What is the treatment for a patient with a foot infection and myiasis?

Management of Foot Infection with Myiasis

For a foot infection with maggots (myiasis), immediate surgical debridement, removal of maggots, wound cleansing, and appropriate antibiotic therapy are required, followed by proper wound care and consideration of underlying conditions. 1

Initial Assessment and Management

Immediate Actions:

1. Complete removal of all maggots 1

   • Use forceps for manual extraction
   • Irrigate the wound with sterile saline to flush out remaining larvae
   • Ensure all larvae are removed to prevent further tissue damage

2. Surgical debridement 1

   • Remove all necrotic tissue and slough
   • Debride any callus surrounding the wound
   • Evaluate for deep space infection, abscess, or bone involvement

3. Wound assessment 1, 2

   • Evaluate depth and extent of infection
   • Assess for signs of osteomyelitis (probe-to-bone test)
   • Document wound characteristics (size, depth, appearance)
   • Check for crepitus, gas in tissues, or extensive necrosis requiring urgent surgical intervention

Antibiotic Therapy

Empiric Antibiotic Selection: 1, 2

• Mild infection (localized, <2cm erythema): Amoxicillin-clavulanate
• Moderate infection (>2cm erythema or deeper tissue): Broader spectrum coverage
• Severe infection (systemic signs): Parenteral antibiotics (e.g., piperacillin-tazobactam)

Duration of Therapy: 1

• Mild infections: 1-2 weeks
• Moderate infections: 2-4 weeks
• Severe infections: 2-4 weeks
• Osteomyelitis: At least 4-6 weeks (shorter if infected bone completely removed)

Wound Care Protocol

Ongoing Management: 1, 2

1. Proper wound cleansing

   • Use sterile saline for irrigation
   • Clean wound at each dressing change

2. Appropriate dressing selection

   • Non-adherent contact layer as primary dressing
   • Absorbent foam dressing for exudate management
   • Consider antimicrobial dressings if signs of infection persist

3. Off-loading pressure from the wound

   • Essential for healing, especially in diabetic foot infections
   • Use appropriate devices (specialized footwear, casts, etc.)

4. Regular wound reassessment

   • Monitor for signs of healing or worsening infection
   • Adjust treatment plan accordingly

Special Considerations

Vascular Assessment: 1

• Evaluate for peripheral arterial disease
• Consider urgent vascular consultation if signs of critical limb ischemia
• Early revascularization may be necessary for wound healing

Interdisciplinary Care Team Involvement: 1

• Refer to an interdisciplinary care team for complex infections
• Team should include specialists in wound care, infectious disease, and vascular surgery

Warning Signs Requiring Urgent Intervention: 1

• Crepitus or tissue gas on imaging
• Extensive necrosis or gangrene
• Systemic inflammatory response
• New onset wound anesthesia
• Pain disproportionate to clinical findings

Follow-up Care

• Early and careful follow-up to ensure treatment effectiveness 1
• Regular foot examinations to detect pre-ulcerative lesions 2
• Patient education on foot care and prevention of future infections 1

Important Caveats

1. Maggot therapy distinction: While therapeutic maggots can be beneficial in controlled settings for wound debridement, wild maggots in wounds represent an infection (myiasis) that requires immediate removal 1, 3, 4

2. Bacterial considerations: Maggot-infested wounds may harbor unusual pathogens like Wohlfahrtiimonas chitiniclastica, which should be considered if standard antibiotic therapy fails 5

3. Risk factors: Poor hygiene, neglected wounds, and inadequate wound care are primary risk factors for myiasis 6, 4

4. Prevention: Patient education about proper wound care and hygiene is essential to prevent recurrence 1, 6