What is the most likely diagnosis and appropriate next steps for a 32‑year‑old female outpatient who presents 4 days after onset of dry cough worsened by fluids, thick white nasal discharge, congestion, heavy squeezing headache, one fever episode of 38 °C, sensation of phlegm stuck in throat, normal vital signs and physical examination, a history of recurrent cough episodes, and self‑medication with Lagundi, Bactidol mouthwash (chlorhexidine), phenylpropanolamine HCl + chlorpheniramine maleate (Symdex D), and vitamin C and zinc?

Most Likely Diagnosis: Acute Viral Rhinosinusitis with Post-Infectious Cough

This 32-year-old woman has acute viral rhinosinusitis transitioning to post-infectious cough, and antibiotics are explicitly contraindicated. 1, 2

Clinical Reasoning

Your patient's 4-day timeline with initial dry cough, thick white nasal discharge, congestion, and a single fever episode of 38°C that resolved with paracetamol fits the classic pattern of acute viral rhinosinusitis (AVRS). 3 The European Position Paper on Rhinosinusitis defines AVRS as symptoms lasting <10 days with nasal blockage/congestion or nasal discharge plus facial pain/pressure. 3 Her current sensation of "phlegm stuck in throat and chest" after 4 days represents the expected evolution toward post-infectious cough, which typically emerges as the acute viral phase resolves. 1, 2

Key diagnostic features supporting viral (not bacterial) etiology:

• Symptom duration only 4 days (bacterial rhinosinusitis requires ≥10 days of persistent symptoms, worsening after initial improvement, or severe symptoms in first 3-4 days) 3
• Single fever episode that resolved spontaneously 1
• White (not purulent green/yellow) nasal discharge 3
• Normal vital signs and physical examination 1
• No focal lung findings, crackles, or signs of pneumonia 1

Immediate Next Steps

1. Reassurance and Education

Explain that her symptoms are expected to worsen in the first few days, then gradually improve over 1-2 weeks without antibiotics. 1 The sensation of phlegm is part of normal viral recovery and does not indicate bacterial infection. 2

2. Continue Symptomatic Management

Continue her current regimen of phenylpropanolamine HCl + chlorpheniramine maleate (Symdex D) for nasal congestion, but limit nasal decongestant sprays to 3-5 days maximum to avoid rebound congestion. 1

Add guaifenesin 200-400 mg every 4 hours (up to 6 times daily) to help fluidify mucus and bronchial secretions. 1, 2 This is FDA-approved, safe, cost-effective, and addresses her complaint of phlegm stuck in throat. 1

Recommend honey and lemon, adequate hydration, warm facial packs, steamy showers, and sleeping with head of bed elevated. 2

3. Explicitly Avoid Antibiotics

Do not prescribe amoxicillin, azithromycin, or any antibiotic. 1, 2 The American College of Chest Physicians explicitly states that antibiotics have no role in acute viral bronchitis or post-infectious cough, provide no benefits, contribute to antimicrobial resistance, and cause adverse effects including allergic reactions and C. difficile infection. 1, 2

When to Escalate Treatment

If Cough Persists Beyond 1-2 Weeks

Prescribe inhaled ipratropium bromide 2-3 puffs four times daily if cough persists beyond 1-2 weeks and compromises quality of life. 1, 2 This has the strongest evidence for attenuating post-infectious cough, with clinical response expected within 1-2 weeks. 1, 2

If Cough Persists Beyond 3 Weeks

Add inhaled corticosteroids (fluticasone 220 mcg or budesonide 360 mcg twice daily) if cough persists ≥3 weeks and significantly affects quality of life despite ipratropium. 2 Allow up to 8 weeks for full response. 2

Reserve oral prednisone 30-40 mg daily for 5-10 days only for severe paroxysms that significantly impair quality of life, and only after ruling out upper airway cough syndrome, asthma, and GERD. 2

Red Flags Requiring Immediate Re-evaluation

Instruct the patient to return immediately if: 1, 2

• Fever develops or recurs
• Symptoms worsen after initial improvement (suggests bacterial superinfection)
• Hemoptysis occurs
• Dyspnea or tachypnea develops
• Symptoms persist beyond 10 days without constant improvement (consider bacterial rhinosinusitis) 3
• Cough persists beyond 8 weeks (reclassify as chronic cough and systematically evaluate for upper airway cough syndrome, asthma, and GERD) 2

Special Consideration: Pertussis

Consider pertussis if cough develops paroxysmal character with post-tussive vomiting or inspiratory "whoop" sound, especially given her history of recurring cough episodes. 4 If suspected, obtain nasopharyngeal swab for culture and start empiric macrolide therapy (azithromycin or clarithromycin) without waiting for results. 4

What NOT to Do

• Do not order chest X-ray in this young, healthy patient with normal vital signs and clear lung examination 1
• Do not prescribe antibiotics for uncomplicated viral rhinosinusitis or post-infectious cough 1, 2
• Do not jump to prednisone for mild symptoms 1, 2
• Do not use nasal decongestant sprays >3-5 days due to rebound congestion risk 1

Expected Timeline

Cough from uncomplicated viral infection is worst in the first days and should gradually improve over 1-2 weeks. 1 If symptoms worsen after initial improvement or persist beyond 2-3 weeks without constant improvement, re-evaluate for complications. 1 Cough persisting ≥3 weeks but <8 weeks is defined as post-infectious cough and may require inhaled corticosteroids if it compromises quality of life. 1, 2