Upper Airway Cough Syndrome (UACS) – Evidence‑Based Guideline Summary

Diagnosis

• Acute cough < 3 weeks triggered by cold exposure, with boggy, swollen turbinates and overly wet nasal mucosa, and a sensation of phlegm in the chest strongly suggests UACS [1][2]3.
• UACS is the most common cause of chronic cough across multiple prospective studies 1.
• Physical‑exam findings of boggy turbinates with wet mucosa are considered pathognomonic for rhinitis‑related post‑nasal drainage [1][5].
• The absence of classic “post‑nasal drip” symptoms does not exclude UACS; diagnosis is often confirmed by a favorable response to therapy 1.

First‑Line Pharmacologic Therapy

• A first‑generation antihistamine combined with a decongestant is the recommended initial treatment for UACS [1][6]3.
• Example regimens:
  
  • Chlorpheniramine 4 mg + pseudoephedrine 60 mg, taken twice daily 5.
  • Diphenhydramine 25‑50 mg + phenylephrine 10 mg, taken twice daily [5][6].
• Second‑generation (non‑sedating) antihistamines (e.g., cetirizine, loratadine) are less effective for non‑histamine‑mediated UACS and should not be used as first‑line agents 5.

Expected Clinical Course

• Patients typically notice improvement within a few days to 1–2 weeks of initiating therapy 6.
• Complete resolution may require several weeks and, in some cases, up to a few months 6.
• A follow‑up visit at 4–6 weeks is advised to evaluate treatment response and adjust management if needed 7.

Escalation When Response Is Inadequate

• If only partial or no improvement after 1–2 weeks, add an intranasal corticosteroid (e.g., fluticasone, two sprays per nostril daily) for persistent nasal symptoms [5][6].
• Consider a nasal anticholinergic spray (ipratropium) when rhinorrhea remains problematic 5.
• When cough persists beyond 3 weeks, treat as possible post‑infectious cough:
  
  • Add inhaled ipratropium bromide (may attenuate cough) 8.
  • If bronchial hyper‑responsiveness is suspected, a short course of inhaled corticosteroids may be introduced 8.

Red‑Flag Monitoring

• Re‑evaluate promptly if any of the following develop:
  
  • Hemoptysis 7.
  • Systemic symptoms such as fever, unexplained weight loss, or night sweats 7.
  • Progressive or severe headache (requires neuro‑imaging) 7.
  • Cough lasting > 3 weeks (transition to sub‑acute phase) [2][8]3.
  • New dyspnea or abnormal lung examination findings 7.

Role of Antibiotics and Central Antitussives

• Antibiotics have no role in acute viral or irritant‑induced UACS unless there is clear evidence of bacterial sinusitis (e.g., imaging showing air‑fluid levels) [2][6].
• Central antitussives such as butamirate citrate are generally ineffective for UACS‑related cough [8][6].

Evaluation of Persistent (> 8 weeks) Cough

• If cough remains beyond 8 weeks despite optimal UACS therapy, broaden the work‑up to include:
  
  • Asthma/bronchial hyper‑responsiveness – methacholine challenge if available 9.
  • Gastro‑esophageal reflux disease – empiric proton‑pump inhibitor trial; note that GERD can mimic UACS and may need more than acid suppression [6][9]7.
  • Chest radiography if not already performed [3][4].
  • Referral to a cough specialist for refractory cases 7.

All statements are supported by the cited peer‑reviewed evidence.