What is the appropriate management for an adult who was treated for an acute sinus infection with amoxicillin, recently stopped a short course of oral steroids due to side effects, and now, one week later, has persistent yellow sputum and severe diffuse muscle and joint pain that prevents ambulation?

Urgent Evaluation for Severe Musculoskeletal Symptoms After Fluoroquinolone Therapy

This patient requires immediate discontinuation of amoxicillin and urgent evaluation for fluoroquinolone-associated adverse effects, specifically tendinopathy or myopathy, given the severe muscle and joint pain preventing ambulation one week after completing a steroid pack.

Immediate Actions Required

• Stop amoxicillin immediately – the persistent yellow sputum after one week of appropriate antibiotic therapy indicates treatment failure, and continuing an ineffective antibiotic provides no benefit while delaying appropriate management. 1

• Obtain urgent history regarding recent fluoroquinolone exposure – if this patient received a fluoroquinolone (levofloxacin or moxifloxacin) during the initial treatment course, the severe diffuse muscle and joint pain preventing ambulation may represent fluoroquinolone-associated tendinopathy or myopathy, which is a serious adverse effect requiring immediate drug cessation. 1, 2

• Assess for red-flag complications – severe headache, visual changes, periorbital swelling, altered mental status, or cranial nerve deficits would indicate orbital cellulitis, meningitis, or intracranial abscess requiring emergency imaging and ENT referral. 1

Diagnostic Reassessment

• Confirm the diagnosis of acute bacterial rhinosinusitis – persistent purulent nasal discharge (yellow sputum) for ≥10 days meets criteria for bacterial sinusitis, but the severe systemic symptoms (inability to walk due to muscle/joint pain) are atypical and suggest either a complication or drug-related adverse effect. 1

• Consider alternative diagnoses – the constellation of severe muscle pain, joint pain preventing ambulation, and persistent respiratory symptoms one week after stopping steroids raises concern for:

  • Fluoroquinolone-associated tendinopathy/myopathy (if fluoroquinolone was used)
  • Viral myositis or post-viral syndrome
  • Steroid withdrawal syndrome (though less likely to cause inability to walk)
  • Complicated sinusitis with systemic inflammatory response 1

Second-Line Antibiotic Management

• Switch to high-dose amoxicillin-clavulanate 875 mg/125 mg twice daily for 10–14 days as the preferred second-line regimen after amoxicillin failure, providing 90–92% predicted clinical efficacy against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis while maintaining coverage of drug-resistant Streptococcus pneumoniae. 1

• Alternative: respiratory fluoroquinolone (levofloxacin 500 mg once daily for 10–14 days or moxifloxacin 400 mg once daily for 10 days) if the patient cannot tolerate amoxicillin-clavulanate or has documented severe penicillin allergy – however, if a fluoroquinolone was already used and caused the current musculoskeletal symptoms, this class is absolutely contraindicated. 1, 2

• Reassess at 3–5 days after switching antibiotics – persistent lack of improvement requires ENT referral, sinus cultures (direct aspiration or endoscopic sampling), and CT imaging to exclude complications. 1

Essential Adjunctive Therapies

• Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily significantly reduce mucosal inflammation and accelerate symptom resolution; supported by strong evidence from multiple randomized controlled trials. 1

• Saline nasal irrigation 2–3 times daily provides symptomatic relief and aids mucus clearance. 1

• Analgesics (acetaminophen or ibuprofen) for pain control – given the severity of musculoskeletal pain, scheduled dosing rather than as-needed may be appropriate. 1

Critical Pitfall: Steroid Discontinuation

• The abrupt discontinuation of the steroid pack due to side effects may have contributed to rebound inflammation – systemic corticosteroids provide modest short-term symptom relief in acute sinusitis when combined with antibiotics, but stopping them abruptly can lead to symptom recurrence. 3, 4

• Do not restart systemic corticosteroids without concurrent antibiotics when bacterial sinusitis is suspected, as this may suppress the immune response and allow bacterial proliferation. 1

• Short-term oral corticosteroids (typically 5 days) may be considered for marked mucosal edema or treatment failure, but only after confirming the patient can tolerate them and only in combination with appropriate antibiotics. 3, 1

Urgent Referral Indications

• Refer to ENT immediately if any of the following are present:
  • No improvement after 7 days of appropriate second-line antibiotic therapy 1
  • Worsening symptoms at any point (increasing facial pain, fever, purulent drainage) 1
  • Signs of complications (severe headache, visual changes, periorbital swelling, altered mental status) 1
  • Severe musculoskeletal symptoms preventing ambulation – this is not a typical presentation of uncomplicated sinusitis and warrants specialist evaluation 1

Key Diagnostic Considerations

• The severe muscle and joint pain preventing ambulation is the most concerning feature – this degree of systemic involvement is atypical for uncomplicated acute bacterial sinusitis and suggests either:

  • A serious drug-related adverse effect (especially if fluoroquinolone was used)
  • A complication of sinusitis (septic arthritis, osteomyelitis, though rare)
  • A concurrent viral myositis or post-viral syndrome
  • An underlying inflammatory or rheumatologic condition unmasked by the infection 1

• Persistent yellow sputum after one week of amoxicillin indicates treatment failure – this may be due to β-lactamase-producing organisms (H. influenzae or M. catarrhalis) or drug-resistant S. pneumoniae, both of which require escalation to amoxicillin-clavulanate or a fluoroquinolone. 1

Bottom Line

This patient requires urgent evaluation for the severe musculoskeletal symptoms, immediate discontinuation of ineffective amoxicillin, and escalation to high-dose amoxicillin-clavulanate 875/125 mg twice daily for 10–14 days (or a respiratory fluoroquinolone if no prior fluoroquinolone exposure and no contraindications). The inability to walk due to muscle and joint pain is not explained by uncomplicated sinusitis alone and mandates investigation for drug-related adverse effects (especially fluoroquinolone toxicity if that class was used), complications of sinusitis, or alternative diagnoses. If symptoms do not improve within 3–5 days of the new antibiotic regimen, or if any red-flag features develop, immediate ENT referral and imaging are required. 1