What is the definition of recurrent rhinosinusitis?

Definition of Recurrent Rhinosinusitis

Recurrent acute rhinosinusitis (RARS) is defined as four or more episodes per year of acute bacterial rhinosinusitis without signs or symptoms of rhinosinusitis between episodes, with each episode meeting the diagnostic criteria for acute bacterial rhinosinusitis. 1

Diagnostic Criteria

Key Elements of RARS Definition:

1. Frequency requirement:

   • Four or more episodes per year of acute bacterial rhinosinusitis 1
   • Some older guidelines suggested three or more episodes per year 1

2. Complete resolution between episodes:

   • Symptom-free intervals between acute episodes 1
   • No persistent signs or symptoms of rhinosinusitis between episodes 1

3. Each episode must meet criteria for acute bacterial rhinosinusitis:

   • Each episode should present with characteristic symptoms including:
     • Purulent nasal discharge (anterior or posterior)
     • Nasal obstruction/congestion
     • Facial pain/pressure/fullness
     • Possible reduction in sense of smell 1

Distinguishing RARS from Other Forms of Rhinosinusitis

Comparison with Chronic Rhinosinusitis (CRS):

• RARS: Complete resolution between episodes; 4+ discrete episodes yearly
• CRS: Persistent symptoms for 12+ weeks without resolution 1

Comparison with Isolated Acute Bacterial Rhinosinusitis (ABRS):

• RARS: Pattern of recurrence (4+ episodes yearly)
• ABRS: Single, isolated episode without established pattern of recurrence 1

Clinical Significance

RARS represents a distinct clinical entity with:

• Similar symptom burden to chronic rhinosinusitis 1
• Higher antibiotic utilization compared to CRS 1
• Potential impact on quality of life comparable to CRS 2

Diagnostic Approach

Confirming the Diagnosis:

1. Documentation of episodes:

   • Ideally, examination during an acute episode to corroborate diagnosis 1
   • Examination of middle meatus for purulence in the decongested state may strongly suggest ABRS 1

2. Objective confirmation:

   • While confirming a true bacterial episode is desirable, it is not essential for diagnosis 1
   • Endoscopically guided culture during an episode may be helpful 1

Caution in Diagnosis:

• Studies have shown that patients with self-diagnosed "recurrent sinus infections" rarely have abnormal CT findings during acute exacerbations 3
• Only about 4% of patients with suspected RARS actually demonstrate objective evidence of sinus disease on acute imaging 3

Management Considerations

Most otolaryngologists wait until patients have experienced 4-5 episodes before considering procedural interventions such as balloon sinuplasty or formal sinus surgery 4.

Common Pitfalls in Diagnosis

1. Misdiagnosis of other conditions as RARS:

   • Rhinitis (47%)
   • Headache/migraine (37%)
   • Facial pain of other origins (12.5%) 3

2. Overdiagnosis based on symptoms alone:

   • Symptom-based criteria have high sensitivity but low specificity 1
   • Objective confirmation during an acute episode is valuable

3. Inconsistent diagnostic criteria:

   • Diagnostic definitions have evolved over time, making comparison between studies difficult 5
   • Current definition is based primarily on expert opinion rather than high-level evidence 5

Remember that appropriate diagnosis of RARS is essential to avoid unnecessary antibiotic use and surgical interventions in patients whose symptoms may be due to other conditions.