What is the treatment for myiasis (infestation with maggots) on the foot?

Management of Foot Myiasis (Maggot Infestation)

The treatment for myiasis (maggot infestation) on the foot requires immediate surgical debridement with complete removal of all maggots, thorough wound cleansing, and appropriate antibiotic therapy based on infection severity, followed by proper wound care and management of underlying conditions. 1

Initial Assessment and Removal of Maggots

1. Complete maggot removal techniques:

   • Manual extraction using forceps to carefully remove all visible maggots 1
   • Wound irrigation with sterile saline to flush out remaining larvae 1
   • Consider ether application as a non-invasive method to extract wild maggots (causes them to migrate to the surface for easier removal) 2
   • Ensure ALL larvae are completely removed to prevent further tissue damage 1

2. Wound debridement:

   • Sharp debridement is preferred over other methods for removing necrotic tissue and slough 3, 1
   • Remove any surrounding callus or hyperkeratosis 3
   • Evaluate for deeper infection, abscess formation, or bone involvement 3
   • Note: Do not perform aggressive debridement on ischemic wounds without signs of infection 3

Antibiotic Therapy

Select antibiotics based on infection severity:

Infection Severity	Characteristics	Recommended Antibiotic
Mild	Local inflammation with ≤2 cm erythema	Amoxicillin/clavulanate
Moderate	Cellulitis >2 cm or deeper extension	Amoxicillin/clavulanate or ceftriaxone
Severe	Systemic toxicity or metabolic instability	Piperacillin/tazobactam

• Add MRSA coverage when risk factors are present (previous antibiotic exposure, recent hospitalization) 1
• Adjust dosing for patients with renal insufficiency 1
• For osteomyelitis, extend treatment to at least 6 weeks 1

Wound Care Management

1. Cleansing and dressing:

   • Clean wound with sterile saline at each dressing change 1
   • Apply non-adherent contact layer as primary dressing 1
   • Use absorbent foam dressing for exudate management 1
   • Consider antimicrobial dressings if signs of infection persist 1

2. Pressure off-loading:

   • Essential for healing, especially in diabetic foot infections 3, 1
   • Use appropriate devices such as specialized footwear or total contact casts 3
   • Total contact cast is considered the gold standard for off-loading but should be used with caution in patients with severe PAD or active infection 3

3. Monitoring and follow-up:

   • Inspect wound daily initially to monitor for infection progression 1
   • Document wound characteristics including size, depth, surrounding erythema, and drainage 1
   • Look for signs of healing: decreased exudate, improved wound color, reduction in erythema, and development of healthy granulation tissue 1

Special Considerations

1. Vascular assessment:

   • Mandatory for all patients with foot wounds 1
   • If pedal pulses are absent or diminished, consider further vascular evaluation 3
   • Prioritize revascularization when ischemia is present 1

2. Distinguishing therapeutic vs. wild maggots:

   • While therapeutic maggots (Lucilia sericata) can be beneficial in controlled settings for wound debridement 4, 5, 6, wild maggots represent an infection (myiasis) requiring immediate removal 1
   • Therapeutic maggot therapy uses sterile larvae in controlled applications and has shown efficacy in treating chronic wounds resistant to conventional treatment 4, 5

3. For complex or non-healing wounds:

   • Consider interdisciplinary management including wound care specialists, vascular surgeons, and infectious disease specialists 1
   • Advanced wound therapies may be considered for wounds that fail to show 50% reduction after 4 weeks of appropriate management 1

Prevention and Education

• Provide education on proper foot care and prevention of future infections 1
• Regular foot examinations to detect pre-ulcerative lesions 3
• Address underlying factors such as optimizing glycemic control in diabetic patients, smoking cessation, and nutritional support 1
• Proper footwear selection to prevent recurrence 3

Remember that complete removal of all maggots is essential, as any remaining larvae will continue to cause tissue damage. The combination of thorough debridement, appropriate antibiotic therapy, and proper wound care provides the best chance for successful healing and prevention of complications.