Treatment of Myiasis Under the Toenail
The primary treatment for myiasis under the toenail is manual removal of all larvae, which can be facilitated by topical application of turpentine oil or occlusive agents to force larvae to emerge, followed by systemic ivermectin if needed for extensive infestation. 1, 2
Immediate Mechanical Removal
- Manual extraction of all larvae is the cornerstone of treatment and must be performed completely to prevent ongoing tissue damage. 1
- Topical turpentine oil application can help facilitate larval removal by forcing the larvae to migrate out of the tissue. 2
- Occlusive substances (petroleum jelly, paraffin) can be applied to suffocate larvae and force them to surface for easier extraction. 1
- Surgical debridement of the periungual tissue may be necessary if there is significant tissue destruction or if larvae are deeply embedded. 2
Systemic Antiparasitic Therapy
- Oral ivermectin should be administered for extensive infestations or when complete manual removal is difficult. 2
- Ivermectin is particularly useful when multiple larvae are present or anatomical constraints make complete extraction challenging. 2
Wound Care Considerations
- Traditional wound cleansing solutions (isopropyl alcohol, Dakin's solution, iodine, hydrogen peroxide) have limited effectiveness against maggots, with maximum mortality rates of only 46% even with repeated applications. 3
- Do not rely on wound cleansing solutions alone as they will not achieve complete eradication of larvae. 3
- Supplemental mechanical removal is always necessary as no topical antiseptic achieves 100% maggot mortality. 3
Antibiotic Coverage
- Broad-spectrum antibiotics should be considered if there are signs of secondary bacterial infection, particularly in cases with tissue necrosis or systemic symptoms. 4
- Morganella morganii and other gram-negative organisms can cause septicemia secondary to myiasis, especially in immunocompromised or elderly patients. 4
- Blood cultures should be obtained if systemic infection is suspected. 4
Important Clinical Pitfalls
- The periungual location can mimic an ingrown toenail, leading to delayed diagnosis—always inspect for larvae movement in inflamed periungual tissue. 5
- Incomplete larval removal will result in continued tissue destruction and potential secondary infection. 1
- Antibiotic therapy alone without larval extraction is insufficient and will not resolve the infestation. 1