Pharyngitis

Author Credentials 

Sungjin A. Song, MD
Department of Otolaryngology
Massachusetts Eye and Ear Infirmary
Harvard Medical School
243 Charles Street
Boston, MA 02114
Phone 617-573-3958
Fax 617-573-3626
Sungjin_Song@meei.harvard.edu

Matthew R. Naunheim, MD, MBA
Department of Otolaryngology
Massachusetts Eye and Ear Infirmary
Harvard Medical School
243 Charles Street
Boston, MA 02114
Phone 617-573-4402
Fax 617-573-3626
Matthew_Naunheim@meei.harvard.edu

Module Summary

Pharyngitis is one of the most common conditions encountered in outpatient clinical practice. Most cases are self-limited and caused by respiratory viruses. It is important to recognize and treat bacterial pharyngitis to prevent potential complications.

Module Learning Objectives 
  1. Describe the signs and symptoms of pharyngitis.
  2. Formulate a differential diagnosis pharyngitis.
  3. Explain the different pathogenesis of pharyngitis.
  4. Identify the role of antibiotics in management of pharyngitis.
  5. Review the role of throat cultures in management of pharyngitis.
  6. Explain the indications for surgical intervention in patients with recurrent pharyngitis.
  7. Cite the potential complications of pharyngitis.   

 

Anatomy

Learning Objectives 
  1. Recognized that the pharynx is divided into three parts: the nasopharynx, oropharynx, and hypopharynx; “pharyngitis” generally refers to inflammation of the oropharynx and soft palate. 
  2. Recognize that pharyngeal inflammation can impact part or all of the pharynx and that the distribution of inflammation is not necessarily associated with the underlying etiology of the inflammation.
  3. Identify edema, erythema and hypervascularity as non-specific signs of pharyngeal inflammation.
  4. Describe the sensory nerve supply to the upper airway and sensation of sore throat through the pharyngeal plexus:
  • Glossopharyngeal nerve primarily
  • Maxillary branch of the trigeminal nerve - palatine tonsils

 

References 
  1. Bisno AL. Acute pharyngitis. N Engl J Med 2001 Jan 18;344(3):205-11.
  2. Bathala S, Eccles R. A review on the mechanism of sore throat in tonsillitis. J Laryngol Otol 2013 Mar;127(3):227-32.

 

Pathogenesis

Learning Objectives 

Infectious Pharyngitis:

  1. Recognize that acute pharyngitis is generally due to pharyngeal inflammation associated with a viral upper respiratory tract infection and resolves in less than two weeks but can result in fever, malaise, neck pain and swelling: 
  • Viral - most common cause of acute pharyngitis (rhinovirus, coronavirus, and adenovirus)
  • Infectious Mononucleosis (EBV) <1%
  • HIV <1%
  1. Formulate a differential diagnosis for the pathogenesis of bacterial pharyngitis and be familiar with the proposed mechanisms of pharyngeal irritation for each: 
  • Group A streptococcus - most common bacterial cause
  • Group C and G streptococcus
  • Neisseria gonorrhoeae
  • Diphtheria
  • Arcanobacterium haemolyticum
  • Fusobacterium necrophorum
  • Mycoplasmal
  • Chlamydial
  1. Other chronic infectious diseases e.g., candida, tuberculosis, syphilis, leprosy.
  2. Secondary to other pharyngeal process:
  • Peritonsillar or deep neck space abscess
  • Malignancy with superimposed infection

Non-infectious:

  • Allergic rhinitis
  • Laryngopharyngeal reflux
  • Smoking or second-hand smoke exposure
  • Caustic ingestion
  • Post-intubation
  • Systemic diseases may impact the pharynx directly or indirectly, e.g. thyroid disorders, granulomatosis with polyangiitis (GPA), sarcoidosis, Crohn’s disease 

 

