Acute Pharyngitis


Epidemiology

Prevalence

  • Acute Pharyngitis is One of the Most Common Conditions Encountered in Outpatient Clinical Practice
    • Most Cases of Acute Pharyngitis are Caused by Respiratory Viruses and are Self-Limited
    • However, Acute Pharyngitis May Also Be Caused by Treatable Bacterial Infections (Such as Streptococcus Pyogenes)
  • Acute Pharyngitis Accounts for Approximately 12 Million Ambulatory Care Visits (or 1-2% of All Ambulatory Visits) Annually in the United States (Scand J Infect Dis, 2002) [MEDLINE]
  • Incidence of Acute Pharyngitis Peaks in Childhood/Adolescence (50% of Cases Occur Before Age 18) (Scand J Infect Dis, 2002) [MEDLINE] (Pediatrics, 2007) [MEDLINE]
    • In Adults, Most Cases of Acute Pharyngitis Occure Prior to Age 40 and the Incidence Decreases After Age 40

Etiology

Infection

Viral

  • General Comments
    • Respiratory Viruses are the Most Common Etiology of Acute Pharyngitis (Account for 25-45% of Pharyngitis Cases) (Ann Intern Med, 1989) [MEDLINE] (NEJM, 2001) [MEDLINE]
    • Patients with Pharyngitis Caused by Respiratory Viruses Usually Have Other Symptoms/Signs of Upper Respiratory Tract Infection (Such as Fatigue, Nasal Congestion, Cough, Coryza, Conjunctivitis, Sneezing, Hoarseness, Ear Pain, Sinus Discomfort, Oral Ulcers, and/or a Viral Exanthem)
  • Common Cold (see Common Cold)
    • Epidemiology
      • Pharyngitis Occurs Most Commonly as Part of the Common Cold Syndrome and is, Therefore, is Usually Associated with the Same Viruses Which Cause the Common Cold
    • Etiology
    • Clinical
      • Chills (see Chills): typically occurs early in the course (Arch Intern Med, 1958) [MEDLINE]
      • Coryza (Nasal Mucous Membrane Inflammation)
      • Cough (see Cough): less common than in influenza
      • Eustachian Tube Dysfunction (see Eustachian Tube Dysfunction): common
      • Fever (see Fever)
        • Fever is Uncommon in Adults (Transient Mild Hypothermia May Be Observed Early in the Course in Some Cases) (Arch Intern Med, 1958) [MEDLINE]
        • Fever May Occur in Children
      • Headache (see Headache): typically occurs early in the course (Arch Intern Med, 1958) [MEDLINE]
      • Malaise: typically occurs early in the course (Arch Intern Med, 1958) [MEDLINE]
      • Myalgias (see Myalgias): 50% of cases (Pain Med, 2003) [MEDLINE]
      • Nasal Obstruction: typically occurs later in the course (Arch Intern Med, 1958) [MEDLINE]
      • Pharyngitis: common and typically occurs early in the course (Arch Intern Med, 1958) [MEDLINE]
      • Rhinorrhea/Nasal Discharge (see Rhinorrhea): typically occurs later in the course (Arch Intern Med, 1958) [MEDLINE]
      • Sneezing (see Sneezing): typically occurs early in the course (Arch Intern Med, 1958) [MEDLINE]
  • Cytomegalovirus (CMV) (see Cytomegalovirus)
    • Epidemiology
      • Rare Etiology of Pharyngitis
    • Clinical
      • Heterophil Antibody-Negative Mononucleosis Syndrome with Acute or Chronic Non-Exudative Pharyngitis
        • Similar to Epstein-Barr Virus Infectious Mononucleosis (But Generally Milder or Absent Pharyngitis)
      • Oral Ulcerations (see Mucocutaneous Ulcers): may occur in immunosuppressed patients
      • Less Prominent Lymphadenopathy (As Compared to Epstein-Barr Virus Infectious Mononucleosis) (see Lymphadenopathy)
  • Epstein-Barr Virus (EBV) (Infectious Mononucleosis) (see Epstein-Barr Virus)
    • Epidemiology
      • Less Common Etiology of Pharyngitis
      • Most Commonly Occurs in Adolescents/Young Adults
    • Clinical
      • Epstein-Barr Virus Infectious Mononucleosis: symptoms may be prolonged (lasting 2-3 wks)
        • Acute Exudative Pharyngitis: common feature (occurs in 85% of cases) (Dis Mon, 1974) [MEDLINE]
        • Patchy Pharyngeal Exudates and Palatal Petechiae May Occur (Mimicking that Seen in Streptococcus Pyogenes Pharyngitis)
        • Tonsillar Swelling May Be Severe
