Upper Airway Cough Syndrome

Upper airway cough syndrome is cough resulting from irritation of the cough receptors in the upper airway by secretions draining from the nose and sinuses (postnasal drip), or from inflammation of the nasal, pharyngeal and laryngeal mucosa. It replaced the older term "postnasal drip syndrome", because cough can arise without perceptible drip.

• It is the commonest cause of chronic cough, responsible for about 20 to 40% of cases, either alone or in combination with asthma and reflux. It is also a frequent cause of subacute cough.
• Underlying conditions:
  • Allergic rhinitis (seasonal and perennial).
  • Non-allergic rhinitis (vasomotor, drug induced, hormonal, gustatory, and irritant).
  • Acute viral rhinitis and the common cold, with postnasal drip for up to 3 weeks.
  • Acute and chronic rhinosinusitis (bacterial, fungal), nasal polyps and structural problems (a deviated septum, concha bullosa, adenoid hypertrophy in children).
  • Medicines: ACE inhibitors, beta blockers, phosphodiesterase-5 inhibitors, topical decongestant overuse (rhinitis medicamentosa), oral contraceptives.
• The mechanism is thought to be direct stimulation of cough receptors in the larynx and pharynx, and a heightened cough reflex from nasal inflammation, through the vagal and trigeminal pathways.
• Prevalence of allergic rhinitis is 10 to 30% of adults and up to 40% of children. Chronic rhinosinusitis affects about 5 to 12% of adults.
• Risk factors: atopy, asthma, family history, smoking, environmental pollution, occupational dust, cold air, reflux, and anatomical nasal obstruction.

• A chronic or subacute cough, usually wet or throat clearing, worse on lying down at night and on waking in the morning, and with a frequent need to clear the throat.
• A sensation of mucus dripping into the back of the throat, nasal congestion, nasal discharge (clear in allergy, thick in infection), sneezing, itchy nose and eyes, loss of smell, facial pressure or headache, halitosis and a hoarse voice.
• Examination: a "cobblestone" appearance of the posterior pharyngeal wall (lymphoid hyperplasia) and mucus in the oropharynx, pale boggy nasal turbinates (allergy), erythematous swollen mucosa, mucopurulent discharge, nasal polyps (pale, grape like), a deviated septum, and allergic shiners (dark circles under the eyes), a transverse nasal crease and mouth breathing in children.
• Differential diagnosis: asthma, eosinophilic bronchitis, gastro oesophageal reflux, ACE inhibitor cough, post-infectious cough, vocal cord dysfunction, laryngeal disorders, chronic bronchitis, sleep apnoea, and habit cough.
• Absence of symptoms does not exclude the diagnosis, because about 20% of patients with this syndrome have no nasal symptoms ("silent" postnasal drip).
• Red flags: unilateral nasal obstruction or bleeding (tumour), facial swelling, eye signs (proptosis, double vision, reduced vision), severe headache with fever and neck stiffness, a persistent unilateral foul discharge, hoarseness for more than 3 weeks, a neck mass, and weight loss.
• Complications: chronic rhinosinusitis, nasal polyps, otitis media with effusion, sleep disturbance, orbital cellulitis and intracranial infection (rare), and reduced quality of life.

• Clinical diagnosis. A positive response to treatment of the upper airway condition is the diagnostic test, with a 2 to 4 week course of therapy.
• Examine the nose with a headlight and speculum, the oropharynx and the ears, and, where available, perform nasal endoscopy to identify polyps, purulent discharge, and structural problems.
• Allergy testing (skin prick tests or specific IgE) for suspected allergic rhinitis when symptoms are persistent and the trigger affects management. Total IgE and eosinophil count are non-specific.
• Imaging: CT of the sinuses is the investigation of choice for chronic rhinosinusitis (symptoms for more than 12 weeks) when the diagnosis is uncertain or before surgery. Plain sinus X-rays are not recommended. Use CT or MRI urgently for orbital or intracranial signs.
• Rule out other causes with a chest X-ray and spirometry in all patients with chronic cough, and test for asthma (exhaled nitric oxide, bronchial challenge), and consider reflux.
• Review medicines, including ACE inhibitors and topical nasal decongestants.

