADT because some of the population persistently "carries" the streptococcal bacteria in their throat without any harmful results.[21]

Differential diagnosis

As the symptoms of streptococcal pharyngitis overlap with other conditions, it can be difficult to make the diagnosis clinically.[12] Coughing, nasal discharge, diarrhea, and red, irritated eyes in addition to fever and sore throat are more indicative of a viral sore throat than of strep throat.[12] The presence of marked lymph node enlargement along with sore throat, fever, and tonsillar enlargement may also occur in infectious mononucleosis.[24] Other conditions that may present similarly include epiglottitis, Kawasaki disease, acute retroviral syndrome, Lemierre's syndrome, Ludwig's angina, peritonsillar abscess, and retropharyngeal abscess.[5]


Tonsillectomy may be a reasonable preventive measure in those with frequent throat infections (more than three a year).[25] However, the benefits are small and episodes typically lessen in time regardless of measures taken.[26][27][28] Recurrent episodes of pharyngitis which test positive for GAS may also represent a person who is a chronic carrier of GAS who is getting recurrent viral infections.[8] Treating people who have been exposed but who are without symptoms is not recommended.[8] Treating people who are carriers of GAS is not recommended as the risk of spread and complications is low.[8]


Untreated streptococcal pharyngitis usually resolves within a few days.[12] Treatment with antibiotics shortens the duration of the acute illness by about 16 hours.[12] The primary reason for treatment with antibiotics is to reduce the risk of complications such as rheumatic fever and retropharyngeal abscesses.[12] Antibiotics prevent acute rheumatic fever if given within 9 days of the onset of symptoms.[15]

Pain medication

Pain medication such as NSAIDs and paracetamol (acetaminophen) helps in the management of pain associated with strep throat.[29] Viscous lidocaine may also be useful.[30] While steroids may help with the pain,[15][31] they are not routinely recommended.[8] Aspirin may be used in adults but is not recommended in children due to the risk of Reye syndrome.[15]


The antibiotic of choice in the United States for streptococcal pharyngitis is penicillin V, due to safety, cost, and effectiveness.[12] Amoxicillin is preferred in Europe.[32] In India, where the risk of rheumatic fever is higher, intramuscular benzathine penicillin G is the first choice for treatment.[15] In areas with a low risk of rheumatic fever 5 days of penicillin V or amoxicillin is sufficient while in regions with were it is common, 10 days are used.[33][34]

Appropriate antibiotics decrease the average 3–5 day duration of symptoms by about one day, and also reduce contagiousness.[21] They are primarily prescribed to reduce rare complications such as rheumatic fever and peritonsillar abscess.[35] The arguments in favor of antibiotic treatment should be balanced by the consideration of possible side effects,[14] and it is reasonable to suggest that no antimicrobial treatment be given to healthy adults who have adverse reactions to medication or those at low risk of complications.[35][36] Antibiotics are prescribed for strep throat at a higher rate than would be expected from how common it is.[37]

Erythromycin and other macrolides or clindamycin are recommended for people with severe penicillin allergies.[12][8] First-generation cephalosporins may be used in those with less severe allergies[12] and some evidence supports cephalosporins as superior to penicillin.[38][39] These late-generation antibiotics show a similar effect when prescribed for 3-7 days in comparison to the standard 10-days of penicillin when used in areas of low rheumatic heart disease.[40] Streptococcal infections may also lead to acute glomerulonephritis; while the risk of this side effect has often been stated to not be reduced by the use of antibiotics, others have stated that antibiotics may decrease the risk.[15][41]


The symptoms of strep throat usually improve within three to five days, irrespective of treatment.[21] Treatment with antibiotics reduces the risk of complications and transmission; children may return to school 24 hours after antibiotics are administered.[12] The risk of complications in adults is low.[8] In children, acute rheumatic fever is rare in most of the developed world. It is, however, the leading cause of acquired heart disease in India, sub-Saharan Africa and some parts of Australia.[8]

Complications arising from streptococcal throat infections include:

The economic cost of the disease in the United States in children is approximately $350 million annually.[8]


Pharyngitis, the broader category into which Streptococcal pharyngitis falls, is diagnosed in 11 million people annually in the United States.[12] It is the cause of 15–40% of sore throats among children[7][12] and 5–15% in adults.[8] Cases usually occur in late winter and early spring.[12]