        • Atypical Lymphocytosis (see Peripheral Blood Smear)
        • Cervical Lymphadenopathy (Tender, Symmetric Posterior) (see Lymphadenopathy)
        • Fatigue (see Fatigue)
        • Fever (see Fever)
        • Splenomegaly (see Splenomegaly)
  • Hemorrhagic Fever Viruses: pharyngitis may occur prior to development of skin lesions
    • Arenaviridae
      • Lassa Fever (Lassa Virus) (see Lassa Virus)
      • Lujo Virus
      • Argentine Hemorrhagic Fever (Junin Virus)
      • Bolivian Hemorrhagic Fever (Machupo Virus)
      • Brazilian Hemorrhagic Fever (Sabiá Virus)
      • Venezuelan Hemorrhagic Fever (Guanarito Virus)
    • Bunyaviridae
      • Hantavirus Genus Which C Hemorrhagic Fever with Renal Syndrome (HFRS)
      • Crimean-Congo Hemorrhagic Fever (CCHF) Virus (Nairovirus genus)
      • Garissa Virus and Ilesha Virus from the Orthobunyavirus
      • Rift Valley Fever Virus (Phlebovirus Genus)
    • Filoviridae
    • Flaviviridae
    • Rhabdoviridae
      • Rhabdoviruses
  • Herpes Simplex Virus (HSV) (see Herpes Simplex Virus)
    • Clinical
      • Primary Herpes Simplex Virus Infection in Children
      • Primary Herpes Simplex Virus Infection in Adults
        • Severe Exudative Pharyngitis (with Cervical Lymphadenopathy and Less Frequent Fever/Oropharyngeal Ulcers) (see Lymphadenopathy): primary Herpes-Simplex virus infection may account for as many as 5% of adult pharyngitis cases (Pediatr Infect Dis J, 1993) [MEDLINE]
  • Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus)
    • Epidemiology
      • Pharyngitis May Occur in the Setting of Primary Human Immunodeficiency Virus Infection
      • Risk is Increased in Patients with Demographic Risk Factors (Age 15-24 y/o, Men Who Have Sex with Men, History of Sexually-Transmitted Disease, Unmarried Status, Lowe Socioeconomic Status, High School Education or Less, Admission to Correctional Facility, Illicit Drug Use) and Behavioral Risk Factors (New Sex Partner in Past 60 Days, Multiple or Anonymous Sex Partners, Inconsistent Condom Use in Non-Monogamous Relationship, Trading Sex for Money for Drugs, Sexual Contact with Sex Workers)
    • Acute Retroviral Syndrome (i.e Symptomatic Acute HIV Infection): acute HIV infection is symptomatic in 40-90% of cases, symptoms occur 2-4 wks after infection (Curr Opin HIV AIDS, 2008)[MEDLINE]
      • Arthralgias (see Arthralgias)
        • Occur in 30% of Cases
      • Cervical Lymphadenopathy (see Lymphadenopathy)
        • Occurs in 39% of Cases
      • Diarrhea (see Diarrhea)
        • Occurs in 27% of Cases
      • Fatigue (see Fatigue)
        • Common Feature (Occurs in 68% of Cases)
      • Fever (see Fever)
        • Common Feature (Occurs in 75% of Cases)
      • Headache (see Headache)
        • Occurs in 45% of Cases
      • Maculopapular Rash (see Macules and Papules)
        • Occurs in 48% of Cases
      • Mucocutaneous Ulcers (Painful) (see Mucocutaneous Ulcers)
        • Common
        • Shallow, Sharply-Demarcated with White Base and Erythematous Perimeter
      • Myalgias (see Myalgias)
        • Occur in 49% of Cases
      • Night Sweats (see Night Sweats)
        • Occurs in 28% of Cases
      • Pharyngitis (Typically Without Pharyngeal Exudates)
        • Occurs in 40% of Cases
      • Weight Loss (see Weight Loss)
  • Influenza A/B Virus (see Influenza Virus)
    • Clinical
  • Reovirus (see Reovirus)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis (Prim Care, 1996) [MEDLINE]
  • Rotavirus (see Rotavirus)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis (Prim Care, 1996) [MEDLINE]
  • Rubella Virus (see Rubella Virus)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis (Prim Care, 1996) [MEDLINE]
  • Rubeola (Measles) Virus (see Rubeola Virus)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis (Prim Care, 1996) [MEDLINE]
  • Severe Acute Respiratory Syndrome Coronavirus-2 (COVID-19, SARS-CoV-2) (see Severe Acute Respiratory Syndrome Coronavirus-2)

