Postnasal Drip Syndrome

Postnasal drip syndrome (upper airway cough syndrome) is the sensation of secretions draining from the nose into the throat, with throat clearing and chronic cough. It is a symptom complex produced by allergic rhinitis, non allergic rhinitis, chronic sinusitis, and sometimes laryngopharyngeal reflux.

• It is among the commonest causes of chronic cough in adults.
• Cough is thought to follow stimulation of cough receptors in the pharynx and larynx.
• Triggers are allergens, cold air, smoke, perfumes, spicy food and pregnancy.

Constant need to clear the throat, a sense of mucus at the back of the throat, cough worse when lying down or on waking, hoarseness, nasal blockage and sneezing.

• Examination may show cobblestone pharyngeal mucosa, mucus at the posterior pharynx, pale boggy turbinates or purulent discharge.
• Differential diagnosis: asthma, gastro oesophageal reflux, ACE inhibitor cough, pertussis, tuberculosis, bronchiectasis, lung cancer, heart failure, habit cough.
• Complications: chronic cough with sleep disruption, voice strain, sinusitis, rib or muscle pain, urinary incontinence from cough.

Clinical, supported by response to treatment.

• Anterior rhinoscopy and nasopharyngeal endoscopy.
• Chest radiograph in all patients with chronic cough, and sputum tests for tuberculosis where indicated.
• Spirometry and allergy testing as relevant; CT of the sinuses if sinusitis is suspected.

Treat the underlying nasal or sinus condition.

• Supportive: saline nasal irrigation twice daily, allergen and smoke avoidance, elevate the head of the bed, adequate hydration, avoid late meals and caffeine.
• Pharmacological: chlorphenamine 4 mg every 6 hours (adults) or at night for sedation; intranasal mometasone 200 micrograms twice daily or fluticasone 2 sprays per nostril daily for allergic rhinitis; azelastine nasal spray 1 spray per nostril twice daily; ipratropium 0.06 percent nasal spray 2 sprays three times daily for watery drip; omeprazole 20 mg twice daily for 8 weeks if reflux features are present; amoxicillin clavulanate 625 mg three times daily for 7 days if bacterial sinusitis.
• Procedures: sinus surgery or turbinate reduction for refractory structural disease.
• Special groups: pregnancy, saline and fluticasone, avoid decongestant tablets; children, saline, steroid spray and non sedating antihistamine; hypertension, avoid pseudoephedrine; older adults, avoid sedating antihistamines.
• Red flags: haemoptysis, weight loss, night sweats, dysphagia, smoker with hoarseness, cough beyond 8 weeks despite treatment, clubbing.
• Follow-up: review at 2 to 4 weeks; investigate for asthma, reflux and chest disease if no response.