What is the treatment for Upper Airway Cough Syndrome (UACS)?

Treatment for Upper Airway Cough Syndrome (UACS)

Start immediately with a first-generation antihistamine/decongestant combination as first-line therapy for UACS, specifically dexbrompheniramine 6 mg plus pseudoephedrine 120 mg (sustained-release) twice daily, or azatadine 1 mg plus pseudoephedrine 120 mg (sustained-release) twice daily. 1, 2

First-Line Treatment Algorithm

Initial Empiric Therapy

• Begin with first-generation antihistamine/decongestant combinations as the most effective evidence-based treatment, regardless of whether the underlying cause is allergic or non-allergic rhinitis 1, 2
• Specific proven combinations include:
  • Dexbrompheniramine 6 mg + pseudoephedrine 120 mg (sustained-release) twice daily 1, 2
  • Azatadine 1 mg + pseudoephedrine 120 mg (sustained-release) twice daily 1, 2
  • Brompheniramine 12 mg + pseudoephedrine 120 mg (sustained-release) twice daily 1, 2
• Alternative first-generation antihistamines (if combination products unavailable): chlorpheniramine 4 mg four times daily, diphenhydramine 25-50 mg four times daily, or hydroxyzine 25 mg four times daily 2

Why First-Generation Antihistamines Work

• First-generation antihistamines are effective primarily through their anticholinergic properties, not their antihistamine effects 1, 2
• The anticholinergic effect reduces secretions and limits inflammatory mediators that trigger the cough reflex 2
• This explains why newer non-sedating antihistamines (cetirizine, loratadine, fexofenadine) are ineffective for UACS—they lack the necessary anticholinergic activity 1, 2

Dosing Strategy to Minimize Side Effects

• Start with once-daily dosing at bedtime for a few days before increasing to twice-daily therapy to minimize sedation 1, 2
• Most patients will see improvement within days to 2 weeks of initiating therapy 1
• Common side effects include dry mouth, transient dizziness, and sedation 1
• Monitor for more serious side effects: insomnia, urinary retention, jitteriness, tachycardia, worsening hypertension, and increased intraocular pressure in glaucoma patients 1

Treatment Based on Underlying Cause

For Allergic Rhinitis

• Add intranasal corticosteroids immediately alongside the antihistamine/decongestant combination when allergic rhinitis is confirmed 1, 3
• Fluticasone 100-200 mcg daily for a 1-month trial 1, 3
• Alternative first-line agents for allergic rhinitis include nasal cromolyn or oral leukotriene inhibitors (montelukast 10 mg daily) 1, 3
• For moderate-to-severe allergic rhinitis, the combination of intranasal fluticasone plus intranasal azelastine provides superior symptom reduction (40% relative improvement over monotherapy) 3

For Non-Allergic Rhinitis

• First-generation antihistamine/decongestant combination remains first-line therapy 1
• Intranasal corticosteroids may be added but are not as well-studied for non-allergic rhinitis 3
• Ipratropium bromide nasal spray (42 mcg per spray, 2 sprays per nostril 4 times daily) is an alternative for patients who don't respond to antihistamine/decongestant combinations or have contraindications 1

For Postviral Upper Respiratory Infection

• First-generation antihistamine/decongestant combinations have proven efficacy in both acute and chronic cough 1
• Do not use newer-generation antihistamines with or without pseudoephedrine—they are ineffective for acute cough in postviral upper respiratory infection 1

Sequential Evaluation if No Response After 2 Weeks

Step 1: Add Intranasal Corticosteroids

• If no improvement after 1-2 weeks with antihistamine/decongestant alone, add intranasal corticosteroids (fluticasone 100-200 mcg daily) for a 1-month trial 1
• Consider adding ipratropium bromide nasal spray for additional anticholinergic drying effects 1

Step 2: Obtain Sinus Imaging

• If persistent nasal symptoms despite topical therapy, obtain sinus imaging (radiographs or CT) 1
• Air-fluid levels indicate acute bacterial sinusitis requiring antibiotics 1
• Mucosal thickening <8mm is usually sterile and does not require antibiotics 1

Step 3: Evaluate for Other Causes

• If symptoms persist despite adequate upper airway treatment for 2 weeks, proceed with sequential evaluation for asthma/non-asthmatic eosinophilic bronchitis and GERD 1
• UACS, asthma, and GERD together account for approximately 90% of chronic cough cases 1, 4
• Maintain all partially effective treatments rather than discontinuing them prematurely, as multiple causes often coexist 1

Treatment for GERD (if suspected)

• Initiate empiric therapy with omeprazole 20-40 mg twice daily before meals for at least 8 weeks plus dietary modifications 1
• Improvement in cough from GERD treatment may take up to 3 months 1
• GERD frequently mimics UACS with upper respiratory symptoms 5, 1

Adjunctive Therapies

Nasal Saline Irrigation

• High-volume saline nasal irrigation (150 mL) improves outcomes through mechanical removal of mucus, enhanced ciliary activity, and disruption of inflammatory mediators 1
• More effective than saline spray because irrigation better expels secretions 1
• Longer treatment duration (mean 7.5 months) shows better results than shorter courses 1

Symptomatic Cough Relief

• Consider dextromethorphan as an over-the-counter cough suppressant for symptomatic relief 1
• The sedating effect of first-generation antihistamines is actually advantageous for nocturnal cough 2

Critical Pitfalls to Avoid

Silent UACS

• Approximately 20% of patients have "silent" postnasal drip with no obvious symptoms yet still respond to treatment 5, 1
• The absence of typical findings (postnasal drainage, cobblestoning, throat clearing) does not rule out UACS 5, 1
• Always give an empiric trial of first-generation antihistamine/decongestant therapy before looking for less common causes of chronic cough 5

Medication Selection Errors

• Never use newer-generation antihistamines (cetirizine, loratadine, fexofenadine) for UACS—they are ineffective 1, 2
• Never use topical nasal decongestants (oxymetazoline, xylometazoline) for more than 3-5 consecutive days due to risk of rhinitis medicamentosa 1
• Avoid first-generation antihistamines in patients with glaucoma, symptomatic prostatic hypertrophy, urinary retention, or cognitive impairment 2

Premature Antibiotic Use

• Do not diagnose bacterial sinusitis during the first week of symptoms, even with purulent nasal discharge or sinus imaging abnormalities—these findings are indistinguishable from viral rhinosinusitis 1
• Consider antibiotics only if symptoms persist beyond 10 days without improvement, or if there is "double sickening" (initial improvement followed by worsening) 1

Monitoring Requirements

• Monitor blood pressure after initiating decongestant therapy, as decongestants can worsen hypertension and cause tachycardia 1
• Monitor intraocular pressure in glaucoma patients taking first-generation antihistamines 1

Maintenance Therapy

Duration of Treatment

• Complete resolution of UACS may take several weeks to a few months 1
• For chronic rhinitis conditions, longer treatment courses may be necessary 1
• Continue intranasal corticosteroids for 3 months after cough resolution to maintain symptom control and prevent recurrence 3