Description

• Acute sinusitis is a symptomatic inflammation of ≥1 paranasal sinuses of <4 weeks’ duration resulting from impaired drainage and retained secretions. Because rhinitis and sinusitis usually coexist, “rhinosinusitis” is the preferred term.
• Disease is subacute when symptomatic for 4–12 weeks and chronic when symptomatic for >12 weeks.
• System(s) affected: Head/Eyes/Ears/Nose/Throat (HEENT); Pulmonary

Epidemiology

• Affects 31 million individuals in the US each year, with an estimated annual cost of $5.8 billion
• Diagnosis of acute bacterial rhinosinusitis remains the 5th leading reason for prescribing antibiotics.
• 2% of viral rhinosinusitis episodes have a bacterial superinfection.

Incidence
Incidence highest in early fall through early spring (related to incidence of viral upper respiratory infection [URI]). Adults have 2–3 viral URIs per year; 90% of these colds are accompanied by viral rhinosinusitis.

Risk Factors

• Viral URI
• Allergic rhinitis
• Asthma
• Cigarette smoking
• Dental infections and procedures
• Anatomic variations:
  • Tonsillar and adenoid hypertrophy
  • Turbinate hypertrophy, nasal polyps
  • Deviated septum
  • Cleft palate
• Immunodeficiency (e.g., HIV)
• Cystic fibrosis

Genetics
No known genetic pattern

General Prevention

Hand washing to prevent transmission of viral infection

Pathophysiology

• Important features:
  • Inflammation and edema of the sinus mucosa
  • Obstruction of the sinus ostia
  • Impaired mucociliary clearance
• Secretions that are not cleared become hospitable to bacterial growth.
• Inflammatory response (neutrophil influx and release of cytokines) damages mucosal surfaces.

Etiology

• Viral: Vast majority of cases (rhinovirus, influenza A and B; parainfluenza virus; respiratory syncytial; adeno-, corona-, and enteroviruses)
• Bacterial (complicates 0.2–2% of viral cases):
  • More likely if symptoms worsen after 5–7 days or do not improve >10 days
  • S. pneumoniae, H. influenzae, and M. catarrhalis are the most common bacterial pathogens.
  • Often overdiagnosed, which leads to overuse of and increasing resistance to antibiotics
• Fungal: Seen in immunocompromised hosts (uncontrolled diabetes, neutropenia, use of corticosteroids) or as a nosocomial infection