  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 "Is your sore throat strep?". Centers for Disease Control and Prevention. 2 November 2022. Archived from the original on 3 December 2022. Retrieved 5 December 2022.
  2. 2.0 2.1 2.2 2.3 Török, edited by David A. Warrell, Timothy M. Cox, John D. Firth; with guest ed. Estée (2012). Oxford textbook of medicine infection. Oxford: Oxford University Press. pp. 280–281. ISBN 9780191631733. Archived from the original on 2016-10-10.
  3. 3.0 3.1 3.2 3.3 Jr, [edited by] Allan H. Goroll, Albert G. Mulley (2009). Primary care medicine : office evaluation and management of the adult patient (6th ed.). Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. p. 1408. ISBN 9780781775137. Archived from the original on 2016-09-15.
  4. 4.0 4.1 "Strep throat - Symptoms and causes". Mayo Clinic. Archived from the original on 4 July 2021. Retrieved 24 January 2020.
  5. 5.0 5.1 Gottlieb, M; Long, B; Koyfman, A (May 2018). "Clinical Mimics: An Emergency Medicine-Focused Review of Streptococcal Pharyngitis Mimics". The Journal of Emergency Medicine. 54 (5): 619–629. doi:10.1016/j.jemermed.2018.01.031. PMID 29523424.
  6. 6.0 6.1 Weber, R (March 2014). "Pharyngitis". Primary Care. 41 (1): 91–8. doi:10.1016/j.pop.2013.10.010. PMC 7119355. PMID 24439883.
  7. 7.0 7.1 7.2 7.3 Shaikh N, Leonard E, Martin JM (September 2010). "Prevalence of streptococcal pharyngitis and streptococcal carriage in children: a meta-analysis". Pediatrics. 126 (3): e557–64. doi:10.1542/peds.2009-2648. PMID 20696723.
  8. 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 8.11 8.12 8.13 8.14 8.15 8.16 8.17 Shulman, ST; Bisno, AL; Clegg, HW; Gerber, MA; Kaplan, EL; Lee, G; Martin, JM; Van Beneden, C (Sep 9, 2012). "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. 55 (10): e86–102. doi:10.1093/cid/cis629. PMID 22965026.
  9. 9.0 9.1 Harris, AM; Hicks, LA; Qaseem, A (19 January 2016). "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". Annals of Internal Medicine. 164 (6): 425–34. doi:10.7326/M15-1840. PMID 26785402.
  10. 10.0 10.1 10.2 Ton, Joey (28 October 2019). "#246 Just wait a minute: Point-of-care testing for Group A Streptococcal pharyngitis". CFPCLearn. Archived from the original on 25 March 2023. Retrieved 15 June 2023.
  11. Miller, Kate M.; Carapetis, Jonathan R.; Beneden, Chris A. Van; Cadarette, Daniel; Daw, Jessica N.; Moore, Hannah C.; Bloom, David E.; Cannon, Jeffrey W. (1 June 2022). "The global burden of sore throat and group A Streptococcus pharyngitis: A systematic review and meta-analysis". eClinicalMedicine. 48. doi:10.1016/j.eclinm.2022.101458. ISSN 2589-5370. Archived from the original on 3 December 2022. Retrieved 5 December 2022.
  12. 12.00 12.01 12.02 12.03 12.04 12.05 12.06 12.07 12.08 12.09 12.10 12.11 12.12 12.13 12.14 12.15 12.16 12.17 12.18 12.19 12.20 12.21 12.22 Choby BA (March 2009). "Diagnosis and treatment of streptococcal pharyngitis". Am Fam Physician. 79 (5): 383–90. PMID 19275067. Archived from the original on 2015-02-08.
  13. 13.0 13.1 Brook I, Dohar JE (December 2006). "Management of group A beta-hemolytic streptococcal pharyngotonsillitis in children". J Fam Pract. 55 (12): S1–11, quiz S12. PMID 17137534.
  14. 14.0 14.1 14.2 14.3 14.4 14.5 Hayes CS, Williamson H (April 2001). "Management of Group A beta-hemolytic streptococcal pharyngitis". Am Fam Physician. 63 (8): 1557–64. PMID 11327431. Archived from the original on 2008-05-16.
  15. 15.0 15.1 15.2 15.3 15.4 15.5 Baltimore RS (February 2010). "Re-evaluation of antibiotic treatment of streptococcal pharyngitis". Curr. Opin. Pediatr. 22 (1): 77–82. doi:10.1097/MOP.0b013e32833502e7. PMID 19996970.
