What is the likely diagnosis and recommended management for chronic post‑nasal drip that worsens after meals, improves during fasting, and has a familial predisposition?

Likely Diagnosis: Gastroesophageal Reflux Disease (GERD) Masquerading as Upper Airway Cough Syndrome

The pattern of chronic post-nasal drip that worsens after eating and improves with fasting strongly suggests GERD as the primary driver, though it may coexist with true upper airway pathology. 1, 2

Understanding the Clinical Pattern

Your symptom constellation—post-meal exacerbation and fasting improvement—is highly characteristic of reflux-mediated upper airway irritation rather than primary rhinosinus disease:

• Post-meal worsening indicates either reflux-mediated irritation or increased upper-airway secretion production triggered by gastric acid exposure 1
• Fasting improvement strongly points to GERD, as reduced gastric acid production during fasting periods decreases reflux events 3
• Familial clustering can occur with both GERD (genetic predisposition to lower esophageal sphincter dysfunction) and allergic rhinitis 4, 3

Critical Diagnostic Consideration

• GERD frequently mimics Upper Airway Cough Syndrome (UACS) with upper respiratory symptoms, and up to 75% of patients with GERD-induced cough have no gastrointestinal symptoms 5, 6
• The mechanism involves an esophageal-nasal reflex that increases mucus secretion and nasal congestion, producing symptoms indistinguishable from primary post-nasal drip 2
• Approximately 20% of patients have "silent" post-nasal drip with no obvious nasal symptoms yet still respond to treatment, making the distinction even more challenging 1

Recommended Management Algorithm

Step 1: Empiric GERD Treatment (First-Line)

Initiate high-dose proton pump inhibitor therapy for 8–12 weeks as both diagnostic and therapeutic intervention:

• Omeprazole 20–40 mg twice daily, taken 30 minutes before breakfast and dinner 1, 6
• Improvement in post-nasal drip symptoms may take up to 3 months, so adequate treatment duration is essential 1
• Combine with dietary modifications: avoid fatty/fried foods, chocolate, coffee, carbonated beverages, alcohol, citrus, tomatoes, and spicy foods 3
• Implement eating habit changes: smaller meal volumes, avoid eating within 3 hours of bedtime, maintain regular meal patterns 3

Step 2: Concurrent Upper Airway Treatment

While treating GERD, simultaneously address potential upper airway contribution:

• Intranasal corticosteroid: Fluticasone propionate 100–200 mcg daily (1–2 sprays per nostril) for a minimum 1-month trial 1, 7
• High-volume saline nasal irrigation: 150 mL per nostril twice daily to mechanically remove secretions and improve mucociliary function 1, 7
• Avoid first-generation antihistamine/decongestant combinations initially if GERD is suspected, as these may worsen reflux through anticholinergic effects 1

Step 3: Reassessment at 2–4 Weeks

• If substantial improvement (>50% symptom reduction): Continue PPI therapy for full 8–12 weeks, then attempt gradual taper 6
• If partial improvement: Optimize PPI dosing (ensure twice-daily before meals), reinforce dietary modifications, consider adding H2-blocker at bedtime 1, 4
• If no improvement: Proceed to Step 4

Step 4: Diagnostic Testing (If Refractory)

• 24-hour esophageal pH monitoring to confirm acid reflux and establish temporal correlation with symptoms 5, 6
• Upper endoscopy to assess for erosive esophagitis, Barrett's esophagus, or other structural abnormalities 4
• Sinus CT imaging only if purulent nasal discharge, facial pain/pressure, or fever suggest bacterial sinusitis 1

Step 5: Escalation for Refractory Cases

• Consider adding ipratropium bromide nasal spray (42 mcg per spray, 2 sprays per nostril 4 times daily) for anticholinergic drying effects without systemic cardiovascular side effects 1, 7
• Evaluate for allergic rhinitis with specific IgE testing if the "itching triad" (nose, palate, eyes) or allergic shiners are present 1
• Refer to gastroenterology for consideration of surgical fundoplication if intensive medical therapy fails and pH monitoring confirms severe reflux 5, 6

Common Pitfalls to Avoid

• Do not assume all post-nasal drip is rhinosinus disease—GERD can produce identical symptoms through esophageal-nasal reflex mechanisms 2, 6
• Do not use topical nasal decongestants (oxymetazoline, xylometazoline) for more than 3–5 consecutive days due to rhinitis medicamentosa risk 1, 7
• Do not discontinue partially effective treatments prematurely—UACS, asthma, and GERD often coexist and require simultaneous management 1
• Do not expect rapid response to GERD therapy—improvement may require 8–12 weeks of high-dose PPI treatment 1, 6
• Do not overlook "silent reflux"—absence of heartburn or regurgitation does not exclude GERD as the cause 5, 6

Special Considerations for Your Case

Given the strong temporal relationship with eating and fasting:

• Prioritize GERD treatment over traditional UACS therapy as the initial approach 2, 3
• Maintain a symptom diary tracking post-nasal drip severity in relation to meals, specific foods, and fasting periods to identify triggers 3
• Consider genetic counseling if multiple family members are affected, as both GERD and allergic rhinitis have hereditary components 4, 3
• Monitor for alarm symptoms (dysphagia, odynophagia, weight loss, hematemesis) that would warrant urgent endoscopy 4