What are the clinical presentations and management approaches for pharyngitis?

Pharyngitis: Clinical Presentation and Management

Pharyngitis is primarily caused by viral infections in most cases, but Group A Streptococcal (GAS) pharyngitis requires antibiotic treatment to prevent complications such as acute rheumatic fever and glomerulonephritis. 1, 2

Clinical Presentation

Viral Pharyngitis

• Cough
• Rhinorrhea (runny nose)
• Hoarseness
• Oral ulcers
• Conjunctivitis (in some adenoviral infections)
• Generalized lymphadenopathy 1, 2, 3

Bacterial Pharyngitis (GAS)

• Sudden onset of throat pain
• Fever
• Headache
• Bilateral tender cervical lymphadenopathy
• Tonsillopharyngeal erythema with or without exudates
• Absence of cough and rhinorrhea
• Nausea, vomiting, and abdominal pain (especially in children) 1, 2, 4

Diagnosis

Centor Criteria for GAS Pharyngitis Assessment

1. Tonsillar exudates
2. Tender anterior cervical lymph nodes
3. Lack of cough
4. Fever 2

Diagnostic Testing

• Testing is NOT recommended when clinical features strongly suggest viral etiology (cough, rhinorrhea, hoarseness, oral ulcers) 1, 2
• Testing is NOT indicated for children <3 years old (acute rheumatic fever is rare in this age group) 1
• Testing IS recommended for patients with signs and symptoms suggestive of GAS pharyngitis 1

Testing Methods

1. Rapid Antigen Detection Test (RADT):

   • High specificity but lower sensitivity
   • Results available in minutes
   • Positive results do not require backup culture
   • Negative results in children and adolescents should be confirmed with throat culture 1, 2

2. Throat Culture:

   • Gold standard for diagnosis
   • Results take 24-48 hours
   • Higher sensitivity than RADT 2

Management

Antibiotic Treatment for GAS Pharyngitis

First-line treatment (non-allergic patients):

• Penicillin V:
  • Children: 250 mg 2-3 times daily for 10 days
  • Adults: 250 mg 4 times daily or 500 mg twice daily for 10 days 1, 2
• Amoxicillin:
  • 50 mg/kg once daily (max 1000 mg) or
  • 25 mg/kg twice daily (max 500 mg per dose) for 10 days 1, 2
• Benzathine penicillin G (intramuscular):
  • <27 kg: 600,000 U
  • ≥27 kg: 1,200,000 U (single dose) 1

For penicillin-allergic patients:

• First-generation cephalosporins (if not anaphylactically sensitive):
  • Cephalexin: 20 mg/kg twice daily (max 500 mg per dose) for 10 days
  • Cefadroxil: 30 mg/kg once daily (max 1 g) for 10 days 1
• Clindamycin: 7 mg/kg 3 times daily (max 300 mg per dose) for 10 days 1
• Azithromycin: 12 mg/kg once daily (max 500 mg) for 5 days 1, 5
• Clarithromycin: 7.5 mg/kg twice daily (max 250 mg per dose) for 10 days 1

Adjunctive Therapy

• Analgesics/antipyretics: Acetaminophen or NSAIDs for moderate to severe symptoms or high fever
• Avoid aspirin in children
• Corticosteroids are not recommended 1, 2
• Symptomatic relief: Cold liquids, ice chips, gargling with cold water, throat lozenges every two hours 2

Special Considerations

Recurrent Pharyngitis

• Consider that patients may be experiencing multiple episodes of GAS pharyngitis at close intervals
• Be alert to the possibility of chronic pharyngeal GAS carrier experiencing repeated viral infections 1

Chronic Carriers

• GAS carriers generally do not require antimicrobial therapy
• Carriers are unlikely to spread GAS pharyngitis to close contacts
• Carriers are at little or no risk for developing complications 1, 6

Tonsillectomy

• Not recommended solely to reduce the frequency of GAS pharyngitis 1
• May be considered for patients with severe recurrent episodes:
  • ≥7 episodes in the past year, OR
  • ≥5 episodes per year for 2 consecutive years, OR
  • ≥3 episodes per year for 3 consecutive years 2, 6

Complications of Untreated GAS Pharyngitis

• Acute rheumatic fever
• Post-streptococcal glomerulonephritis
• Deep space abscesses
• Toxic shock syndrome
• Pulmonary-renal syndrome (rare but potentially fatal) 7, 6

Prevention

• Proper identification and adequate antibiotic treatment of GAS pharyngitis
• Continuous antimicrobial prophylaxis for patients with history of rheumatic fever
• Hand hygiene and infection control measures 2