  16. Lindbaek M, Høiby EA, Lermark G, Steinsholt IM, Hjortdahl P (2004). "Predictors for spread of clinical group A streptococcal tonsillitis within the household". Scand J Prim Health Care. 22 (4): 239–43. doi:10.1080/02813430410006729. PMID 15765640.
  17. Rakel, edited by Robert E. Rakel, David P. (2011). Textbook of family medicine (8th ed.). Philadelphia, PA.: Elsevier Saunders. p. 331. ISBN 9781437711608. Archived from the original on 2017-09-08.
  18. Cohen, JF; Cohen, R; Levy, C; Thollot, F; Benani, M; Bidet, P; Chalumeau, M (6 January 2015). "Selective testing strategies for diagnosing group A streptococcal infection in children with pharyngitis: a systematic review and prospective multicentre external validation study". Canadian Medical Association Journal. 187 (1): 23–32. doi:10.1503/cmaj.140772. PMC 4284164. PMID 25487666.
  19. 19.0 19.1 "Pharyngitis (Strep Throat): Information For Clinicians | CDC". 13 July 2023. Archived from the original on 27 October 2020. Retrieved 21 February 2024.
  20. Smith, Ellen Reid; Kahan, Scott; Miller, Redonda G. (2008). In A Page Signs & Symptoms. In a Page Series. Hagerstown, Maryland: Lippincott Williams & Wilkins. p. 312. ISBN 978-0-7817-7043-9.
  21. 21.0 21.1 21.2 21.3 Bisno AL, Gerber MA, Gwaltney JM, Kaplan EL, Schwartz RH (July 2002). "Practice guidelines for the diagnosis and management of group A streptococcal pharyngitis. Infectious Diseases Society of America" (PDF). Clin. Infect. Dis. 35 (2): 113–25. doi:10.1086/340949. PMID 12087516. Archived from the original on 2020-11-01. Retrieved 2018-04-20.
  22. Lean, WL; Arnup, S; Danchin, M; Steer, AC (October 2014). "Rapid diagnostic tests for group A streptococcal pharyngitis: a meta-analysis". Pediatrics. 134 (4): 771–81. doi:10.1542/peds.2014-1094. PMID 25201792.
  23. "Is your sore throat strep?". Centers for Disease Control and Prevention. 19 January 2024. Archived from the original on 3 December 2022. Retrieved 21 February 2024.
  24. Ebell MH (2004). "Epstein-Barr virus infectious mononucleosis". Am Fam Physician. 70 (7): 1279–87. PMID 15508538. Archived from the original on 2008-07-24.
  25. Johnson BC, Alvi A (March 2003). "Cost-effective workup for tonsillitis. Testing, treatment, and potential complications". Postgrad Med. 113 (3): 115–8, 121. doi:10.3810/pgm.2003.03.1391. PMID 12647478.
  26. van Staaij BK, van den Akker EH, van der Heijden GJ, Schilder AG, Hoes AW (January 2005). "Adenotonsillectomy for upper respiratory infections: evidence based?". Archives of Disease in Childhood. 90 (1): 19–25. doi:10.1136/adc.2003.047530. PMC 1720065. PMID 15613505.
  27. Burton, MJ; Glasziou, PP; Chong, LY; Venekamp, RP (19 November 2014). "Tonsillectomy or adenotonsillectomy versus non-surgical treatment for chronic/recurrent acute tonsillitis" (PDF). The Cochrane Database of Systematic Reviews (11): CD001802. doi:10.1002/14651858.CD001802.pub3. PMID 25407135. Archived (PDF) from the original on 15 May 2021. Retrieved 1 December 2019.
  28. Morad, Anna; Sathe, Nila A.; Francis, David O.; McPheeters, Melissa L.; Chinnadurai, Sivakumar (17 January 2017). "Tonsillectomy Versus Watchful Waiting for Recurrent Throat Infection: A Systematic Review". Pediatrics. 139 (2): e20163490. doi:10.1542/peds.2016-3490. ISSN 0031-4005. PMC 5260157. PMID 28096515. Archived from the original on 13 August 2017.
  29. Thomas M, Del Mar C, Glasziou P (October 2000). "How effective are treatments other than antibiotics for acute sore throat?". Br J Gen Pract. 50 (459): 817–20. PMC 1313826. PMID 11127175.
