Most Likely Diagnosis: Viral Upper Respiratory Infection (Common Cold)
This constellation of symptoms—sinus congestion, low-grade fever, mild sore throat, headache, and red watery eyes—is characteristic of an acute viral upper respiratory infection (URI), commonly known as the common cold. 1, 2
Clinical Reasoning
Viral URIs account for 98–99.5% of acute rhinosinusitis episodes and typically resolve spontaneously within 7–10 days without antibiotics. 3
The symptom profile you describe is classic for viral infection:
- Nasal congestion with rhinorrhea (sinus congestion) is the hallmark of viral rhinitis 1, 2
- Low-grade fever is common in viral URIs, particularly during the first 3 days 4
- Mild sore throat accompanies most viral URIs as part of nasopharyngitis 2, 5
- Headache results from sinus pressure and cytokine release during viral infection 4
- Red watery eyes (conjunctival injection with tearing) indicates viral conjunctivitis, which frequently accompanies viral URIs 4
Most sinus infections are viral—rhinoviruses, influenza viruses, and parainfluenza viruses are the most common causes. 6
Key Distinguishing Features
This presentation does not meet criteria for bacterial sinusitis, which requires at least one of the following 3:
- Persistent symptoms ≥10 days without improvement
- Severe symptoms ≥3–4 consecutive days (fever ≥39°C with purulent discharge and facial pain)
- "Double sickening" (initial improvement followed by worsening)
The presence of low-grade fever (not high fever ≥39°C), mild symptoms, and presumably symptom duration <10 days all point to viral rather than bacterial etiology. 3
Management Approach
No antibiotics are indicated because this is a viral illness. 3, 1 Antibiotics will not help and contribute to antimicrobial resistance. 3
Recommended Symptomatic Treatment
- Analgesics (acetaminophen or ibuprofen) for headache, sore throat, and fever control 3, 1
- Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily to reduce nasal inflammation—supported by strong evidence from multiple randomized controlled trials 3
- Saline nasal irrigation 2–3 times daily for congestion relief and mucus clearance 3
- Oral or topical decongestants for nasal congestion (limit topical agents to ≤3 days to avoid rebound congestion) 3
- Antihistamines may help with watery eyes and rhinorrhea 1
When to Reassess
- Reevaluate at 7–10 days: If symptoms persist beyond 10 days without improvement, the patient now meets criteria for presumed bacterial sinusitis and antibiotics should be considered. 3
- Immediate reevaluation is warranted if symptoms worsen at any time, fever rises to ≥39°C, or "red flag" signs develop (severe headache, visual changes, periorbital swelling, altered mental status). 3
Common Pitfall to Avoid
Do not prescribe antibiotics based solely on purulent nasal discharge or colored mucus—this reflects neutrophilic inflammation common to viral disease, not bacterial infection. 3 The number needed to treat with antibiotics for viral URI is 10–15 patients to achieve one additional cure, while 40–43% experience adverse effects (primarily diarrhea). 3