References 
  1. Bisno AL. Acute pharyngitis. N Engl J Med 2001 Jan 18;344(3):205-11.
  2. Luzuriaga K, Sullivan JL. Infectious mononucleosis. N Engl J Med 2010 May 27;362(21):1993-2000.
  3. Tindall B, Barker S, Donovan B, Barnes T, Roberts J, Kronenberg C, Gold J, Penny R, Cooper D. Characterization of the acute clinical illness associated with human immunodeficiency virus infection. Arch Intern Med 1988 Apr;148(4):945-9
  4. Shulman ST, Bisno AL, Clegg HW, Gerber MA, Kaplan EL, Lee G, Martin JM, Van Beneden C. 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):1279-82.
  5. Renner B, Mueller CA, Shephard A. Environmental and non-infectious factors in the aetiology of pharyngitis (sore throat). Inflamm Res 2012 Oct;61(10):1041-52.

 

Basic Science

Learning Objectives 
  1. Describe the inflammatory mechanisms in the pharyngeal mucosa and epithelium that lead to pharyngitis: 
  • Transient receptor potential vanilloid 1 (TRPV1) are pain receptors in nerves that innervate the entire respiratory tract
  • IL-1, IL-6, TNF, and prostaglandins: fever
  • Prostaglandins (PGE2) and bradykinin: pain
  • Prostaglandins and nitric oxide: edema
  1. Discuss the theory regarding the protective nature of the pharyngeal microbiome, and the asymptomatic carrier rate of group A strep for different age groups:
  • Younger than 3 years old: 1.9-7.1%
  • 3-15 years old: 5-21.2%
  • Older adolescents and adults: 2.4-3.7% 

 

References 
  1. Ebell MH, Smith MA, Barry HC, Ives K, Carey M. The rational clinical examination. Does this patient have strep throat? Jama 2000 Dec 13;284(22):2912-8.
  2. Bathala S, Eccles R. A review on the mechanism of sore throat in tonsillitis. J Laryngol Otol 2013 Mar;127(3):227-32.

 

Incidence

Learning Objectives 
  1. State the incidence of acute pharyngitis and the relative prevalence of the various etiologies in the general population:  
  • Accounts for 1-2% of all outpatient visits
  • Approximately 5-15% of adult cases are caused by group A strep

 

References 
  1. Schappert SM, Rechtsteiner EA. Ambulatory medical care utilization estimates for 2006. Natl Health Stat Report 2008 Aug 6;(8)(8):1-29.
  2. Snow V, Mottur-Pilson C, Cooper RJ, Hoffman JR, American Academy of Family Physicians, American College of Physicians-American Society of Internal Medicine, Centers for Disease Control. Principles of appropriate antibiotic use for acute pharyngitis in adults. Ann Intern Med 2001 Mar 20;134(6):506-8.
  3. Bisno AL. Acute pharyngitis. N Engl J Med 2001 Jan 18;344(3):205-11.

 

Patient Evaluation

Learning Objectives 
  1. Recognize that history may offer clues as to etiology of pharyngitis:
  • Onset, duration, severity, and progression are all important factors
  1. Evaluate the full past medical history to find associated conditions leading to pharyngeal inflammation. 
  2. Describe the findings associated with pharyngitis and discuss the implications of the physical examination on the underlying etiology of the inflammation: 
  • Recognize that physical examination findings are generally non-specific and often cannot distinguish the underlying etiology of inflammation. 
  • Most useful findings for evaluating the likelihood of strep throat are presence of the Centor criteria: tonsillar exudate, tender cervical adenopathy, history of fever, and absence of cough.  
  1. Evaluate for serious or potentially life-threatening conditions:
  • Airway obstruction, epiglottitis, supraglottitis
  • Deep neck space infection, peritonsillar abscess

 

References 
  1. Ebell MH, Smith MA, Barry HC, Ives K, Carey M. The rational clinical examination. does this patient have strep throat? Jama 2000 Dec 13;284(22):2912-8.
  2. Bisno AL. Acute pharyngitis. N Engl J Med 2001 Jan 18;344(3):205-11.
  3. Centor RM, Witherspoon JM, Dalton HP, Brody CE, Link K. The diagnosis of strep throat in adults in the emergency room. Med Decis Making 1981;1(3):239-46.
  4. Renner B, Mueller CA, Shephard A. Environmental and non-infectious factors in the aetiology of pharyngitis (sore throat). Inflamm Res 2012 Oct;61(10):1041-52.