Bacterial

  • Actinomyces (Actinomycosis) (see Actinomycosis)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis (Prim Care, 1996) [MEDLINE]
  • Arcanobacterium Haemolyticum (Formerly Corynebacterium Haemolyticum) (see Arcanobacterium Haemolyticum)
    • Epidemiology
      • Less Common
      • Accounts for Only 1-2.5% of Acute Pharyngitis Cases (Clin Infect Dis, 1995) [MEDLINE]
      • Typically Occurs in Adolescents/Young Adults
    • Clinical
      • Symptoms/Signs are Similar to Streptococcus Pyogenes (see Streptococcus Pyogenes)
      • Scarlatiniform Rash (Particularly in Adolescents/Young Adults) Occurs in 50% of Cases
      • Severe, Invasive Infections Have Been Rarely Reported
  • Chlamydia Pneumoniae (see Chlamydia Pneumoniae)
    • Epidemiology
      • Rare
      • Typically Occurs in Children/Young Adults (J Med Microbiol, 2004) [MEDLINE]
    • Clinical
  • Corynebacterium Diphtheriae (Diphtheria) (see Diphtheria)
    • Epidemiology
      • Rare in the United States (Higher Incidence with Occasional Outbreaks in Less Developed Countries with Lower Vaccination Rates)
      • Occurs in Patient who Has Not Been Vaccinated for Diphtheria
    • Clinical
      • Diphtheria: symptom onset is typically gradual
        • Anorexia (see Anorexia)
        • Cervical Lymphadenopathy (see Lymphadenopathy)
        • Adherent Gray-White Membrane on Palate/Tonsil/Posterior Oropharynx (Which Bleeds When Dislodged): occurs in 33% of cases
        • Low-Grade Fever (see Fever)
        • Malaise
        • Sore Throat
  • Francisella Tularensis (Tularemia-Pharyngeal/Oropharyngeal) (see Tularemia)
    • Epidemiology
      • Rare
      • Typically Associated with Ingestion of Contaminated Food or Water (Comp Immunol Microbiol Infect Dis, 2014) [MEDLINE] (MMWR Morb Mortal Wkly Rep, 2015) [MEDLINE]
    • Clinical
      • Ulceroglandular Fever
        • Painful Cervical Lymphadenopathy (Particularly Posterior and Bilateral) (see Lymphadenopathy)
        • Oral Ulcers (see Mucocutaneous Ulcers)
        • Exudative Pharyngitis
        • Pharyngeal Membrane (May Be Present in Some Cases)
        • Severe Sore Throat
  • Fusobacterium Necrophorum (see Fusobacterium Necrophorum)
    • Epidemiology
      • Unclear Incidence
      • Possible Association with Recurrent or Persistent Pharyngitis
    • Physiology
      • Fusobacterium Necrophorum is an Anaerobe Which May Colonizes the Oropharynx (in 2-10% of Normal Young Adults) and is Considered a Putative Cause of Pharyngitis
        • Rates of Oropharyngeal Detection is Higher (15-20% of Cases) of Adults with Acute Pharyngitis
        • Rates of Oropharyngeal Detection is Even Higher (45% of Cases) of Adults with Recurrent Pharyngitis
        • Co-Pathogens are Frequently Also Detected with Fusobacterium Necrophorum
      • However, Fusobacterium Necrophorum is Considered a True Pathogen in Lemierre’s Syndrome
    • Clinical
      • Lemierre’s Syndrome (see Lemierre’s Syndrome)
        • Normal Pharynx or Pharyngeal Ulcers/Pseudomembrane
        • Septic Jugular Vein Thrombophlebitis
  • Leptospira (Leptospirosis) (see Leptospirosis)
  • Mixed Anaerobes
  • Mycoplasma Pneumoniae (see Mycoplasma Pneumoniae)
  • Neisseria Gonorrhoeae (see Neisseria Gonorrhoeae)
    • Epidemiology
      • Rare Etiology of Pharyngitis
      • Most Commonly Occurs in a Patient with Risk Factors for Sexually-Transmitted Infections (Particularly Receptive Oral Intercourse)
    • Clinical
      • Pharyngeal Gonorrhea: prevalence may be as high as 15% in men who have sex with men (however, most cases are asymptomatic)
        • Nonspecific Symptoms
        • Acute Sore Throat
        • Pharyngeal Exudates
        • Cervical Lymphadenopathy (see Lymphadenopathy)
  • Streptobacillus Moniliformis (Rat Bite Fever) (see Rat Bite Fever)
    • Microbiology
      • Streptobacillus Moniliformis
      • Streptobacillus Notomytis
      • Spirillum Minus
    • Clinical
  • Streptococcus-Group C or G (see Group C + Group G Streptococcus)
    • Epidemiology
      • Less Common Etiology of Acute Pharyngitis than Streptococcus Pyogenes
      • Account for 5-10% of Acute Pharyngitis Cases (J Clin Microbiol. 1997) [MEDLINE] (Clin Infect Dis, 2012) [MEDLINE] (Ann Intern Med, 2015) [MEDLINE]
      • Most Common in College Students/Young Adults
      • Has Been Associated with Foodborne/Waterborne Outbreaks
    • Clinical
      • Symptoms/Signs are Similar to Streptococcus Pyogenes (see Streptococcus Pyogenes)
      • No Association with Acute Rheumatic Fever or Other Immune-Associated Complications
  • Streptococcus Pyogenes (Group A Streptococcus) (see Streptococcus Pyogenes)
    • Epidemiology
      • Most Common Bacterial Etiology of Acute Pharyngitis
      • Accounts for 5-15% of Acute Pharyngitis Cases in Developed Countries (Clin Infect Dis, 2012) [MEDLINE]
        • Rates are Higher in Less Developed Countries
      • Commonly Occurs in Younger Adults
      • Risk Increases with Exposure to Others with Streptococcus Pyogenes Pharyngitis
    • Clinical
      • Acute Onset of Sore Throat
      • Fever (see Fever)
      • Palatal Petechiae
      • Pharyngeal Edema
      • Scarlatiniform Rash (Particularly in Adolescents/Young Adults)
      • Strawberry Tongue
      • Tender Cervical Lymphadenopathy (Commonly Anterior) (see Lymphadenopathy)
      • Tonsillar Exudates (Patchy)
      • Complications
        • Suppurative: otitis media, peritonsillar cellulitis or abscess, sinusitis, meningitis, bacteremia, necrotizing fasciitis
        • Non-Suppurative: acute rheumatic fever, poststreptococcal glomerulonephritis, reactive arthritis
  • Treponema Pallidum (Syphilis) (see Syphilis)
    • Epidemiology
      • Rare Etiology of Pharyngitis
      • Syphilis Rates are Increasing in Men Who Have Sex with Men and in Patients with HIV Infection (PLoS One, 2016) [MEDLINE]
    • Clinical
      • Secondary Syphilis: onset is weeks-months after exposure
        • Generalized Lymphadenopathy (see Lymphadenopathy)
        • Mucous Patches on the Oral Mucosa and Tongue (Round/Oval Elevated Lesion, Covered by a Pink-Gray Membrane)
        • Pharyngitis is Common (Occurs in 50% of Secondary Syphilis Cases): sore throat may precede the mucosal ulcers, generalized lymphadenopathy and palmar-plantar rash
        • Rash on Palms/Soles (Palmar-Plantar Rash)

Fungal

  • Blastomyces Dermatitidis (Blastomycosis) (see Blastomycosis)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis
  • Cryptococcus Neoformans (Crytptococcosis) (see Crytptococcosis)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis
  • Histoplasma Capsulatum (Histoplasmosis) (see Histoplasmosis)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis
  • Oropharyngeal Thrush/Candidiasis (see Candida)
    • Epidemiology
  • Paracoccidoides Brasiliensis (Paracoccidioidomycosis) (see Paracoccidioidomycosis)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis
  • Rhinosporidium Seeberi (see Rhinosporidium Seeberi)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis

Parasitic

  • Toxoplasma Gondii (Toxoplasmosis) (see Toxoplasmosis)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis

