What are the diagnostic steps and treatments for postnasal drip syndrome and allergic rhinitis?

Diagnosis and Management of Postnasal Drip Syndrome and Allergic Rhinitis

The diagnosis of postnasal drip syndrome (now termed Upper Airway Cough Syndrome) and allergic rhinitis requires a combination of specific symptom assessment, physical examination findings, and in some cases, objective testing, followed by targeted treatment with intranasal corticosteroids as first-line therapy for moderate to severe cases. 1

Diagnostic Approach

Postnasal Drip Syndrome/Upper Airway Cough Syndrome (UACS)

• Key Diagnostic Features:

  • Patient-reported sensation of secretions dripping down the throat
  • Frequent throat clearing
  • Presence of mucoid or mucopurulent secretions in nasopharynx/oropharynx
  • Cobblestoning of posterior pharyngeal mucosa 2

• Important Note: There is no objective test for postnasal drip, and the term "Upper Airway Cough Syndrome" (UACS) is now preferred over "postnasal drip syndrome" as it better reflects the pathophysiology 2

• Diagnostic Algorithm:

  1. Evaluate for characteristic symptoms (throat clearing, sensation of drainage)
  2. Perform nasopharyngeal examination to identify secretions or cobblestoning
  3. Consider underlying causes (listed below)
  4. Empiric treatment serves as both diagnostic and therapeutic tool 2

Allergic Rhinitis

• Key Diagnostic Features:

  • Nasal congestion, rhinorrhea, sneezing, nasal/ocular itching
  • Symptoms after exposure to known allergens
  • Seasonal pattern (for seasonal allergic rhinitis)
  • Pale, boggy nasal mucosa on examination 2

• Diagnostic Algorithm:

  1. Assess symptom pattern (seasonal vs. perennial)
  2. Evaluate for pruritus and sneezing (more common in allergic than nonallergic rhinitis)
  3. Note age of onset (allergic rhinitis typically begins before age 20)
  4. Examine nasal mucosa for pallor, edema, or hyperemia
  5. Consider specific IgE testing if diagnosis uncertain 2, 1

Differential Diagnosis

Causes of Postnasal Drip/UACS:

• Allergic rhinitis (28%)
• Chronic sinusitis or nasal polyps (31%)
• Chronic rhinitis (22%)
• Adenoid hypertrophy (16%)
• Chronic nasopharyngitis (3%) 3
• Gastroesophageal reflux disease (may mimic UACS) 2

Types of Rhinitis:

• Allergic rhinitis
• Perennial nonallergic rhinitis
• Postinfectious rhinitis
• Rhinitis medicamentosa (from topical decongestant overuse)
• Vasomotor rhinitis
• Occupational rhinitis
• Rhinitis of pregnancy 2

Treatment Approach

First-Line Therapy:

• Intranasal corticosteroids are the most effective first-line treatment for both conditions 1, 4
  • Options include fluticasone propionate, triamcinolone, budesonide, mometasone
  • Dosing: Adults may start with 200 mcg once daily (two 50-mcg sprays in each nostril)
  • Alternative regimen: 100 mcg twice daily (one 50-mcg spray in each nostril twice daily)
  • Pediatric patients (≥4 years): Start with 100 mcg daily 4

Additional Therapies:

• For Allergic Rhinitis:

  • Second-generation oral antihistamines (less sedating than first-generation)
  • Intranasal antihistamines
  • Leukotriene receptor antagonists (e.g., montelukast)
  • Combination therapy for enhanced efficacy 2, 1

• For Postnasal Drip/UACS:

  • Antihistamine/decongestant combinations (for allergic causes)
  • Saline nasal irrigation
  • Treatment of underlying cause (sinusitis, allergic rhinitis, etc.) 2
  • Nasal flushing with herbal liquids (for chronic rhinitis) 3

Special Considerations

• Diagnostic Pitfalls:

  • "Silent" postnasal drip: Approximately 20% of patients with UACS are unaware of PND 2
  • Non-allergic rhinitis may be mistaken for allergic rhinitis 1
  • Serious conditions (e.g., nasopharyngeal tumors) can present with similar symptoms 5

• Treatment Pitfalls:

  • Rhinitis medicamentosa from overuse of topical decongestants (limit use to <3 days) 2
  • First-generation antihistamines cause sedation and cognitive impairment 1
  • Improper intranasal corticosteroid technique reduces efficacy 1

• When to Refer:

  • Persistent symptoms despite optimal therapy
  • Unilateral symptoms (may suggest structural problem)
  • Warning signs of malignancy
  • Presence of nasal polyps 2, 5

Follow-up and Monitoring

• Schedule follow-up within 2-4 weeks for moderate to severe symptoms
• Assess treatment response and quality of life
• Consider treatment modifications if symptoms persist:
  • Increase dose of intranasal corticosteroid
  • Add second medication
  • Investigate other potential causes 1

By following this systematic approach to diagnosis and treatment, most patients with postnasal drip syndrome/UACS and allergic rhinitis can achieve significant symptom relief and improved quality of life.