 

Imaging

Learning Objectives 
  1. Recognize that radiologic studies are not indicated or helpful in the evaluation of pharyngitis, unless a complication or other pathology is expected (e.g., peritonsillar abscess, deep neck space infection).

Pathology

Learning Objectives 
  1. Determine the role of rapid test for group A streptococcal antigen and throat culture in the diagnosis of bacterial pharyngitis:
  • Rapid antigen-detection test- 70-90% sensitivity
  • Negative rapid test in children requires confirmatory throat culture
  • Throat culture is the gold standard- 90% sensitivity
  1. Explain the inability of rapid test or conventional throat culture to differentiate acutely infected patients from asymptomatic carriers.
  2. Explain that patients with recurrent pharyngitis that tests positive for group A strep may actually be a group A strep carrier with repeated viral infections.

 

References 
  1. Bisno AL. Acute pharyngitis. N Engl J Med 2001 Jan 18;344(3):205-11.
  2. Shulman ST, Bisno AL, Clegg HW, Gerber MA, Kaplan EL, Lee G, Martin JM, Van Beneden C. 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):1279-82.

 

Treatment

Learning Objectives 
  1. Discuss treatments based on likely etiology of the underlying pharyngeal inflammation.
  2. Create a treatment algorithm and decision-making based on response to treatment and test results. 

 

References 
  1. Cooper RJ, Hoffman JR, Bartlett JG, Besser RE, Gonzales R, Hickner JM, Sande MA, American Academy of Family Physicians, American College of Physicians-American Society of Internal Medicine, Centers for Disease Control. Principles of appropriate antibiotic use for acute pharyngitis in adults: Background. Ann Intern Med 2001 Mar 20;134(6):509-17.
  2. Ebell MH, Smith MA, Barry HC, Ives K, Carey M. The rational clinical examination. does this patient have strep throat? Jama 2000 Dec 13;284(22):2912-8.

 

Medical Therapies

Learning Objectives 
  1. Discuss treatment for acute pharyngitis:
  • Analgesic therapy- aspirin, acetaminophen, NSAIDs
  • Throat lozenges and sprays
  • Viscous lidocaine
  • Supportive care: hydration, humidification, salt water gargles
  • Antibiotics if appropriate (see Pharmacology)
  1. Adjunctive therapy with corticosteroids is not recommended in routine cases.
  2. Manage allergic rhinitis as appropriate and consider allergy testing in patients for whom an allergic etiology is suspected. 
  3. Awareness that both viral and bacterial causes of pharyngitis can be transmitted to others. 

 

References 
  1. Harris AM, Hicks LA, Qaseem A, High Value Care Task Force of the American College of Physicians and for the Centers for Disease Control and Prevention. 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 Mar 15;164(6):425-34.
  2. Bisno AL. Acute pharyngitis. N Engl J Med 2001 Jan 18;344(3):205-11.

 

Pharmacology

Learning Objectives 
  1. Choose appropriate duration and therapy for the management of bacterial pharyngitis and for patients with an allergy to penicillin. 
  • Penicillin, amoxicillin- first line option
  • Cephalosporin
  • Clarithromycin
  • Azithromycin
  • Clindamycin
  1. Discuss response to therapy and inform patients of the need for antibiotic therapy to prevent suppurative complications. 
  2. Be familiar with the incidence of antibiotic resistance in cases of bacterial pharyngitis and proposed antibiotic choices based on that incidence. 
  • Group A strep does not have documented resistance against penicillin
  • Resistance to clindamycin is 1%
  1. Inform patient that overtreatment of sore throat leads to antibiotic resistant organisms.