Drugs

Other

  • Adult-Onset Still’s Disease (see Adult-Onset Still’s Disease)
  • Allergic Rhinitis (see Allergic Rhinitis)
    • Epidemiology
      • Common Non-Infectious Etiology of Pharyngitis
  • Behcet’s Disease (see Behcet’s Disease)
  • Dry Air
    • Epidemiology
      • Common During Winter Months
  • Endotracheal Intubation (see Endotracheal Intubation and Invasive Mechanical Ventilation-Adverse Effects)
    • Epidemiology
      • Pharyngitis/Sore Throat is Common Following Endotracheal Intubation (Anesth Analg, 2010) [MEDLINE]
  • Gastroesophageal Reflux Disease (GERD) (see Gastroesophageal Reflux Disease)
    • Epidemiology
      • Common Etiology of Non-Infectious Pharyngitis
    • Clinical
      • Chronic Pharyngitis
  • Kawasaki Disease (see Kawasaki Disease)
    • Epidemiology
      • Kawasaki Disease Frequently Presents with Pharyngitis in Both Children and Adults
  • Environmental/Occupational/Hazard-Associated Irritants
    • Epidemiology
      • Air Pollution (see Air Pollution)
      • Dust Exposure
      • Exposure to Brick Kilns, Cement Works, Factory Exhaust Emissions, Pulp Mills, Woodworking, etc
      • Exposure to Cooking/Fires
      • Exposure to Boron Acid, Boron Oxide, Borax Dust, Crude Oil Spills, Fluorinated Hydrocarbons, Machine Coolants (in Metal Working Industries), Nitrogen Trichloride (in Indoor Swimming Pools), Organic Screen Printing Solvents, Solvents in Newspaper Industry, etc
      • Exposure to Volcano Eruption (Due to Sulfur Dioxide and Particulates)
      • Ingestion of Caustic Substance
      • Smoke Inhalation (see Smoke Inhalation)
  • Periodic Fever + Aphthous Stomatitis + Pharyngitis + Adenitis (PFAPA) Syndrome
    • Epidemiology
      • Usually Starts in Young Children
  • Radiation Therapy (see Radiation Therapy)
  • Snoring (see Snoring)
    • Epidemiology
      • Snoring is Frequently Associated with Sore Throat
  • Systemic Lupus Erythematosus (SLE) (see Systemic Lupus Erythematosus)
    • Epidemiology
      • Rare Etiology of Acute Pharyngitis
  • Thyroiditis (see Thyroiditis)
    • Epidemiology
      • Approximately 40% of Patients with Thyroiditis Report Sore Throat as the First Symptom
    • Physiology
      • Referred Pain
  • Tobacco Smoke Exposure (see Tobacco)
    • Epidemiology
      • Associated with Either Smoking or Second-Hand Smole Exposure
  • Vocal Strain/Shouting
    • Epidemiology
      • Sore Throat/Pharyngitis is Common with Vocal Strain (Due to Excessive Speaking, etc) (Codas, 2016) [MEDLINE] (J Voice, 2016) [MEDLINE]

Physiology

Pain of Pharyngitis

  • Mediated by Kinins (Which are Potent Stimulators of Nerve Endings)
    • Bradykinin is Present in Nasal Secretions in the Common Cold
      • Experimental Topical Application of Bradykinin Induces a Sore Throat and Nasal Symptoms
    • Lysylbradykinin is Present in Nasal Secretions in the Common Cold

Diagnosis

Oropharyngeal (Throat) Swab with Rapid Antigen Detection Test (RADT) for Streptococcus Pyogenes (see Streptococcus Pyogenes)

General Comments

  • For Most Adults with Suspected Streptococcus Pyogenes Pharyngitis, Testing with Rapid Antigen Detection Test is Sufficient to Establish the Diagnosis (Clin Infect Dis, 2012) [MEDLINE
    • In Patient with a Negative Rapid Antigen Detection Test for Streptococcus Pyogenes, Further Testing with Oropharyngeal Culture is Indicated for Specific Groups of Patients (See Below)

Recommendations (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) [MEDLINE]

  • How Should the Diagnosis of Streptococcus Pyogenes Pharyngitis Be Established?
    • Oropharyngeal Swab Testing for Streptococcus Pyogenes Pharyngitis (Rapid Antigen Detection Test and/or Oropharyngeal Culture for Streptococcus Pyogenes) Should Be Performed Since Clinical Features Alone Do Not Reliably Discriminate Between Streptococcus Pyogenes Pharyngitis and Viral Pharyngitis (Except When Overt Viral Clinical Features Such as Rhinorrhea, Cough, Oral Ulcers, and/or Hoarseness are Present)
      • In Children/Adolescents, a Negative Rapid Antigen Detection Test for Streptococcus Pyogenes Should Be Followed by a Oropharyngeal Culture for Streptococcus Pyogenes (Strong Recommendation, High Quality of Evidence)
      • A Positive Rapid Antigen Detection Test for Streptococcus Pyogenes Does Not Necessitate a Back-Up Oropharyngeal Culture Because the Rapid Antigen Detection Test is Highly Specific (Strong Recommendation, High Quality of Evidence)
    • For Those with a Negative Rapid Antigen Detection Test for Streptococcus Pyogenes, Routine Use of Back-Up Oropharyngeal Culture for Streptococcus Pyogenes is Not Necessary for Adults (with the Exceptions Discussed Below), Because of the Low Incidence of Streptococcus Pyogenes Pharyngitis in Adults and Because the Risk of Subsequent Acute Rheumatic Fever is Generally Exceptionally Low in Adults with Acute Pharyngitis (Strong Recommendation, Moderate Quality of Evidence)
      • Physicians Who Wish to Ensure that They are Achieving Maximal Sensitivity in Diagnosis May Continue to Use Conventional Oropharyngeal Culture for Streptococcus Pyogenes or to Back-Up a Negative Rapid Antigen Detection Test for Streptococcus Pyogenes with a Subsequent Oropharyngeal Culture for Streptococcus Pyogenes
    • Anti-Streptococcal Antibody Titers are Not Recommended in the Routine Diagnosis of Acute Pharyngitis as They Reflect Past But Not Current Events (Strong Recommendation, High Quality of Evidence)
  • Who Should Undergo Testing for Streptococcus Pyogenes Pharyngitis?
    • Testing for Streptococcus Pyogenes Pharyngitis is Not Usually Recommended for Children/Adults with Acute Pharyngitis with Clinical and Epidemiological Features Which Strongly Suggest a Viral Etiology (Rhinorrhea, Cough, Oral Ulcers, and/or Hoarseness) (Strong Recommendation, High Quality of Evidence)
    • Diagnostic Studies for Streptococcus Pyogenes Pharyngitis are Not Indicated for Children <3 y/o Because Acute Rheumatic Fever is Rare in Children <3 y/o and the Incidence of Streptococcal Pharyngitis and the Classic Presentation of Streptococcal Pharyngitis are Uncommon in this Age Group
      • Selected Children <3 y/o Who Have Other Risk Factors (Such as an Older Sibling with Streptococcus Pyogenes Infection) May Be Considered for Testing (Strong Recommendation, Moderate Quality of Evidence)
    • Follow-Up Post-Treatment Oropharyngeal Cultures for Streptococcus Pyogenes or Rapid Antigen Detection Test for Streptococcus Pyogenes are Not Recommended Routinely But May Be Considered in Special Circumstances (Strong Recommendation, High Quality of Evidence)
    • Diagnostic Testing or Empiric Treatment of Asymptomatic Household Contacts of Patients with Acute Streptococcal Pharyngitis is Not Routinely Recommended (Strong Recommendation, Moderate Quality of Evidence)