• Remove triggers: allergen avoidance (house dust mite covers, hot washing of bedding at 60 C, pollen avoidance with closed windows and shower after exposure, and treating pets), stop smoking, and avoid irritants.
• Saline nasal irrigation: isotonic or hypertonic saline (0.9 to 2.7%), 120 to 240 mL per nostril using a squeeze bottle or neti pot, once or twice daily, with boiled and cooled or distilled water. This reduces symptoms in allergic rhinitis and chronic rhinosinusitis.
• Allergic rhinitis:
  • Intranasal corticosteroid is the most effective treatment: fluticasone propionate 50 micrograms per spray, 2 sprays into each nostril once daily (200 micrograms daily), reduced to 1 spray per nostril for maintenance, or mometasone furoate 50 micrograms per spray, 2 sprays into each nostril once daily, or fluticasone furoate 27.5 micrograms per spray, 2 sprays into each nostril once daily. Direct the spray away from the septum, and expect full effect in 1 to 2 weeks. Adverse effects: nose bleeding, dryness and, rarely, septal perforation.
  • Intranasal antihistamine: azelastine 137 micrograms per spray, 1 to 2 sprays into each nostril twice daily, which acts within 15 minutes (adults and children over 12 years), or a combined azelastine and fluticasone nasal spray, 1 spray into each nostril twice daily, for moderate to severe disease. Bitter taste and drowsiness may occur.
  • Oral second generation antihistamine: cetirizine 10 mg once daily (child 2 to 5 years 2.5 mg 12 hourly, 6 to 11 years 5 mg 12 hourly or 10 mg daily), loratadine 10 mg once daily (child 2 to 5 years 5 mg daily), or fexofenadine 120 to 180 mg once daily (12 years and over).
  • Montelukast 10 mg orally once daily at night (child 2 to 5 years 4 mg, 6 to 14 years 5 mg), as an alternative or an add on, particularly with asthma. Monitor for mood and sleep changes.
  • Allergen immunotherapy (subcutaneous or sublingual) for 3 to 5 years, in specialist care, for severe, persistent allergic disease with proven sensitisation.
• Non-allergic and postinfectious rhinitis (postnasal drip):
  • First generation antihistamine with a decongestant: chlorphenamine 4 mg orally every 4 to 6 hours (maximum 24 mg per day), or an extended release 12 mg dose at night, for 1 to 2 weeks. Warn about drowsiness, dry mouth, urinary retention, and confusion in older adults, and avoid in glaucoma and prostatic enlargement.
  • Ipratropium bromide nasal spray 0.03% (21 micrograms per spray), 2 sprays per nostril 2 to 3 times a day, for watery rhinorrhoea, or 0.06% (42 micrograms per spray), 2 sprays 3 to 4 times a day.
  • Pseudoephedrine 60 mg orally every 6 hours (maximum 240 mg per day) for 3 to 5 days for nasal congestion. Avoid in hypertension, coronary disease, hyperthyroidism, glaucoma, prostatic enlargement and pregnancy in the first trimester.
  • Oxymetazoline 0.05% nasal spray, 2 to 3 sprays into each nostril every 12 hours, for no more than 3 to 5 days, because longer use causes rebound congestion (rhinitis medicamentosa). Treat rhinitis medicamentosa by stopping the decongestant and giving intranasal steroid for 2 to 4 weeks, with a short course of oral prednisolone 20 to 30 mg for 5 days in severe cases.
• Acute bacterial rhinosinusitis (symptoms for more than 10 days without improvement, or severe features such as fever above 39 C with purulent discharge and facial pain for 3 to 4 days, or worsening after initial improvement):
  • Amoxicillin 500 mg orally 8 hourly for 5 to 7 days (or 1 g 8 hourly in high resistance settings), with intranasal steroids and saline.
  • Penicillin allergy: doxycycline 200 mg on day 1, then 100 mg daily for 5 to 7 days (children over 8 years), or clarithromycin 500 mg 12 hourly for 5 days.
  • Treatment failure after 48 to 72 hours: amoxicillin clavulanate 625 mg orally 8 hourly for 5 to 7 days.
  • Refer urgently for orbital swelling, double vision, severe frontal headache with swelling, meningism, or reduced consciousness.
• Chronic rhinosinusitis: saline irrigation, intranasal corticosteroid (continued for at least 8 to 12 weeks), and a short course of oral prednisolone 30 mg daily for 5 to 7 days for polyps. Prolonged low dose macrolide (clarithromycin 250 mg once daily for 12 weeks, or azithromycin 250 mg 3 times a week) in non-eosinophilic disease, in specialist care. Refer to ENT for polyps, structural problems, or failure of 8 to 12 weeks of medical treatment, and for functional endoscopic sinus surgery.
• Children: nasal saline, intranasal fluticasone furoate 27.5 micrograms, 1 spray per nostril once daily (2 to 11 years), or mometasone 50 micrograms 1 spray per nostril once daily (3 to 11 years), cetirizine 2.5 to 5 mg once or twice daily by age, or loratadine 5 mg daily (2 to 5 years) or 10 mg daily (6 years and over). Avoid oral decongestants under 6 years and first generation antihistamines under 2 years. Assess adenoid hypertrophy in children with chronic nasal obstruction and snoring.
• Special groups:
  • Pregnancy: saline irrigation, intranasal budesonide 64 micrograms per spray, 2 sprays into each nostril once daily, or intranasal cromoglicate 2% (one spray 4 times daily). Loratadine 10 mg once daily and cetirizine 10 mg once daily are acceptable. Avoid pseudoephedrine in the first trimester and use oxymetazoline for 3 days at most. For sinusitis, amoxicillin is suitable.
  • Elderly: avoid first generation antihistamines (anticholinergic effects, confusion, falls), and use caution with decongestants in hypertension or heart disease.
  • Hypertension and heart disease: avoid oral decongestants, and use saline and intranasal steroids.
  • Renal impairment: halve the dose of cetirizine to 5 mg daily when creatinine clearance is below 30 mL/min.
  • Glaucoma and prostatic enlargement: avoid first generation antihistamines and anticholinergic nasal sprays at high doses.
• Follow up: review at 2 to 4 weeks. A good response confirms the diagnosis, and treatment is continued for 4 to 8 weeks before a stepwise reduction. If cough persists, assess for asthma, reflux and other causes. Refer to ENT or allergy for treatment failure at 4 to 8 weeks, suspected polyps, unilateral disease, bleeding, or complicated sinusitis.