Treatment for Upper Airway Cough Syndrome (UACS)
Start immediately with a first-generation antihistamine combined with a decongestant (e.g., dexbrompheniramine 6 mg + pseudoephedrine 120 mg sustained-release twice daily) as the primary treatment for UACS. 1, 2
First-Line Empiric Therapy
The cornerstone of UACS treatment is a first-generation antihistamine/decongestant combination, which serves both as therapy and as a diagnostic tool. 1, 3
Recommended regimens include:
- Dexbrompheniramine 6 mg + pseudoephedrine 120 mg (sustained-release) twice daily 1
- Azatadine 1 mg + pseudoephedrine 120 mg (sustained-release) twice daily 1
- Brompheniramine 12 mg twice daily 1
- Chlorpheniramine 4 mg four times daily 1
Critical mechanism: First-generation antihistamines work primarily through their anticholinergic properties, NOT their antihistamine effects, which is why they are effective for UACS. 1, 2
Second-generation antihistamines (loratadine, fexofenadine, cetirizine) are completely ineffective for UACS because they lack anticholinergic activity and should never be used. 1, 2
Dosing Strategy to Minimize Side Effects
To reduce sedation from first-generation antihistamines, start with once-daily dosing at bedtime for a few days, then increase to twice-daily therapy. 2
Common side effects include dry mouth and transient dizziness, while more serious effects include insomnia, urinary retention, jitteriness, tachycardia, worsening hypertension, and increased intraocular pressure in glaucoma patients. 2
Expected Timeline and Response Assessment
Most patients will improve within days to 2 weeks of initiating therapy. 2 Complete resolution may take several weeks to a few months. 2
A positive response (cough improves or resolves within 1-2 weeks) confirms the diagnosis of UACS—continue the regimen for the underlying upper airway condition. 1
Adding Intranasal Corticosteroids
For Allergic Rhinitis
If allergic rhinitis is the identified cause, add intranasal corticosteroids immediately alongside the antihistamine/decongestant combination. 4
- Fluticasone propionate 100-200 mcg daily (1-2 sprays per nostril) 2, 4
- Continue for a 1-month trial initially 2
- Intranasal corticosteroids are the most effective monotherapy for allergic rhinitis and act synergistically with antihistamines 4
For Non-Allergic Rhinitis or Chronic Sinusitis
If no improvement after 1-2 weeks with the antihistamine/decongestant combination alone, add intranasal corticosteroids. 2
Once cough resolves, continue intranasal corticosteroids for 3 months to maintain symptom control and prevent recurrence. 4
Alternative or Adjunctive Therapies
Ipratropium bromide nasal spray (42 mcg per spray, 2 sprays per nostril 4 times daily) provides anticholinergic drying effects without systemic cardiovascular side effects and is an alternative for patients with contraindications to decongestants. 2
High-volume saline nasal irrigation (150 mL) improves outcomes through mechanical removal of mucus, enhanced ciliary activity, and disruption of inflammatory mediators—more effective than saline spray. 2
When Initial Treatment Fails
If no response after 2 weeks of appropriate antihistamine/decongestant therapy, proceed to sinus imaging (CT scan). 1
Chronic sinusitis may produce a relatively non-productive or "silent" cough, lacking typical acute sinusitis signs. 1 Air-fluid levels on imaging indicate acute bacterial sinusitis requiring antibiotics. 2
Evaluating for Coexisting Conditions
UACS, asthma, and gastroesophageal reflux disease (GERD) together account for roughly 90% of chronic cough etiologies, and multiple conditions frequently coexist. 1, 3
If symptoms persist despite adequate upper airway treatment for 2 weeks, sequentially evaluate for:
Asthma/cough-variant asthma: Perform methacholine challenge testing if spirometry is normal, or consider empiric inhaled corticosteroids plus bronchodilators. 1
GERD: Initiate empiric proton pump inhibitor therapy (omeprazole 20-40 mg twice daily before meals) for at least 8 weeks plus dietary modifications. 1, 2 Improvement in cough from GERD treatment may take up to 3 months. 2
Maintain all partially effective treatments rather than discontinuing them prematurely, as multiple causes often coexist. 2
Critical Pitfalls to Avoid
Do not rely on cough characteristics (productive vs. non-productive, timing, or quality) to differentiate UACS from other causes—these features are unreliable. 1
Do not assume that lack of upper airway symptoms excludes UACS—approximately 20% of patients are unaware of postnasal drainage ("silent" UACS) yet still respond to treatment. 1, 2
Do not use topical nasal decongestants (oxymetazoline, xylometazoline) for more than 3-5 consecutive days due to the risk of rhinitis medicamentosa (rebound congestion). 2
Monitor blood pressure after initiating decongestant therapy, as decongestants can worsen hypertension and cause tachycardia. 2
Do not evaluate UACS in isolation—always assess for possible coexisting asthma or GERD, especially when response to therapy is partial. 1