Oropharyngeal (Throat) Culture (see Oropharyngeal Culture)

General Comments

  • For Most Adults with Suspected Streptococcus Pyogenes Pharyngitis, Testing with Rapid Antigen Detection Test (See Above) is Sufficient to Establish Diagnosis (Clin Infect Dis, 2012) [MEDLINE
    • However, the Following Patients with a Negative Rapid Antigen Detection Test for Streptococcus Pyogenes Should Undergo Further Testing to Definitively Exclude the Diagnosis of Streptococcus Pyogenes Pharyngitis
      • Patient at Hight Risk for Severe Infection or Complications from Streptococcus Pyogenes Pharyngitis
        • Immunocompromised State
        • Patient with History of Acute Rheumatic Fever
      • Patient in Close Contact with Individual at Hight Risk for Complications
        • Patient Caring for Infants or Living with Immunocompromised Individuals)
      • Young Adult Patient Living in College Dormitory or Other Setting Where the prevalence of Streptococcus Pyogenes Pharyngitis is Higher than that of the General Adult Population
      • Patient Living in Area where Acute Rheumatic Fever is Endemic or Where There is an Active Acute Rheumatic Fever Epidemics
      • Patient in Whom Clinical Suspicion for Streptococcus Pyogenes is High Despite a Negative Rapid Antigen Detection Test
        • Person with Centor Score ≥3 Who Have Additional Risk Factors for Streptococcus Pyogenes Pharyngitis (Such as Exposure to a Person with Streptococcus Pyogenes Infection)

Technique

  • Oropharyngeal Culture Samples Should Be Obtained Prior to Antibiotic Administration to maximize Diagnostic Yield (Pediatr Infect Dis J, 1987) [MEDLINE] (Pediatrics, 1993) [MEDLINE]
  • Specimen Collection Requires Vigorous Swabbing of Both Tonsils (or Tonsillar Fossa, in Those with Prior Tonsillectomy) and Posterior Pharynx
    • Specimens Collected from the Tongue, Buccal Mucosa, or Hard Palate are Not Adequate
    • Sensitivity of Oropharyngeal Culture Correlates with the Bacterial Inoculum Obtained by Swabbing
    • Streptococcus Pyogenes Remains Viable on Dry Swabs for Approximately 48-72 hrs After Collection
      • Therefore, a Second Swab Collected for Rapid Antigen Detection Test Can Be Later Sent for Culture After the Rapid Antigen Detection Test Has Resulted
    • Oropharyngeal Culture Generally Requires Around 24-48 hrs
    • Due to Short Processing Time Required, Empiric Treatment is Not Recommended (Since Short Delay in Initiating Antibiotic Therapy for Streptococcus Pyogenes Infection is Not Generally Associated with Increased Complication Rates)
  • Sensitivity/Specificity with Proper Collection/Processing (Clin Infect Dis, 2012) [MEDLINE]
    • Sensitivity: 90-95%
    • Specificity: 95-99%

Recommendations (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) [MEDLINE]

  • How Should the Diagnosis of Streptococcus Pyogenes Pharyngitis Be Established?
    • Oropharyngeal Swab Testing for Streptococcus Pyogenes Pharyngitis (Rapid Antigen Detection Test and/or Oropharyngeal Culture for Streptococcus Pyogenes) Should Be Performed Since Clinical Features Alone Do Not Reliably Discriminate Between Streptococcus Pyogenes Pharyngitis and Viral Pharyngitis (Except When Overt Viral Clinical Features Such as Rhinorrhea, Cough, Oral Ulcers, and/or Hoarseness are Present)
      • In Children/Adolescents, a Negative Rapid Antigen Detection Test for Streptococcus Pyogenes Should Be Followed by a Oropharyngeal Culture for Streptococcus Pyogenes (Strong Recommendation, High Quality of Evidence)
      • A Positive Rapid Antigen Detection Test for Streptococcus Pyogenes Does Not Necessitate a Back-Up Oropharyngeal Culture Because the Rapid Antigen Detection Test is Highly Specific (Strong Recommendation, High Quality of Evidence)
    • For Those with a Negative Rapid Antigen Detection Test for Streptococcus Pyogenes, Routine Use of Back-Up Oropharyngeal Culture for Streptococcus Pyogenes is Not Necessary for Adults (with the Exceptions Discussed Below), Because of the Low Incidence of Streptococcus Pyogenes Pharyngitis in Adults and Because the Risk of Subsequent Acute Rheumatic Fever is Generally Exceptionally Low in Adults with Acute Pharyngitis (Strong Recommendation, Moderate Quality of Evidence)
      • Physicians Who Wish to Ensure that They are Achieving Maximal Sensitivity in Diagnosis May Continue to Use Conventional Oropharyngeal Culture for Streptococcus Pyogenes or to Back-Up a Negative Rapid Antigen Detection Test for Streptococcus Pyogenes with a Subsequent Oropharyngeal Culture for Streptococcus Pyogenes
    • Anti-Streptococcal Antibody Titers are Not Recommended in the Routine Diagnosis of Acute Pharyngitis as They Reflect Past But Not Current Events (Strong Recommendation, High Quality of Evidence)
  • Who Should Undergo Testing for Streptococcus Pyogenes Pharyngitis?
    • Testing for Streptococcus Pyogenes Pharyngitis is Not Usually Recommended for Children/Adults with Acute Pharyngitis with Clinical and Epidemiological Features Which Strongly Suggest a Viral Etiology (Rhinorrhea, Cough, Oral Ulcers, and/or Hoarseness) (Strong Recommendation, High Quality of Evidence)
    • Diagnostic Studies for Streptococcus Pyogenes Pharyngitis are Not Indicated for Children <3 y/o Because Acute Rheumatic Fever is Rare in Children <3 y/o and the Incidence of Streptococcal Pharyngitis and the Classic Presentation of Streptococcal Pharyngitis are Uncommon in this Age Group
      • Selected Children <3 y/o Who Have Other Risk Factors (Such as an Older Sibling with Streptococcus Pyogenes Infection) May Be Considered for Testing (Strong Recommendation, Moderate Quality of Evidence)
    • Follow-Up Post-Treatment Oropharyngeal Cultures for Streptococcus Pyogenes or Rapid Antigen Detection Test for Streptococcus Pyogenes are Not Recommended Routinely But May Be Considered in Special Circumstances (Strong Recommendation, High Quality of Evidence)
    • Diagnostic Testing or Empiric Treatment of Asymptomatic Household Contacts of Patients with Acute Streptococcal Pharyngitis is Not Routinely Recommended (Strong Recommendation, Moderate Quality of Evidence)