  30. "Generic Name: Lidocaine Viscous (Xylocaine Viscous) side effects, medical uses, and drug interactions". Archived from the original on 2010-04-08. Retrieved 2010-05-07.
  31. Wing, A; Villa-Roel, C; Yeh, B; Eskin, B; Buckingham, J; Rowe, BH (May 2010). "Effectiveness of corticosteroid treatment in acute pharyngitis: a systematic review of the literature". Academic Emergency Medicine. 17 (5): 476–83. doi:10.1111/j.1553-2712.2010.00723.x. PMID 20536799. Archived from the original on 2021-06-04. Retrieved 2019-12-01.
  32. Bonsignori F, Chiappini E, De Martino M (2010). "The infections of the upper respiratory tract in children". Int J Immunopathol Pharmacol. 23 (1 Suppl): 16–9. PMID 20152073.
  33. Web Annex. Infographics. In: The WHO AWaRe (Access, Watch, Reserve) antibiotic book (PDF). World Health Organization. 2022. p. 48. Archived (PDF) from the original on 28 January 2023. Retrieved 29 March 2023.
  34. Altamimi, S; Khalil, A; Khalaiwi, KA; Milner, RA; Pusic, MV; Al Othman, MA (15 August 2012). "Short-term late-generation antibiotics versus longer term penicillin for acute streptococcal pharyngitis in children". The Cochrane database of systematic reviews (8): CD004872. doi:10.1002/14651858.CD004872.pub3. PMID 22895944.
  35. 35.0 35.1 Snow V, Mottur-Pilson C, Cooper RJ, Hoffman JR (March 2001). "Principles of appropriate antibiotic use for acute pharyngitis in adults". Ann Intern Med. 134 (6): 506–8. doi:10.7326/0003-4819-134-6-200103200-00018. PMID 11255529.[needs update?]
  36. Hildreth, AF; Takhar, S; Clark, MA; Hatten, B (September 2015). "Evidence-Based Evaluation And Management Of Patients With Pharyngitis In The Emergency Department". Emergency Medicine Practice. 17 (9): 1–16, quiz 16–7. PMID 26276908.
  37. Linder JA, Bates DW, Lee GM, Finkelstein JA (November 2005). "Antibiotic treatment of children with sore throat". J Am Med Assoc. 294 (18): 2315–22. doi:10.1001/jama.294.18.2315. PMID 16278359.
  38. Pichichero, M; Casey, J (June 2006). "Comparison of European and U.S. results for cephalosporin versus penicillin treatment of group A streptococcal tonsillopharyngitis". European Journal of Clinical Microbiology & Infectious Diseases. 25 (6): 354–64. doi:10.1007/s10096-006-0154-7. PMID 16767482.
  39. van Driel, ML; De Sutter, AI; Habraken, H; Thorning, S; Christiaens, T (11 September 2016). "Different antibiotic treatments for group A streptococcal pharyngitis". The Cochrane Database of Systematic Reviews. 9: CD004406. doi:10.1002/14651858.CD004406.pub4. PMC 6457741. PMID 27614728.
  40. Altamimi, Saleh; Khalil, Adli; Khalaiwi, Khalid A; Milner, Ruth A; Pusic, Martin V; Al Othman, Mohammed A (15 August 2012). "Short-term late-generation antibiotics versus longer term penicillin for acute streptococcal pharyngitis in children". Cochrane Database of Systematic Reviews (8): CD004872. doi:10.1002/14651858.CD004872.pub3. PMID 22895944.
  41. Sainato, Rebecca J.; Weisse, Martin E. (January 2019). "Poststreptococcal Glomerulonephritis and Antibiotics: A Fresh Look at Old Data". Clinical Pediatrics. 58 (1): 10–12. doi:10.1177/0009922818793345.
  42. 42.0 42.1 "UpToDate Inc". Archived from the original on 2008-12-08.
  43. Stevens DL, Tanner MH, Winship J, et al. (July 1989). "Severe group A streptococcal infections associated with a toxic shock-like syndrome and scarlet fever toxin A". N. Engl. J. Med. 321 (1): 1–7. doi:10.1056/NEJM198907063210101. PMID 2659990.
  44. 44.0 44.1 Hahn RG, Knox LM, Forman TA (May 2005). "Evaluation of poststreptococcal illness". Am Fam Physician. 71 (10): 1949–54. PMID 15926411.

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