Pharyngitis

last authored: Oct 2009, Dave LaPierre
last reviewed:

 

 

Introduction

Acute pharyngitis is an inflammation of the oropharynx.

 

 

 

The Case of...

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Causes and Risk Factors

Pharyngitis can be caused by a wide range of infectious organisms, most of which are self-limited with no long-term effects. Viruses are the most common cause of pharyngitis, and infections occur year round. These include:

viruses:

group A β-hemolytic Streptococcus (GAS) is the most common bacterial cause, responsible for 5-15% of adult cases and up to 50% of pediatric cases. It is most prevalent in people 5-17 years old, with infections most frequently occurring in winter months. GAS is less common in children <3, in whom viral causes are most common. Other bacteria include:

fungal: Candida

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Pathophysiology

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Signs, Symptoms, and Diagnosis

  • viral
  • bacterial
  • sore throat score
  • lab investigations

viral

Viral disease can lead to pharyngitis, conjunctivitis, rhnnorhea, hoarseness, and cough.

Non-specific flu-like symptoms such as fever, malaise, and myalgia are present.

This often mimics bacterial infection.

Coxasckie virus and herpes simplex virus can cause mucosal or cutaneous ulcers, while EBV can cause substantial systemic symptoms.

bacterial

Symptoms of bacterial infection include:

  • sore throat
  • absence of cough
  • fever
  • malaise
  • headache
  • abdominal pain
  • tonsillar/pharyngeal erythema/exudate (also seen with adenovirus, EBV, diphtheria)
  • swollen/tender anterior cervical nodes
  • soft palate petechiae (asleo seen with EBV)

sore throat score

The McIsaac Critera assogns score based on GAS likelihood. (Hot LACE)

One point each

  • history of fever >38
  • swollen/tender anterior Lymph nodes
  • Age 3-14 = 1 point
  • cough absent
  • tonsillar Exudate
  • age 15-44 = 0 points
  • age >45 = -1 point

 

0-1: 2-7% chance of Strep: NO culture or antibiotic

2-3:8-34% chance of Strep: culture all; treat only if culture is positive

4: 41-61% chance of Strep; culture all; treat on clinical grounds

 

 

 

Lab Investigations

 

Gold standard is throat culture.

 

The rapid test for Strep antigen has a high specificity (95%) but low sensitivity (50-90%).

  • If positive, treat patient
  • If negative, take culture and begin antibiotics as indicated

antibiotic testing

Peripheral blood smear, heterophile antibody test (latex agglutination/monospot) tests for EBV

 

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Differential Diagnosis

Other potential conditions include:

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Treatments

Viral pharyngitis

Do NOT use antibiotics.

Treat with acetaminophen/NSAIDs for fever, muscle aches, and decongestants.

 

 

Strep Throat

There is no increase in rheumatic fever with 48 hour delay, and no decrease in glomerulonephritis with antiobiotic treatment.

Ten-day antibiotic course:

Follow-up recommended for patients with history or family history of rheumatic fever, suspected strep carrier.

 

Infectious mononucleosis

Do NOT use antibiotics; ampicillin will cause a rash.

Mono is a self-limiting disease. Rest during the acute phase is helpful.

If acute airway obstruction, give corticosteroids and consult ENT.

Give acetaminophen/NSAIDs for fever, sore throat, malaise

Avoid heavy physical activity and contact sports for at least one month, or until splenomegaly resolves, because of risk of splenic rupture.

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Consequences and Course

While most viral and bacterial infections are self-limiting, complications of GAS infection include scarlet fever, rheumatic fever, glomerulonephritis, supporative complication, meningitis, and impetigo.

Suppurative complications can include otitis media, sinusitis, cervical adenitis, pneumonia, and mastoiditis.

Direct invasion can lead to peritonsillar abscess.

Bloodstream spread can lead to osteomyelitis, septic arthritis, or meningitis. Acute glomerulonephritis can also occur.

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Resources and References

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Topic Development

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