Sinusitis

Descriptive text is not available for this imageBASICS

DESCRIPTION

  • Sinusitis is inflammation of the mucous membranes lining the paranasal sinuses.
  • The term is most commonly used to describe bacterial rhinosinusitis, which is a clinical diagnosis made by the presence of upper respiratory tract symptoms that have not improved in 10 days or have worsened after 5 to 7 days. Sinusitis may be classified in a number of ways.
    • Classification based on duration of symptoms:
      • Acute: persistent nasal and sinus symptoms for 10 to 30 days; worsening or new onset of nasal discharge, daytime cough, or fever after initial improvement; or concurrent high fever and purulent nasal discharge for the first 3 to 4 days of an acute upper respiratory infection (URI)
      • Subacute: clinical symptoms for 30 to 90 days
      • Chronic: symptoms lasting >90 days
      • Recurrent: acute sinusitis with 10 days of complete resolution between episodes; three episodes in 6 months or 4 episodes in 1 year
    • Classification by severity of illness:
      • Persistent acute: >10 to 14 days but <30 days; nasal discharge and/or daytime cough
      • Severe acute: temperature of ≥39°C (102.2°F) with concurrent purulent nasal discharge for ≥3 days and/or facial pain, headache, or periorbital edema

ETIOLOGY

  • Viral pathogens (e.g., rhinovirus, parainfluenza virus) are often recovered in respiratory isolates.
  • Most illnesses of short duration (<7 days) are thought to be due to viral infection and therefore should not be treated with antibiotics.
  • Chronic sinusitis is often secondary to allergic rhinitis, cystic fibrosis, environmental pollutants, or gastroesophageal reflux. Variants include noneosinophilic and eosinophilic variants, allergic fungal sinusitis, primary immunodeficiency, and disorders of mucociliary clearance.
  • Most common bacterial pathogens:
    • Haemophilus influenzae, nontypeable (with Streptococcus pneumoniae, make up 30% of cases)
    • S. pneumoniae
    • Moraxella catarrhalis (10% of cases)
  • Other bacterial pathogens:
    • Group A streptococci
    • Group C streptococci
    • Peptostreptococci
    • Other Moraxella species
    • Streptococcus viridans
    • Eikenella corrodens
    • Staphylococcus aureus (infrequent but significant pathogen in orbital and intracranial complications)
    • Pseudomonas aeruginosa (in patients with cystic fibrosis)
    • Anaerobic organisms
  • Polymicrobial
  • Fungal pathogen: Aspergillus

GENERAL PREVENTION

  • Avoid allergen exposure and treat allergies if present.
  • Improve mucociliary clearance by increasing ambient humidity with a humidifier.

PATHOPHYSIOLOGY

  • Normal sinus function depends on patency of paranasal sinus ostia, function of the ciliary apparatus, and secretion quality.
  • Secretions accumulate due to ostial obstruction, reduction in ciliary function, and overproduction.
  • Viral URIs and/or allergic rhinitis often precede(s) acute bacterial sinusitis.
  • Acute bacterial sinusitis is a complication of 5–10% of URIs.

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