How do I diagnose a deviated septum?

Diagnosing a Deviated Nasal Septum

The gold standard for diagnosing a deviated nasal septum is physical examination including anterior rhinoscopy and nasal endoscopy, as CT scans correlate poorly with physical exam findings and may underestimate the degree of nasal obstruction. 1

Physical Examination Techniques

Anterior Rhinoscopy

• Use a nasal speculum to visualize the anterior portion of the nasal cavity
• Assess for:
  • Visible deviation of the septum from midline
  • Narrowing of one nasal passage
  • Septal spurs or crests
  • Mucosal inflammation or congestion

Nasal Endoscopy

• Essential for thorough evaluation, especially for posterior deviations
• Procedure:
  1. Apply topical anesthetic and decongestant before the procedure 2
  2. Observe the effect of decongestant clinically before proceeding 2
  3. Use a rigid endoscope (pediatric scope may be needed for severe deviations) 2
  4. Systematically examine the nasal cavity, paying special attention to:
     • Degree of septal deviation
     • Effect on nasal airflow
     • Associated mucosal changes
     • Impact on middle meatus and ostiomeatal complex

Systematic Evaluation Approach

Divide the nose into horizontal thirds for comprehensive assessment 2:

1. Upper third (bony pyramid)
2. Middle third (dorsal septum and upper lateral cartilages)
3. Lower third (alar cartilages, caudal septum, and alar base)

For each third, document:

• Direction of deviation (right or left)
• Severity of deviation
• Associated asymmetries in shape, width, or length

Diagnostic Pitfalls to Avoid

1. Over-reliance on CT imaging: CT has limited correlation with physical examination findings and may underestimate the degree of nasal obstruction, particularly at the internal nasal valve 2, 1

2. Inadequate decongestant use: Failure to properly decongest the nasal mucosa can lead to misdiagnosis of septal deviation when turbinate hypertrophy is the actual cause 2

3. Missing posterior deviations: Anterior rhinoscopy alone may miss significant posterior septal deviations that require endoscopic examination 2

4. Confusing asymmetry with deviation: Acknowledge the difference between asymmetry (differences in shape) and true deviation (displacement from midline) 2

5. Overlooking the nasal valve: The internal nasal valve is a critical area for airflow that may be compromised by even minor septal deviations 1

Role of Imaging

• CT scans: Not recommended solely for evaluating septal deviation 2

  • Should be reserved for:
    • Evaluating associated sinusitis
    • Surgical planning when indicated
    • Ruling out other pathologies

• Radiography: Limited utility due to overlapping osseous structures 2

Clinical Correlation

Always correlate physical findings with patient symptoms:

• Nasal obstruction (unilateral or bilateral)
• Difficulty breathing through the nose
• Recurrent sinusitis
• Epistaxis
• Headaches
• Sleep disturbances

Special Considerations

• Adolescent patients: Higher risk of re-deviation (21.2% vs 7.1% in adults) if surgical correction is performed 3

• Comorbidities: Assess for associated conditions that may exacerbate symptoms:

  • Allergic rhinitis
  • Chronic rhinosinusitis
  • Sleep-disordered breathing 4

By following this systematic approach to diagnosis, clinicians can accurately identify septal deviations and determine their clinical significance, which is essential for appropriate management decisions.