Description

• Acute sinusitis is a symptomatic inflammation of ≥1 paranasal sinuses of <4 weeks duration resulting from impaired drainage and retained secretions accompanied by obstruction, facial pain/pressure/fullness, or both. Because rhinitis and sinusitis usually coexist, “rhinosinusitis” is the preferred term.
• Disease is subacute when symptomatic for 4 to 12 weeks, recurrent acute when ≥4 annual episodes without persistent symptoms in between, and chronic when symptomatic for >12 weeks.
• Uncomplicated rhinosinusitis has no extension of inflammation beyond paranasal sinuses and nasal cavity.

Epidemiology

• Affects 1 in 8 adults (>30 million people in the United States yearly diagnosed with rhinosinusitis)
• Acute bacterial rhinosinusitis remains the fifth leading reason for prescribing antibiotics.
• Viral cause in 90–98% of cases with 0.5–2% having a bacterial superinfection

Incidence
Incidence is highest in early fall through early spring (related to the incidence of viral upper respiratory infection [URI]). Adults have 2 to 3 viral URIs per year; 90% of colds are accompanied by viral rhinosinusitis. It is the fifth most common diagnosis during family physician visits.

Etiology and Pathophysiology

• Important features
  • Inflammation and edema of the sinus mucosa lead to obstruction of the sinus ostia causing impaired mucociliary clearance and stagnation of secretions that become hospitable to bacterial growth.
• Neutrophil influx and release of cytokines damage mucosal surfaces.
• Viral: majority of cases (rhinovirus; influenza A and B; parainfluenza; respiratory syncytial, adeno-, corona-, and enteroviruses)
• Bacterial (complicates 0.5–2% of viral cases)
  • More likely if symptoms worsen within 5 to 6 days after initial improvement
  • No improvement within 10 days of symptom onset
  • >3 to 4 days of fever >102°F and facial pain and purulent nasal discharge
  • Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the most common bacterial pathogens.
  • Overdiagnosis may lead to overuse of and increasing resistance to antibiotics.
  • Methicillin-resistant Staphylococcus aureus present in 0–15.9% of patients
• Fungal: seen in immunocompromised hosts (uncontrolled diabetes, neutropenia, use of corticosteroids) or as a nosocomial infection; most common etiology is aspergillus.

Risk Factors

• Viral URI
• Allergic rhinitis
• Asthma
• Cigarette smoking
• Dental infections and procedures
• Anatomic variations
  • Tonsillar and adenoid hypertrophy
  • Turbinate hypertrophy, nasal polyps
  • Cleft palate
  • Septal deviations
• Immunodeficiency (e.g., HIV)
• Cystic fibrosis (CF)
• Prolonged supine positioning (i.e., ICU patients)

General Prevention

Hand washing, vaccinations, avoiding symptomatic individuals, avoid smoking, and exposure to secondhand smoke.