Subacute Post-Viral Cough with Upper Airway Cough Syndrome
This is most likely a subacute post-viral cough (10 days duration) with upper airway cough syndrome (UACS), and you should initiate empiric treatment with a first-generation antihistamine/decongestant combination while reassuring the patient that most post-infectious coughs resolve within 3-8 weeks. 1
Clinical Reasoning
The presentation strongly suggests a post-infectious etiology based on:
- Initial viral prodrome: Watery nasal discharge (resolved day 1), mild fever (38°C), and dry cough with sensation of phlegm are classic for viral upper respiratory infection 1
- Timing: 10-day duration places this in the subacute category (3-8 weeks), where post-infectious cough is the leading diagnosis 1
- Symptom evolution: Progressive improvement with residual night throat itchiness and cough attacks strongest at night are characteristic of post-viral airway inflammation and UACS 1
- Physical exam: Swollen non-erythematous pharynx suggests ongoing upper airway inflammation without bacterial superinfection 1
Immediate Management Steps
First-Line Empiric Treatment
Start a first-generation antihistamine/decongestant combination (e.g., diphenhydramine 25-50mg + pseudoephedrine 60mg, three to four times daily) as recommended for UACS 1. This addresses the post-nasal drip component causing throat irritation and nocturnal cough.
Symptomatic Relief
- Dextromethorphan-containing cough suppressants are more effective than the Strepsils (amyloglucosidase) he's been using 1
- Honey and lemon or menthol lozenges for throat irritation 1
- Paracetamol for any residual discomfort 1
Critical Smoking History Consideration
His 6 pack-year smoking history (quit 1 year ago) is relevant but reassuring 1. The majority of ex-smokers experience cough resolution within 4 weeks of cessation, and he's already 1 year out 1. However, this history slightly elevates his baseline risk and warrants closer monitoring.
When to Escalate Workup
Red Flags Requiring Immediate Action
You should obtain a chest X-ray immediately if any of these develop 1, 2:
- Hemoptysis (any amount)
- Progressive dyspnea or breathlessness
- Persistent or recurrent fever
- Constitutional symptoms (weight loss, night sweats)
- Cough persisting beyond 3 weeks total duration
Three-Week Rule
If symptoms persist beyond 3 weeks total (13 more days from now), obtain chest X-ray and consider specialist referral 1. At that point, this transitions from subacute to chronic cough requiring systematic evaluation for:
- UACS (if not already responding to treatment)
- Asthma/cough-variant asthma (bronchoprovocation testing)
- Gastroesophageal reflux disease (GERD)
- Non-asthmatic eosinophilic bronchitis 1
Expected Clinical Course
Most post-infectious coughs resolve within 3-8 weeks without specific intervention 1. With appropriate UACS treatment, you should see improvement within 1-2 weeks. The nocturnal component should improve first as post-nasal drainage decreases 1.
Common Pitfalls to Avoid
- Don't prescribe antibiotics: This is clearly post-viral, and antibiotics won't help even with phlegm sensation 1
- Don't assume chronic bronchitis: He quit smoking a year ago, and chronic bronchitis requires symptoms "on most days for at least 3 months and for at least 2 consecutive years" 1
- Don't delay chest X-ray if red flags emerge: His smoking history, even though remote, means any hemoptysis or constitutional symptoms warrant immediate imaging 2
- Don't overlook GERD: If UACS treatment fails, consider empiric GERD therapy as it can present with isolated throat symptoms and nocturnal cough 1
Documentation and Follow-Up
Schedule follow-up in 2 weeks to assess treatment response. If no improvement, proceed with chest X-ray and consider sequential trials for asthma (inhaled corticosteroids/bronchodilators) and GERD (proton pump inhibitor for 3 months) 1, 3.