Postnasal drip

Postnasal drip is the sensation of mucus running from the nose or sinuses into the throat, often with throat clearing, cough or a sensation of throat lump. It is a symptom, not a diagnosis.

Mechanisms. Increased nasal secretion (rhinitis, sinusitis), abnormal mucus (thickened, impaired clearance), reduced clearance, and heightened sensory awareness of normal secretions.

Classification. Acute (under 4 weeks, usually viral), subacute, and chronic (over 8 weeks). By cause: rhinogenic, sinogenic, laryngopharyngeal reflux related, medication related, and idiopathic.

Key distinctions. Cough from postnasal drip is a diagnosis of exclusion. Persistent unilateral symptoms with blood stained discharge need nasal endoscopy.

History. Duration, character of mucus (clear, thick, purulent, blood stained), throat clearing, cough (especially lying down), hoarseness, sneezing, itch, nasal obstruction, facial pain, smell loss, heartburn, regurgitation, dysphagia, asthma, atopy, smoking, occupational exposures, and weight loss.

Drug history. ACE inhibitors (cough), topical decongestants, antihypertensives causing rhinitis (beta blockers, alpha blockers), phosphodiesterase inhibitors, oral contraceptives, and aspirin or NSAIDs in polyp disease.

Examination. Anterior rhinoscopy and nasal endoscopy (mucosa, discharge, polyps, turbinates), oropharynx (cobblestoning, mucus strands), larynx (laryngopharyngeal reflux signs: arytenoid erythema, oedema), neck nodes, chest, and ears.

Red flags

• Unilateral blood stained discharge, mass or ulcer
• Persistent hoarseness, dysphagia or neck mass
• Weight loss, haemoptysis or smoking with cough
• Facial swelling, orbital signs or visual change
• Fever with facial pain and swelling

Special groups. Children: adenoiditis, allergic rhinitis, foreign body. Pregnancy: rhinitis of pregnancy. Older adults: dysphagia, aspiration and drug related causes.

Nasal and sinus

• Allergic and non-allergic rhinitis, vasomotor rhinitis
• Acute and chronic rhinosinusitis, nasal polyps
• Rhinitis medicamentosa, drug induced rhinitis
• Adenoiditis, adenoidal hypertrophy
• Septal deviation, turbinate hypertrophy

Pharyngeal and laryngeal

• Laryngopharyngeal reflux, gastro-oesophageal reflux disease
• Chronic pharyngitis, tonsil crypts and tonsilloliths
• Zenker diverticulum, oesophageal dysmotility
• Laryngeal and pharyngeal cancer, nasopharyngeal carcinoma

Other

• Dehydration, dry environment, smoking and irritants
• Cystic fibrosis, primary ciliary dyskinesia, immunodeficiency
• Anxiety and heightened awareness

Reasoning. Examine for nasal and sinus disease and for reflux features. Start empirical treatment for the most likely cause, and investigate when there are red flags or no response.

First line. Anterior rhinoscopy, nasal endoscopy and oropharyngeal examination. Peak flow or spirometry for coexisting asthma.

Targeted tests. CT sinuses without contrast for chronic rhinosinusitis after medical treatment. Skin prick tests or specific IgE for suspected allergy. Laryngoscopy (flexible) for hoarseness or throat symptoms. Barium swallow or endoscopy for suspected pharyngeal pouch or oesophageal disease. Biopsy and MRI for any mass. Sweat chloride and immunoglobulins in children with recurrent infection.

Limitations. The sensation correlates poorly with objective findings. Laryngeal signs of reflux are non-specific.

Allergic and non-allergic rhinitis. Mometasone 50 micrograms, 2 sprays to each nostril once daily (maximum 200 micrograms daily), or fluticasone propionate 50 micrograms, 2 sprays to each nostril once daily. Loratadine 10 mg orally once daily or cetirizine 10 mg orally once daily (5 mg in renal impairment). Intranasal azelastine 0.1 percent, 1 spray to each nostril twice daily. Saline irrigation, 2 to 3 times daily. Ipratropium bromide 0.03 percent nasal spray, 2 sprays to each nostril two or three times daily for watery secretions.

Acute bacterial rhinosinusitis. Amoxicillin 500 mg orally three times daily for 5 days (maximum 3 g daily); penicillin allergy: doxycycline 200 mg orally on day 1 then 100 mg daily for 5 days (avoid in pregnancy and under 12 years).

Chronic rhinosinusitis. Saline irrigation, intranasal corticosteroid, prednisolone 30 mg orally daily for 7 to 14 days for polyps (check glucose and blood pressure), and ENT referral for surgery after 3 months of medical treatment.

Laryngopharyngeal reflux. Omeprazole 20 to 40 mg orally once daily before breakfast for 8 to 12 weeks (review, then step down), with alginate after meals, weight reduction, avoidance of late meals, alcohol and smoking, and raising the head of the bed. Lack of response at 12 weeks needs ENT review and consideration of other causes.

Rhinitis medicamentosa. Stop the decongestant, with intranasal corticosteroid and saline irrigation.

Drug induced cough. ACE inhibitor: switch to an angiotensin receptor blocker (losartan 50 mg orally once daily); cough settles within 1 to 4 weeks of stopping.

General measures. Hydration, humidification, stop smoking, and avoidance of triggers. Throat clearing is avoided, because it causes irritation.

Neoplastic disease. Urgent ENT and head and neck oncology referral with biopsy.

Monitoring. Review at 4 to 6 weeks. Reassess after 3 months in chronic cases.

Referral and escalation. ENT within 2 weeks for unilateral blood stained discharge, mass, persistent hoarseness or dysphagia. ENT or allergy review for refractory symptoms after 3 months.

Admission criteria. Complicated sinusitis with orbital or intracranial signs, or airway compromise.

Discharge and safety netting. Return for facial swelling, eye swelling or visual change, fever with severe headache, bloody discharge, hoarseness persisting over 3 weeks, swallowing difficulty or weight loss.