Polymerase Chair Reaction (PCR) Assay for Streptococcus Pyogenes

General Comments

  • PCR-Based Assays for Streptococcus Pyogenes are More Sensitive than Rapid Antigen Detection Tests for Streptococcus Pyogenes and Oropharyngeal Culture for Streptococcus Pyogenes (Particularly When the Bacterial Burden is Low (J Clin Microbiol, 2016) [MEDLINE]
    • However, PCR-Based Assays for Streptococcus Pyogenes are Not Routinely Available in Clinical Practice

Diagnostic Testing for Pathogens Other than Streptococcus Pyogenes

  • Diagnostic Testing for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) (see Severe Acute Respiratory Syndrome Coronavirus-2)
    • In Any Patient Presenting with an Acute Respiratory Illness, Oropharyngeal Swab with Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) Testing for SARS-CoV-2 is Required for the Purpose of Infection Control
  • Diagnostic Testing for Epstein-Barr Virus (see Epstein-Barr Virus)
    • Should Be Performed in Patient with Infectious Mononucleosis-Like Syndrome
  • Diagnostic Testing for Cytomegalovirus (CVM( (see Cytomegalovirus)
    • Should Be Performed in Patient with Infectious Mononucleosis-Like Syndrome
  • Diagnostic Testing for Herpes-Simplex Virus (HSV) (see Herpes-Simplex Virus)
    • Should Be Considered in Patient with Severe Sore Throat (Especially in Young Adult with Oral/Gingival Ulcers)
  • Diagnostic Testing for Streptococcus-Group C or G, Arcanobacterium Haemolyticum, and/or Fusobacterium Necrophorum (see Group C + Group G Streptococcus, Arcanobacterium Haemolyticum, and Fusobacterium Necrophorum)
    • Should Be Performed in Patient with Non-Streptococcus Pyogenes Pharyngitis Who Does Not Clinically Respond to Symptomatic Therapy within 5-7 Days (Clin Infect Dis, 2012) [MEDLINE]
  • Diagnostic Testing for Corynebacterium Diphtheriae (Diphtheria) (see Diphtheria)
    • Should Be Considered in Patient with Appropriate Clinical Risk Factors
  • Diagnostic Testing for Francisella Tularensis (Tularemia) (see Tularemia)
    • Should Be Considered in Patient with Appropriate Clinical Risk Factors
  • Diagnostic Testing for Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus) –Combination Antigen/Antibody Immunoassay (and HIV Viral Load Test) is the Preferred Mode of Testing
  • Diagnostic Testing for Neisseria Gonorrhoeae (see Neisseria Gonorrhoeae)
    • Pharyngeal Swab Testing for Nucleic Acid Amplification test (NAAT) for Neisseria Gonorrhoeae is the Preferred Diagnostic Test for gonococcal Pharyngitis
  • Diagnostic Testing for Syphilis (see Syphilis)
    • Standard Methods
  • Screening for Sexually-Transmitted Infection (STI’s)
    • Standardized Screening for Sexually-Transmitted Infections (Neisseria Gonorrhoeae, Chlamydia Trachomatis, etc) is Determined by the Presence of Various Risk Factors (see Urethritis)

Clinical Differentiation of Upper Respiratory Tract Infection vs Lower Respiratory Tract Infection

Clinical Manifestations

Otolaryngologic Manifestations

Pharyngeal Exudates

  • Clinical Features of Viral Pharyngitis
    • Pharyngeal Exudates are Typically Absent in Pharyngitis Due to Rhinovirus, Coronavirus, Influenza Virus, and Respiratory Syncytial Virus
      • Pharyngeal Exudates May Occur in Adenovirus Pharyngitis (see Adenovirus)
      • Pharyngeal Exudates are Prominent (and Palatal Petechiae May Occur) in Epstein-Barr Virus Infectious Mononucleosis (see Epstein-Barr Virus)
      • Pharyngeal Exudates are Prominent in Primary Herpes Simplex Virus Infection in Adults (see Herpes Simplex Virus)
  • Clinical Features of Bacterial Pharyngitis
    • In General, Pharyngeal Exudates are More Prominent
      • Pharyngeal Exudates are Prominent in Arcanobacterium Haemolyticum Pharyngitis (see Arcanobacterium Haemolyticum)
      • Pharyngeal Pseudomomembrane is Prominent in Corynebacterium Diphtheriae Pharyngitis (see Diphtheria)
      • Pharyngeal Ulcers/Pseudomomembrane May Occur in Lemierre’s Syndrome (see Lemierre’s Syndrome)
      • Pharyngeal Exudates are Prominent in in Mixed Anaerobic Infection (Vincent’s Angina, Peritonsillar Abscess)
      • Pharyngeal Exudates are Prominent in Neisseria Gonorrhoeae Pharyngitis (see Neisseria Gonorrhoeae)
      • Pharyngeal Exudates are Prominent in Streptococcus-Group C or G Pharyngitis (see Group C + Group G Streptococcus)
      • Pharyngeal Exudates are Prominent in Streptococcus Pyogenes Pharyngitis (see Streptococcus Pyogenes)
      • Pharyngeal Exudates are Prominent in Tularemia (see Tularemia)

