A 71-year-old woman on prednisolone for polymyalgia rheumatica completes a course of levofloxacin for sinusitis. Ten days later she complains of severe heel pain and swelling that worsens on walking. The most likely explanation is:

• A Reactive arthritis triggered by the preceding infection
• B Sinusitis-related septic emboli seeding the tendon sheath
• C Steroid withdrawal arthropathy affecting the ankle joint
• D Fluoroquinolone-induced Achilles tendinitis, potentiated by corticosteroid use ✓

Explanation

Fluoroquinolones impair tenocyte proliferation and matrix metalloproteinase regulation, causing tendinitis and tendon rupture, classically involving the Achilles tendon, typically within days to weeks of exposure. Concurrent systemic corticosteroids substantially increase this risk, and elderly patients are also more susceptible. The presentation here is classic for drug-induced tendinopathy. Reactive arthritis usually follows urogenital or enteric infection with a latency of weeks, and septic emboli would be accompanied by systemic features.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.