How should I manage a wound infection on my leg?

Management of Leg Wound Infection

For a leg wound infection, immediately assess infection severity, perform thorough wound debridement, obtain tissue cultures from the debrided wound base (not swabs), and initiate empirical antibiotics targeting aerobic gram-positive cocci for mild infections or broader coverage for moderate-to-severe infections, with treatment duration of 1-2 weeks for soft tissue infections. 1

Initial Assessment and Classification

Classify the infection severity as mild, moderate, or severe based on the following criteria: 1

• Mild infection: Local signs of inflammation (erythema, warmth, tenderness, purulence) extending ≤2 cm from wound edge, no systemic signs 1
• Moderate infection: Local signs extending >2 cm from wound edge, or involving deeper structures, but no systemic signs 1
• Severe infection: Any infection with systemic signs (fever, leukocytosis, hypotension, metabolic instability) or limb-threatening features 1

Perform the following essential steps at initial evaluation: 1

• Cleanse and debride the wound thoroughly, removing all necrotic tissue and purulent material 1
• Probe the wound to assess depth and determine if bone is palpable (suggests osteomyelitis) 1
• Obtain vital signs and check for systemic signs of infection 1
• Order plain radiographs to evaluate for osteomyelitis, foreign bodies, or gas in tissues 1

Culture Collection Strategy

Obtain cultures based on infection severity and antibiotic history: 1, 2

• Skip cultures for mild infections in antibiotic-naive patients—treat empirically 1, 2
• Obtain cultures for all moderate-to-severe infections, previously treated wounds, or if the patient has systemic illness 1, 2
• Collect tissue specimens via curettage or biopsy from the debrided wound base—this is the gold standard 1, 3
• Avoid swab cultures of undebrided wounds, as these yield misleading results contaminated with colonizing organisms 1, 2
• Order blood cultures for severe infections, especially if systemically ill 1, 3

Empirical Antibiotic Selection

For Mild Infections:

Use oral agents targeting aerobic gram-positive cocci (Staphylococcus, Streptococcus) for 1-2 weeks: 1, 2

• First-line options: Amoxicillin-clavulanate, cephalexin, or dicloxacillin 2, 4
• If penicillin-allergic: Clindamycin 2
• Duration: 1-2 weeks is adequate for most mild soft tissue infections 1

For Moderate Infections:

Use broader-spectrum oral or parenteral coverage for polymicrobial infections: 2, 4

• Oral options: Amoxicillin-clavulanate or levofloxacin 2, 4
• Parenteral options (if unable to tolerate oral): Ampicillin-sulbactam or ceftriaxone plus metronidazole 2
• Cover gram-positives, gram-negatives, and anaerobes 2

For Severe Infections:

Initiate parenteral broad-spectrum therapy immediately, then switch to oral once clinically stable: 1, 2, 4

• Recommended regimens: Piperacillin-tazobactam, imipenem-cilastatin, or ciprofloxacin plus clindamycin 2, 4
• Add MRSA coverage (vancomycin, linezolid, or daptomycin) if prior MRSA history, high local prevalence, or failure to respond to initial therapy 4
• Hospitalization is required for severe infections 1

Critical Adjunctive Measures

Antibiotics alone are insufficient—the following interventions are equally essential: 1, 2, 4

• Aggressive surgical debridement: Remove all necrotic tissue, as antibiotics cannot penetrate devitalized tissue 1, 4
• Drain deep abscesses: Antibiotics cannot adequately penetrate abscess collections 4
• Pressure off-loading: Essential for lower extremity wounds to allow healing 2, 4
• Vascular assessment: Peripheral arterial disease prevents adequate antibiotic delivery and may require revascularization 4
• Optimize metabolic control: Poor glucose control impairs immune function and wound healing 1, 4

Surgical Consultation Indications

Obtain urgent surgical consultation for: 1

• Deep abscesses or compartment syndrome 1
• Necrotizing soft tissue infections or crepitus 1, 4
• Extensive necrosis or gangrene 1
• Bone infection with destroyed soft tissue envelope or protruding bone 1
• All severe infections 1

Treatment Monitoring and Duration

Reassess the patient systematically: 1, 4

• For outpatients: Re-evaluate in 2-4 days, or sooner if worsening 1, 4
• For hospitalized patients: Assess clinically at least once daily 1
• Discontinue antibiotics when signs of infection resolve (not when wound fully heals) 4
• Standard duration: 1-2 weeks for mild-to-moderate soft tissue infections 1
• Extended duration: If osteomyelitis is present, treat for 4-6 weeks minimum (or shorter if all infected bone is surgically removed) 1, 2, 4

Common Pitfalls to Avoid

Do not make these critical errors: 1, 2, 4

• Do not treat clinically uninfected wounds with antibiotics—this promotes resistance without benefit 1, 2
• Do not rely on swab cultures from undebrided wounds—obtain deep tissue specimens after debridement 1, 2
• Do not continue the same antibiotic if infection is clearly worsening—reassess for resistant organisms, inadequate debridement, or osteomyelitis 4
• Do not assume adequate antibiotic penetration in ischemic tissue—vascular assessment is essential 4
• Do not miss underlying osteomyelitis—always probe the wound to bone 4

When Treatment Fails

If the infection does not improve after 2-4 days, systematically address these factors: 4

1. Verify adequate debridement: Remove all necrotic tissue and drain any abscesses 4
2. Reassess for osteomyelitis: Obtain MRI if not improving after 2 weeks 4
3. Evaluate vascular status: Consider revascularization if critical ischemia present 4
4. Review microbiology data: Ensure antibiotic coverage matches isolated pathogens and sensitivities 4
5. Consider multidrug-resistant organisms: Add MRSA coverage or broader gram-negative coverage based on risk factors 4
6. Optimize wound care: Ensure proper off-loading and appropriate dressings 4