Other Manifestations

Cervical Lymphadenopathy (see Lymphadenopathy)

  • Clinical Features of Viral Pharyngitis
    • In General, Cervical Lymphadenopathy May Be Present, But is Not Prominent
      • Cervical Lymphadenopathy is Present (But Less Prominent) in Cytomegalovirus Infectious Mononucleosis (see Cytomegalovirus)
      • Cervical Lymphadenopathy is Prominent in Epstein-Barr Virus Infectious Mononucleosis (see Epstein-Barr Virus)
      • Cervical Lymphadenopathy is Prominent in Primary Herpes Simplex Virus Infection in Adults (see Herpes Simplex Virus)
      • Cervical Lymphadenopathy is Prominent in Acute Human Immunodeficiency Virus (HIV) Infection (see Human Immunodeficiency Virus)
    • Clinical Features of Bacterial Pharyngitis
    • In General, Cervical Lymphadenopathy is More Prominent
      • Cervical Lymphadenopathy is Prominent in Corynebacterium Diphtheriae Pharyngitis (see Diphtheria)
      • Cervical Lymphadenopathy is Prominent in Streptococcus-Group C or G Pharyngitis (see Group C + Group G Streptococcus)
      • Cervical Lymphadenopathy is Prominent in Streptococcus Pyogenes Pharyngitis (see Streptococcus Pyogenes)
      • Cervical Lymphadenopathy is Prominent in Syphilis (see Syphilis)
      • Cervical Lymphadenopathy is Prominent in Tularemia (see Tularemia)

Fever (see Fever)

  • Clinical Features of Viral Pharyngitis
    • In Viral Upper Respiratory Tract Infection (Due to Common Cold, etc), Fever is Typically Low-Grade (or Absent), with the Following Exceptions
  • Clinical Features of Bacterial Pharyngitis

Clinical Differentiation of Streptococcus Pyogenes Pharyngitis vs Viral Pharyngitis

General Comments

  • This Clinical Differentiation is Critical, Due to the Need to Determine if Antibiotics are Indicated

General Clinical Features Which May Aid in Differentiation

  • Clinical Features Favoring the Diagnosis of Streptococcus Pyogenes Pharyngitis
    • Anterior, Tender Cervical Lymphadenopathy (see Lymphadenopathy)
    • Fever (see Fever)
    • History of Streptococcus Pyogenes Exposure
    • Patchy Tonsillar/Pharyngeal Exudates
    • Scarlatiniform Skin Rash and/or Strawberry Tongue (Scarlet Fever)
    • Sudden-Onset Sore Throat
    • Tonsillopharyngeal and/or Uvular Edema
  • Clinical Features Favoring the Diagnosis of Viral Pharyngitis

Centor Criteria (Endorsed by the European Society of Clinical Microbiology and Infectious Diseases) (Clin Microbiol Infect, 2012) [MEDLINE]

  • General Comments
    • One Point is Given for Each Criterion
    • The Likelihood of Streptococcus Pyogenes Pharyngitis Increases as the Total Points Rise
    • Patients with <3 Points are Unlikely to Have Streptococcus Pyogenes Pharyngitis and Generally Do Not Require Testing or Treatment
    • Patients with Score ≥2-3 May Benefit from Testing
    • Centor Criteria are Not Sensitive Nor Specific for the Diagnosis of Streptococcus Pyogenes Pharyngitis
      • These Criteria Should Be Used to Guide Streptococcus Pyogenes Testing, But Should Not Be Used to Determine if Antibiotics Should Be Prescribed
  • Absence of Cough
  • Fever (see Fever)
  • Tender Anterior Cervical Lymphadenopathy (see Lymphadenopathy)
  • Tonsillar Exudates

Clinical Symptoms/Signs Suggesting Need for Urgent Management

Specific Clinical Diagnoses Requiring Urgent Management

  • Epiglottitis (see Epiglottitis)
    • Drooling (see Drooling)
    • Fever (see Fever)
    • Hoarseness (see Hoarseness)
    • Muffled Voice
    • Respiratory Distress
    • Sore Throat (Severity Often Out of Proportion to Exam)
    • Stridor (see Stridor)
  • Lemierre’s Syndrome (see Lemierre’s Syndrome)
  • Ludwig’s Angina (Submandibular Abscess) (see Ludwig’s Angina)
    • Drooling (see Drooling)
    • Dysphagia (see Dysphagia)
    • Elevated Floor of Oropharynx
    • Fever/Rigors (see Fever)
    • Mouth Pain
    • Stiff Neck
    • Symmetric Induration/Palpable Crepitus of Submandibular Area
    • Absence of Trismus
  • Parapharyngeal Space Infection
    • Carotid Sheath Involvement
    • Dyspnea (see Dyspnea): due to swelling of epiglottis and larynx
    • Fever/Rigors (see Fever)
    • Medial Bulging of the Pharyngeal Wall
    • Swelling Below Angle of Mandible
    • Trismus (see Trismus)
  • Peritonsillar Abscess (Quinsy) (see Deep Neck Infection)
    • Drooling (see Drooling)
    • Fever (see Fever)
    • Otalgia (Ear Pain) (see Otalgia)
    • Muffled Voice
    • Neck Pain/Swelling
    • Severe Sore Throat (Usually Unilateral)
    • Severely Swollen/Fluctuant Tonsil with Deviation of Uvula (or Bulging of Soft Palate Near Tonsil)
    • Trismus (see Trismus)
  • Retropharyngeal Abscess
    • Dysphagia (see Dysphagia)
    • History of Penetrating Trauma to Oropharynx
    • Severe Sore Throat

