What is the treatment for myiasis in the trachea?

Treatment of Myiasis in the Trachea

The treatment of tracheal myiasis requires a combination of mechanical removal of larvae with forceps after application of ether to the affected area, along with systemic antifungal therapy such as voriconazole for any associated fungal infection. 1, 2, 3

Diagnosis

• Bronchoscopic evaluation is essential for accurate diagnosis of tracheal myiasis, as radiographic images may not identify the infestation in its initial stages 4
• Biopsy and subsequent culture of suspicious lesions are important to differentiate between myiasis and other infections such as Aspergillus or other fungal species 4
• Laboratory identification of the larvae species is critical for determining appropriate treatment, as different species may require different management approaches 1, 2

Treatment Algorithm

Step 1: Immediate Intervention

• Apply ether to the tracheal wound, which causes spontaneous exit of larvae, making them easier to remove with forceps 1, 3
• Perform mechanical removal of all visible larvae using bronchoscopic procedures 4, 2
• Continue mechanical removal twice daily for at least 3 days to ensure complete eradication of all larvae 2

Step 2: Systemic Therapy

• If associated with Aspergillus infection (common in immunocompromised hosts):
  • Administer voriconazole as first-line therapy (loading dose of 6 mg/kg IV every 12 hours for the first 24 hours, followed by maintenance dose of 4 mg/kg IV every 12 hours) 4, 5
  • For patients who cannot tolerate voriconazole, use liposomal amphotericin B (3-5 mg/kg/day IV) 5
• For immunocompromised patients, systemic antifungal therapy is necessary even if no fungal infection is initially identified, due to high risk of secondary infection 4

Step 3: Local Wound Care

• Clean the tracheostomy site thoroughly after larvae removal 2, 6
• Consider topical application of antifungal solutions such as amphotericin B 3% solution for persistent cases 4
• Ensure proper hygiene of outer and inner tracheostomy tubes 1

Special Considerations

• Immunocompromised patients (those with AIDS, lymphoproliferative disorders, or on chronic corticosteroid therapy) require more aggressive management and closer monitoring 4
• In cases of necrotizing tracheobronchitis with mycelial mass in the trachea, removal of the mass by bronchoscopic procedure is necessary due to poor penetrance of antifungals into the mass 4
• For patients with tracheostomy tubes, regular cleaning and maintenance of the tube is essential to prevent recurrence 1, 2

Prevention

• Implement strict hygiene protocols for tracheostomy care, especially in tropical and subtropical regions 2, 6
• Regular inspection of tracheostomy sites, particularly in immunocompromised or debilitated patients 1, 6
• Consider baseline sinus radiographs or limited CT in high-risk patients 4
• Address predisposing factors such as poor hygiene of tracheostomy tubes and foul-smelling wounds that attract flies 1, 6

Common Pitfalls to Avoid

• Delaying treatment can lead to more extensive tissue damage and potential spread of infestation to deeper tissues 2, 6
• Failing to identify and remove all larvae can result in recurrence and persistent symptoms 1, 2
• Overlooking associated fungal infections, particularly in immunocompromised patients, can lead to treatment failure 4
• Not preserving removed larvae for laboratory identification can hinder species-specific treatment approaches 2, 6