Most Likely Diagnosis and Management
This is a classic presentation of acute viral upper respiratory tract infection (URI) with Upper Airway Cough Syndrome (UACS), and the patient should be started immediately on a first-generation antihistamine/decongestant combination such as brompheniramine with sustained-release pseudoephedrine twice daily. 1
Clinical Reasoning for Diagnosis
The constellation of symptoms strongly points to acute viral URI with UACS:
- Non-productive cough with occasional clear sputum indicates upper airway irritation rather than bacterial infection, as clear sputum does not suggest bacterial etiology 2
- Sinus pressure, post-nasal drip, and sneezing are hallmark symptoms of UACS 1, 3
- Absence of fever, chest pain, or dyspnea makes pneumonia highly unlikely—only 5-10% of patients with acute cough have pneumonia, and without focal chest signs this probability drops to 2% 4
- Generalized myalgia with improving symptoms is consistent with viral URI 5
- No history of allergic rhinitis suggests non-allergic rhinitis as the underlying mechanism 1
The improving trajectory of symptoms (sore throat and nasal drip already better) confirms this is likely a self-limited viral process, but the persistent cough warrants symptomatic treatment.
First-Line Treatment Algorithm
Immediate initiation:
- First-generation antihistamine/decongestant combination (e.g., brompheniramine 6 mg/pseudoephedrine 120 mg sustained-release twice daily OR chlorpheniramine/phenylephrine) 1, 3
- This is the most effective evidence-based treatment for UACS, with improvement expected within days to 1-2 weeks 1
- First-generation antihistamines are essential—newer non-sedating antihistamines (cetirizine, loratadine, fexofenadine) are ineffective for non-allergic UACS and should not be used 1, 2
Supportive measures:
- Nasal saline irrigation to mechanically remove secretions and improve mucociliary clearance 1, 2
- Adequate hydration (address the decreased fluid intake over past 48 hours) 2
- Analgesics as needed for generalized achiness 2
- Sleep with head of bed elevated 2
When to Escalate or Reassess
If cough persists after 1-2 weeks of antihistamine/decongestant:
- Add intranasal corticosteroid (fluticasone 100-200 mcg daily) for a 1-month trial 1, 3
- Consider adding inhaled ipratropium bromide 2-3 puffs four times daily, which has the strongest evidence for post-infectious cough 3
If cough persists beyond 2 weeks despite adequate upper airway treatment:
- Sequentially evaluate for asthma/cough-variant asthma (consider bronchoprovocation testing or empiric inhaled corticosteroid trial) 1
- Evaluate for GERD (initiate omeprazole 20-40 mg twice daily before meals for at least 8 weeks plus dietary modifications) 1
If cough persists beyond 8 weeks:
- Order chest X-ray to rule out other pathology 3
- Refer to specialized cough clinic for systematic evaluation 1
Why Antibiotics Are NOT Indicated
- Clear sputum production does not indicate bacterial infection and should not trigger antibiotic use 2
- Most acute sinusitis is viral and does not require antibiotics 2
- Antibiotics should only be considered if symptoms persist ≥10 days without improvement or worsen within 10 days after initial improvement 2
- The improving trajectory of her sore throat and nasal drip confirms viral etiology 5, 6
Critical Pitfalls to Avoid
- Do not prescribe newer-generation antihistamines—they lack the anticholinergic properties needed for UACS and are ineffective for acute cough 1, 2
- Do not prescribe antibiotics based solely on cough character or sputum production—the presence of clear sputum does not indicate bacterial infection 4, 2
- Do not overlook "silent" UACS—approximately 20% of patients have no obvious post-nasal drip symptoms yet still respond to treatment 1
- Monitor for decongestant side effects including insomnia, irritability, palpitations, and hypertension 1
- To minimize sedation from first-generation antihistamines, start with once-daily dosing at bedtime for a few days before increasing to twice-daily 1