Management of Phlegmon of the Calf
A phlegmon of the calf should be surgically drained, particularly if it is large, symptomatic, or shows signs of progression despite antibiotic therapy. While the evidence specifically addressing calf phlegmons is limited, management principles can be extrapolated from guidelines on other inflammatory collections.
Diagnostic Approach
- Obtain imaging (ultrasound or CT) to confirm the diagnosis and determine:
- Size of the phlegmon
- Presence of loculations
- Whether it has progressed to abscess formation
- Contrast-enhanced ultrasound can accurately differentiate between phlegmon and abscess with excellent specificity 1
Treatment Algorithm
Initial Management
Start broad-spectrum antibiotics immediately
- Coverage should include both aerobic and anaerobic organisms 2
- Appropriate regimens include:
- Piperacillin-tazobactam
- Cephalosporin + metronidazole
- Fluoroquinolone + metronidazole
Surgical drainage indications:
- Large phlegmon (>3 cm)
- Symptomatic collection causing pain or functional limitation
- Signs of systemic infection/sepsis
- Failure to improve with antibiotics within 48-72 hours
- Progression to abscess formation
Surgical Approach
- Technique: Thorough surgical debridement with adequate drainage
- Post-procedure: Consider iodoform packing for complete resolution 3
- Timing: Early intervention is preferred to prevent progression and spread along tissue planes
Special Considerations
Monitoring and Follow-up
- Close clinical monitoring during initial 48-72 hours of antibiotic therapy
- Follow-up imaging to assess resolution of inflammation
- Continue antibiotics until clinical improvement and resolution of inflammatory markers
Potential Complications
- Progression to abscess formation
- Spread of infection to adjacent tissues
- Development of compartment syndrome
- Sepsis if inadequately treated
Evidence Analysis
While the 2020 WSES guidelines 2 primarily address appendiceal phlegmons, the principles of management can be applied to other anatomical locations. For inflammatory collections, early drainage is recommended when the collection is loculated or large, as these factors are associated with poorer outcomes.
The case report by the Journal of the American Podiatric Medical Association 3 specifically demonstrated that a plantar foot phlegmon required surgical debridement and packing for successful resolution after being recalcitrant to antibiotics alone.
For head and neck phlegmons, which can be life-threatening, surgical incision and drainage along with antibiotics form the cornerstone of treatment 4, further supporting the approach of surgical intervention for significant phlegmons.
Pitfalls to Avoid
- Delaying surgical intervention when antibiotics fail to produce improvement
- Inadequate drainage or incomplete debridement
- Insufficient antibiotic coverage (must cover both aerobic and anaerobic organisms)
- Failure to monitor for progression or complications
In conclusion, while small, uncomplicated phlegmons may respond to antibiotics alone, surgical drainage should be strongly considered for calf phlegmons that are large, symptomatic, or not responding to conservative management.