Myiasis
Background
- Caused by Diptera species. Dermatobia hominis (botfly) is most common cause in North America
- Cutaneous (includes follicular, wound, and migratory) type is most common
- Can also occur in mouth, urogenital, ophthalmic, nasopharyngeal location
- Typically occurs in tropical and subtropical areas. US cases typically due to travel to endemic regionCite error: Closing
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Clinical Features
- Erythematous papule with central pore (allows for larval respiration)[1]
- Sensation of movement within lesion
- Serous drainage
Differential Diagnosis
- Papules
- Insect bites
- Scabies
- Seabather's eruption
- Cercarial dermatitis (Swimmer's Itch)
- Macular
- Sub Q Swelling and Nodules
- Ulcers
- Tropical pyoderma
- Leishmaniasis
- Mycobacterium marinum
- Buruli ulcer
- Dracunculiasis (Guinea Worm disease)
- Linear and Migratory Lesions
- Cutaneous larvae migrans
- Photodermatitis
See also domestic U.S. ectoparasites
Domestic U.S. Ectoparasites
See also travel-related skin conditions
Evaluation
- Clinical diagnosis
Management[1]
If entire larvae is not removed, severe inflammatory response occurs
- Occlusion of central pore with petroleum jelly or mineral oil interrupts oxygen supply and causes larvae to migrate to surface where it can be grasped with forceps and removed
- Can take up to 24 hours
- Manual removal by squeezing out larvae
- Surgical removal by making incision over larvae and removing with forceps
- Ivermectin - single PO dose or topical application
- Wound myiasis requires surgical debridement
- Ocular, nasopharyngeal, urogenital myiasis should prompt appropriate specialist consultation for management
Disposition
- Cutaneous myiasis generally may be discharged after removal
- Disposition of other forms based on discussion with specialist