Symptoms/Signs Below Indicate the Need for Urgent Management/Hospital Admission

  • Signs of Upper Airway Obstruction (see Obstructive Lung Disease)
    • Drooling/Pooling of Saliva
    • Hoarseness (see Hoarseness)
    • Muffled/”Hot Potato” Voice
    • Respiratory Distress (Dyspnea, Retractions, Tachypnea) (see Dyspnea and Tachypnea)
    • Stridor (see Stridor)
    • “Sniffing Position”/”Tripod” Position” (Both of Which Assist in Maintaining Airway Patency)
  • Signs of Deep Neck Infection (see Deep Neck Infection)
    • Bulging of Pharyngeal Wall/Soft Palate/Floor of Oropharynx
    • Crepitus
    • Fever/Rigors (see Fever)
    • History of Penetrating Trauma to Oropharynx
    • Neck Pain/Swelling
    • Severe Unilateral Sore Throat
    • Stiff Neck
    • Toxic Appearance
    • Trismus (Irritation and Reflex Spasm of the Internal Pterygoid Muscle) (see Trismus)

Treatment

Treatment of Acute Viral Pharyngitis

Supportive Care

  • Antibiotics are Contraindicated in Acute Viral Pharyngitis and Most Patients with Recover within 5-7 Days without Specific Therapy, (Ann Intern Med, 2001) [MEDLINE]
  • Failure to Clinically Improve

Treatment of Streptococcus Pyogenes (Group A Streptococcus) Pharyngitis

Antibiotic Therapy

  • Patients with Documented Streptococcus Pyogenes Pharyngitis Generally Recover within 24-74 hrs of Starting Antibiotics
  • Failure to Clinically Improve
    • In Patients with Positive Rapid Antigen Detection Testing for Streptococcus Pyogenes and a Lack of Clinical Improvement, Suppurative Complications (Peritonsillar Abscess, etc) or an Alternative Diagnosis Superimposed on Streptococcus Pyogenes Chronic Carriage Should Be Considered (Clin Infect Dis, 2012) [MEDLINE]

Recommendations (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) [MEDLINE]

  • Patients with Acute Streptococcus Pyogenes Pharyngitis Should Be Treated with an Appropriate Antibiotic (at Appropriate Dose) Usually for 10 Days to Eradicate the Organism from the Oropharynx
    • In Patients Who are Not Penicillin-Allergic, Penicillin/Amoxicillin are the Recommended First-Line Antibiotics for the Treatment of Streptococcus Pyogenes Pharyngitis (Strong Recommendation, High Quality of Evidence)
      • This Recommendation is Based on the Narrow Spectrum of Activity, Infrequency of Adverse Reactions, and Modest Cost of Penicillins
    • In Patients Who are Penicillin-Allergic, Treatment of Streptococcus Pyogenes Pharyngitis Should Include One of the Following (Strong Recommendation, Moderate Quality of Evidence)
      • For Those Not Anaphylactically Penicillin-Sensitive, First-Generation Cephalosporin x 10 Days (see Cephalosporins)
      • For Those Not Anaphylactically Penicillin-Sensitive, Clindamycin x 10 Days (see Clindamycin)
      • For Those Not Anaphylactically Penicillin-Sensitive, Azithromycin x 5 Days (see Azithromycin)
      • For Those Not Anaphylactically Penicillin-Sensitive, Clarithromycin x 10 Days (see Clarithromycin)
  • If Warranted (and Not Contraindicated), Adjunctive Use of an Analgesic/Antipyretic (Acetaminophen, NSAID) for the Treatment of Moderate-Severe Symptoms or Control of High Fever Should Be Considered in Addition to Antibiotic Therapy in the Treatment of Streptococcus Pyogenes Pharyngitis (Strong Recommendation, High Quality of Evidence)
    • Aspirin Should Be Avoided in Children (Strong Recommendation, Moderate Quality of Evidence)
  • Adjunctive Therapy with a Corticosteroid is Not Recommended in the Treatment of Streptococcus Pyogenes Pharyngitis (Weak Recommendation, Moderate Quality of Evidence)
  • Relationship Between Recurrent Episodes of Apparent Streptococcus Pyogenes Pharyngitis and Chronic Pharyngeal Streptococcus Pyogenes Carriage
    • Clinicians Caring for Patients with Recurrent Episodes of Pharyngitis Associated with Laboratory Evidence of Streptococcus Pyogenes Pharyngitis Should Consider that the Patient May Be Experiencing >1 Episode of Bona Fide Streptococcal Pharyngitis at Close Intervals, But They Should Also Be Alert to the Possibility that the Patient May Actually Be a Chronic Pharyngeal Streptococcus Pyogenes Carrier Who is Experiencing Repeated Viral Pharyngitis (Strong Recommendation, Moderate Quality of Evidence)
    • Streptococcus Pyogenes Carriers Do Not Ordinarily Justify Efforts to Identify Them, Nor Do They Generally Require Antimicrobial Therapy Because Streptococcus Pyogenes Carriers are Unlikely to Spread Streptococcus Pyogenes Pharyngitis to Their Close Contacts and are at Little or No Risk for Developing Suppurative or Non-Suppurative Complications (Such as Acute Rheumatic Fever) (Strong Recommendation, Moderate Quality of Evidence)
    • Tonsillectomy is Not Recommended Solely to Reduce the Frequency of Streptococcus Pyogenes Pharyngitis (Strong Recommendation, High Quality of Evidence)

References

General

Epidemiology

Etiology

Diagnosis

Treatment