What is the likely diagnosis and appropriate management for nasal congestion accompanied by sharp pain radiating to the left temple?

Acute Bacterial Sinusitis with Unilateral Headache

Your symptoms of nasal congestion with sharp pain radiating to the left temple strongly suggest acute bacterial sinusitis, and you should start amoxicillin-clavulanate 875 mg/125 mg twice daily for 10-14 days, combined with intranasal corticosteroids and saline irrigation. 1, 2, 3

Clinical Diagnosis

Your presentation fits the classic pattern of acute bacterial sinusitis:

• Nasal congestion with purulent rhinorrhea, facial/dental pain, and headache are the hallmark symptoms of acute bacterial sinusitis in adults 1
• Unilateral temple pain radiating from the sinuses indicates maxillary or frontal sinus involvement, which commonly presents with facial pressure and headache 1
• Pain over the sinuses is a key distinguishing feature that separates bacterial sinusitis from viral upper respiratory infections 1

When Antibiotics Are Indicated

You should receive antibiotics if you meet any of these criteria:

• Symptoms persisting ≥10 days without improvement (purulent discharge plus obstruction or facial pain) 2
• Severe symptoms: fever ≥39°C lasting ≥3-4 consecutive days with purulent discharge and facial pain 2
• "Double sickening": initial improvement followed by worsening after 5-6 days 2

First-Line Antibiotic Treatment

Amoxicillin-clavulanate 875 mg/125 mg twice daily is the preferred first-line antibiotic, not plain amoxicillin, because:

• It provides 90-92% predicted efficacy against the three most common pathogens: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 2
• The clavulanate component covers β-lactamase-producing organisms (30-40% of H. influenzae and M. catarrhalis isolates produce β-lactamase) 2
• Treatment duration should be 10-14 days, or continue for 7 days after symptoms resolve 1, 3

Essential Adjunctive Therapies (Not Optional)

You must add intranasal corticosteroids and saline irrigation—these are not optional add-ons:

• Intranasal corticosteroids (fluticasone, mometasone, or budesonide) twice daily reduce mucosal inflammation and accelerate symptom resolution, with strong RCT evidence 2, 4
• High-volume saline nasal irrigation 2-3 times daily clears mucus and reduces edema 2
• Analgesics (acetaminophen or ibuprofen) for pain control 3

Reassessment Timeline

You must be reassessed at specific intervals—do not wait indefinitely:

• At 3-5 days: If no improvement, switch to high-dose amoxicillin-clavulanate (2 g/125 mg twice daily) or a respiratory fluoroquinolone 1, 2, 3
• At 7 days: If symptoms persist or worsen, reconfirm the diagnosis and exclude complications 2

Red Flags Requiring Urgent Evaluation

Seek immediate medical attention if you develop any of these:

• Orbital swelling, pain, or visual changes (diplopia, proptosis) 1
• Swelling of the forehead 1
• Severe headache with altered mental status 2
• Periorbital inflammation, edema, or erythema 1

These symptoms suggest orbital cellulitis, meningitis, or intracranial abscess—life-threatening complications requiring urgent CT imaging and possible surgical intervention 1, 2

What NOT to Do

Avoid these common pitfalls:

• Do not obtain routine CT imaging for uncomplicated acute sinusitis—up to 87% of viral URIs show sinus abnormalities on imaging, which cannot differentiate bacterial from viral disease 2
• Do not use macrolides (azithromycin)—resistance exceeds 20-25% for S. pneumoniae and H. influenzae 2
• Do not use trimethoprim-sulfamethoxazole—resistance rates are 50% for S. pneumoniae 2
• Do not use first-generation cephalosporins (cephalexin)—inadequate coverage against β-lactamase-producing H. influenzae 2

Penicillin Allergy Alternatives

If you have a penicillin allergy:

• Non-severe allergy: Use a second- or third-generation cephalosporin (cefuroxime, cefpodoxime, or cefdinir) for 10 days—cross-reactivity is negligible 2
• Severe/anaphylactic allergy: Use a respiratory fluoroquinolone (levofloxacin 500 mg daily for 10-14 days or moxifloxacin 400 mg daily for 10 days) 2

When to Refer to ENT

Refer to otolaryngology if:

• No improvement after 7 days of appropriate second-line antibiotics 2
• Suspected complications (orbital cellulitis, meningitis, intracranial abscess) 2
• Recurrent sinusitis (≥3 episodes per year)—evaluate for underlying allergic rhinitis, immunodeficiency, or anatomic abnormalities 1, 2