What is the most likely diagnosis and appropriate outpatient management for an adult with a one‑week history of nasal congestion, dry nocturnal cough, chest tightness at bedtime, fatigue, low appetite, occasional headache, and no fever or dyspnea?

Most Likely Diagnosis and Outpatient Management

This clinical presentation is most consistent with post-viral upper airway cough syndrome (UACS) with post-infectious cough, and the appropriate management is symptomatic treatment with a first-generation antihistamine/decongestant combination plus intranasal corticosteroids, avoiding antibiotics entirely.

Clinical Diagnosis

Post-Viral Upper Airway Cough Syndrome with Post-Infectious Cough

This one-week presentation fits the classic pattern of viral upper respiratory infection transitioning to post-infectious cough:

• Nasal congestion and dry nocturnal cough for one week indicate ongoing upper airway inflammation following viral infection 1
• Chest tightness only at bedtime (not persisting overnight) suggests upper airway secretions draining when supine rather than true lower airway disease 2
• Marked fatigue, low appetite, occasional headaches are typical constitutional symptoms of viral URI that can persist into the post-infectious phase 3, 1
• Occasional nighttime chills without fever represent residual inflammatory response rather than bacterial infection 3
• No fever, no dyspnea, no focal chest findings effectively exclude pneumonia and bacterial sinusitis 3, 4

The absence of fever, purulent sputum, crackles, or focal chest signs rules out pneumonia, which would require chest radiography 3, 4. The dry cough and lack of wheezing make acute bronchitis with bronchospasm less likely 4.

Evidence-Based Management Algorithm

First-Line Treatment (Initiate Immediately)

1. First-Generation Antihistamine/Decongestant Combination

• Prescribe chlorpheniramine 4 mg with sustained-release pseudoephedrine 120 mg twice daily for 1-2 weeks 2
• This combination has the strongest evidence for UACS and post-viral cough, superior to newer non-sedating antihistamines 2
• To minimize sedation: start with once-daily dosing at bedtime for 2-3 days, then advance to twice daily 2
• Expected response time: improvement within days to 1-2 weeks 2

2. Intranasal Corticosteroid

• Add fluticasone propionate nasal spray 100-200 mcg (1-2 sprays) per nostril once daily for a minimum 1-month trial 2, 5
• Intranasal corticosteroids are the most effective monotherapy for both allergic and non-allergic rhinitis-related UACS 2, 5
• Maximum benefit may take several days to weeks 5

3. Supportive Measures

• Recommend honey and lemon as initial symptomatic relief through central cough reflex modulation 1
• Guaifenesin 200-400 mg every 4 hours (up to 6 times daily) to help thin secretions 1
• High-volume saline nasal irrigation (150 mL per nostril) to mechanically remove secretions and improve mucociliary clearance 2
• Adequate hydration, rest, and sleeping with head of bed elevated 1

Second-Line Treatment (If No Improvement After 1-2 Weeks)

Inhaled Ipratropium Bromide

• Prescribe ipratropium bromide inhaler 2-3 puffs (17-34 mcg per puff) four times daily 1
• This has the strongest evidence for attenuating post-infectious cough 1
• Expected response: 1-2 weeks 1

What NOT to Do

Antibiotics Are Explicitly Contraindicated

• Do NOT prescribe amoxicillin, azithromycin, or any antibiotic 1, 4
• This is a viral illness, not bacterial infection 1, 4
• Antibiotics provide zero benefit, contribute to antimicrobial resistance, and cause adverse effects including allergic reactions and C. difficile infection 1, 4
• The absence of fever, purulent sputum, and focal chest findings confirms this is not bacterial pneumonia or sinusitis 3, 4

Oral Corticosteroids Are Not Indicated

• Do NOT prescribe prednisone at this stage 1
• Oral steroids are reserved only for severe post-infectious cough paroxysms that significantly impair quality of life, and only after failure of ipratropium and inhaled corticosteroids 1

Avoid Topical Nasal Decongestants

• Never use oxymetazoline or xylometazoline nasal sprays for more than 3-5 days due to risk of rhinitis medicamentosa (rebound congestion) 2

Timeline Expectations and Follow-Up

Expected Course:

• Acute viral URI symptoms typically peak at days 3-6 and begin improving by day 7-10 3
• Post-infectious cough is defined as cough persisting 3-8 weeks after initial infection 1
• With appropriate treatment, improvement should occur within 10-14 days 1

Reassess at 2-3 Weeks:

• If cough persists despite adequate upper airway treatment for 2 weeks, proceed with sequential evaluation for asthma/cough-variant asthma and GERD 2
• If cough extends beyond 8 weeks, reclassify as chronic cough and systematically evaluate for UACS, asthma, and GERD 1

Red Flags Requiring Immediate Re-evaluation:

• Development of fever (suggests bacterial superinfection) 3, 1
• Hemoptysis (requires chest radiograph and specialist referral) 3
• Worsening dyspnea or chest pain 3
• Symptoms that worsen after initial improvement ("double sickening" suggests bacterial sinusitis) 2

Common Pitfalls to Avoid

1. Prescribing Antibiotics for Viral Illness

The single most common error is prescribing antibiotics for post-viral symptoms 1, 4. Green or colored nasal discharge does NOT indicate bacterial infection—most viral URIs produce colored phlegm 1.

2. Using Newer-Generation Antihistamines

Cetirizine, loratadine, and fexofenadine are ineffective for non-allergic UACS and should not be used 2. First-generation antihistamines with anticholinergic properties are required 2.

3. Failing to Consider "Silent" UACS

Approximately 20% of patients have no obvious nasal symptoms yet still respond to UACS-directed treatment 2. The absence of visible post-nasal drainage does not exclude the diagnosis 2.

4. Monitoring Decongestant Side Effects

Monitor blood pressure after initiating pseudoephedrine, as it can worsen hypertension and cause tachycardia 2. Other side effects include insomnia, jitteriness, and urinary retention 2.

5. Premature Discontinuation of Partially Effective Therapy

If one treatment provides partial improvement, continue it while adding the next intervention rather than stopping and switching 2. UACS, asthma, and GERD frequently coexist and require simultaneous treatment 2.