Postnasal Drip

Postnasal drip is the sensation of mucus running from the back of the nose into the throat, causing frequent throat clearing, swallowing, throat irritation and sometimes cough. When it provokes chronic cough it is called upper airway cough syndrome. Mucus is produced normally at about 1 to 1.5 litres a day and swallowed unnoticed, so the symptom arises from increased or thicker mucus, poor clearance, or a more sensitive pharynx and larynx.

• Rhinitis: allergic (seasonal, perennial), non-allergic (vasomotor), infectious, atrophic, hormonal (pregnancy, hypothyroidism), decongestant overuse, occupational and irritant, gustatory, and drug induced (ACE inhibitors, alpha blockers, beta blockers, oral contraceptives, phosphodiesterase inhibitors).
• Rhinosinusitis: acute and chronic, with or without polyps.
• Anatomical: deviated septum, enlarged adenoids, nasal polyps, concha bullosa, foreign body, tumour.
• Laryngopharyngeal and gastro oesophageal reflux; cystic fibrosis, primary ciliary dyskinesia and immune deficiency; dry air, smoking and irritants; swallowing disorders such as pharyngeal pouch.
• Complications: chronic cough, hoarseness, sleep disturbance, halitosis, recurrent sinusitis.

• Mucus felt at the back of the nose or throat, constant throat clearing, hawking, frequent swallowing, a tickle or lump in the throat, cough worse lying down or in the morning, hoarseness, bad breath, nasal blockage, sneezing and itchy eyes if allergic.
• Examination: cobblestone appearance of the posterior pharyngeal wall with mucus streaks, swollen or pale turbinates, polyps, septal deviation, purulent discharge.
• Red flags: purulent discharge with facial pain and fever beyond 10 days or worsening after initial improvement; unilateral symptoms, bleeding or foul smell (tumour, foreign body); weight loss, dysphagia, hoarseness lasting over 3 weeks; haemoptysis; recurrent chest infections, bronchiectasis or poor growth (cystic fibrosis, ciliary dyskinesia); immunodeficiency; periorbital swelling or visual change; neck mass; smoker over 40.

• Clinical, by history and examination; response to treatment of the upper airway supports it.
• Anterior rhinoscopy or nasal endoscopy and laryngoscopy for persistent or atypical cases.
• Allergy testing (specific IgE or skin prick) for suspected allergic rhinitis. Total IgE, eosinophils if relevant.
• Imaging: CT of the sinuses for chronic rhinosinusitis, suspected complications, polyps or failed treatment. Plain sinus X-rays are not helpful.
• Chest X-ray and spirometry for chronic cough; reflux assessment if heartburn, hoarseness or throat clearing without rhinitis.
• Differentials: gastro oesophageal and laryngopharyngeal reflux, asthma, cough variant asthma, habitual throat clearing, vocal cord dysfunction, ACE inhibitor cough, chronic bronchitis, laryngeal pathology, Eustachian tube dysfunction.

• General: saline nasal irrigation (isotonic or hypertonic) once or twice daily; adequate hydration; humidification; avoid smoke and allergens; elevate the head of the bed; stop drugs that cause rhinitis.
• Allergic rhinitis:
  • Intranasal corticosteroids: mometasone 50 micrograms per spray, 2 sprays per nostril once daily; or fluticasone propionate 50 micrograms per spray, 2 sprays per nostril once daily; or budesonide 64 micrograms per spray, 2 sprays per nostril once daily. Benefit builds over days to 2 weeks.
  • Second generation antihistamines: cetirizine 10 mg or loratadine 10 mg or fexofenadine 120 to 180 mg once daily.
  • Azelastine 0.1 percent nasal spray, 1 to 2 sprays per nostril twice daily; combined azelastine and fluticasone spray, 1 spray per nostril twice daily.
  • Montelukast 10 mg at night as an add on if asthma coexists.
  • Allergen immunotherapy for severe persistent disease (specialist).
• Non-allergic and vasomotor rhinitis: ipratropium bromide 0.06 percent nasal spray, 2 sprays per nostril three to four times daily; intranasal corticosteroid or azelastine.
• Night time symptoms: chlorphenamine 4 mg orally at night (sedating; avoid in older adults, glaucoma, urinary retention). Avoid oral decongestants in hypertension and prostatic enlargement. Do not use topical decongestants beyond 3 days.
• Acute bacterial rhinosinusitis (symptoms over 10 days without improvement, or severe, or double worsening): amoxicillin 500 mg orally three times daily for 5 to 7 days; alternatives co-amoxiclav 625 mg three times daily or doxycycline 100 mg twice daily for 5 to 7 days (penicillin allergy). Add or use an intranasal steroid.
• Chronic rhinosinusitis: long term saline irrigation, intranasal steroid, short oral prednisolone 30 mg daily for 5 to 7 days for polyps, ENT referral for surgery.
• Reflux related: omeprazole 20 mg once daily 30 minutes before breakfast for 8 weeks; lifestyle changes (avoid late meals, raise bed head, reduce alcohol and caffeine, lose weight).
• Habitual throat clearing: speech therapy, sipping water, voluntary suppression of clearing.
• Review at 2 to 4 weeks. Refer to ENT for red flags, polyps, structural obstruction, chronic sinusitis or failure of treatment, and to a respiratory physician for chronic cough not explained by the upper airway.