 

References 
  1. Schwartz RH, Wientzen RL,Jr, Pedreira F, Feroli EJ, Mella GW, Guandolo VL. Penicillin V for group A streptococcal pharyngotonsillitis. A randomized trial of seven vs ten days' therapy. Jama 1981 Oct 16;246(16):1790-5.
  2. Bisno AL. Acute pharyngitis. N Engl J Med 2001 Jan 18;344(3):205-11.

 

Surgical Therapies

Learning Objectives 
  1. Discuss the role of surgery in cases of pharyngitis unresponsive to empiric antibiotic treatment or recurrent episodes of pharyngitis: 
  • Tonsillectomy solely to reduce frequency of group A streptococcal pharyngitis in adults is not recommended
  1. Explain the indications for tonsillectomy: 
  • Children with recurrent throat infections with a frequency of at least:
    • 7 episodes in the past year
    • 5 episodes per year for 2 years
    • 3 episodes per year for 3 years
  • Recurrent throat infections and one of the following:
    • Multiple antibiotic allergies/intolerances
    • PFAPA (periodic fever, aphthous stomatitis, pharyngitis, and adenitis)
    • History of >1 peritonsillar abscess

 

References 
  1. Shulman ST, Bisno AL, Clegg HW, Gerber MA, Kaplan EL, Lee G, Martin JM, Van Beneden C. 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):1279-82. 
  2. Mitchell RB, Archer SM, Ishman SL, Rosenfeld RM, Coles S, Finestone SA, Friedman NR, Giordano T, Hildrew DM, Kim TW, et al. Clinical practice guideline: Tonsillectomy in children (update). Otolaryngol Head Neck Surg 2019 Feb;160(1_suppl):S1-S42.

 

Case Studies

  1. A 19-year-old college student presented after several days of fever, sore throat and fatigue. He appears very tired with a temperature of 38.8 degrees Celsius. Physical examination demonstrates diffuse pharyngeal erythema with significantly enlarged tonsils and presence of tender anterior and posterior cervical adenopathy. What diagnosis do you suspect in this patient?  How would you further assess the etiology of his symptoms?  What next steps would you take in treatment of this patient?
  2. A 35 year-old elementary school teacher describes one week of fever, sore throat and malaise. She was treated conservatively with analgesics. She now has increased difficulty and pain with swallowing, muffled speaking voice and pain with opening of her mouth.  What exam findings would you expect to find in this patient? What further testing is necessary? How would you elect to treat this patient? What risks/benefits do you counsel her regarding the possibility of surgery?

Complications

Learning Objectives 
  1. Describe the suppurative complications of group A streptococcal pharyngitis: 
  • Peritonsillar or retropharyngeal abscess
  • Cervical lymphadenitis
  • Thrombophebitis of the internal jugular vein (Lemierre Syndrome)
  • Mastoiditis
  • Sinusitis
  • Otitis media
  1. Know the nonsuppurative complications of untreated strep pharyngitis:
  • Rheumatic fever 
    • 1-5 weeks after strep infection
    • Fever, joint pain, fatigue, chorea, nodules, cardiac complications
  • Acute poststreptococcal glomerulonephritis
    • Up to 3 weeks after strep infection
    • Proteinuria, hypertension, hematuria, lethargy, edema
  • Poststreptococcal reactive arthritis
  • Pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS)

 

References 
  1. Bisno AL. Acute pharyngitis. N Engl J Med 2001 Jan 18;344(3):205-11.
  2. Williams A, Nagy M, Wingate J, Bailey L, Wax M. Lemierre syndrome: A complication of acute pharyngitis. Int J Pediatr Otorhinolaryngol 1998 Sep 15;45(1):51-7.

 

Review

Review Questions 
  1. What are the presenting symptoms of pharyngitis?
  2. What factors on history are important to elicit in a patient with pharyngitis?
  3. What is the most common cause of acute pharyngitis?
  4. What diagnostic tests should be used to evaluate pharyngitis?
  5. What is the first step in management of pharyngitis?

 

Resources 

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  1. Patient Management Perspectives (PMP):
  1. eBooks: