Continue Flucloxacillin for Improving Ankle Cellulitis
Yes, you should continue flucloxacillin at the standard adult dose (500 mg four times daily) for a total treatment duration of 5-7 days minimum, since your cellulitis is demonstrably improving with reduction in swelling from ankle to mid-foot level. 1
Treatment Duration and Monitoring
Complete at least 5-7 days of oral flucloxacillin therapy as this represents the standard evidence-based duration for uncomplicated limb cellulitis that shows clinical improvement. 2, 3
The standard adult dosing is flucloxacillin 500 mg four times daily, which you should maintain throughout the treatment course. 2, 4
Clinical improvement is defined by reduction in affected area, decreased swelling, and resolution of systemic symptoms—all of which you are experiencing. 2
Evidence Supporting Continued Therapy
Recent high-quality research demonstrates that:
Shorter courses (6 days) may result in significantly higher relapse rates (24%) compared to longer courses (12 days) with only 6% relapse, though the optimal duration remains somewhat uncertain. 3
Treatment success rates with flucloxacillin monotherapy for limb cellulitis reach approximately 81-87% when given for 5-7 days. 2
Flucloxacillin achieves adequate tissue penetration in infected lower extremity tissues, maintaining concentrations above the minimum inhibitory concentration for Staphylococcus aureus (the primary pathogen) for approximately 7 hours after each dose. 5
Important Caveats
Do not stop antibiotics prematurely even though you're improving—this is a common pitfall that increases relapse risk. 3
Watch for warning signs requiring urgent reassessment:
- Worsening pain disproportionate to visible findings
- Spreading erythema despite 48-72 hours of antibiotics
- Development of blisters, skin darkening, or tissue breakdown
- Fever, confusion, or systemic deterioration
- These features suggest necrotizing fasciitis or treatment failure requiring immediate medical evaluation. 1
Monitor for flucloxacillin side effects, particularly diarrhea (occurs in approximately 9% of patients on flucloxacillin alone). 2
When to Seek Medical Review
Return for clinical reassessment if: