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 region[1]
  • Bacterial superinfection is rare[2]

Clinical Features

Myiasis in patient neck
  • Erythematous papule with central pore (allows for larval respiration)[2]
  • Sensation of movement within lesion
  • Serous drainage

Differential Diagnosis

Travel-related skin conditions

See also domestic U.S. ectoparasites

Domestic U.S. Ectoparasites

See also travel-related skin conditions

Evaluation

  • Clinical diagnosis

Management[2]

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

See Also

External Links

References

  1. https://www.cdc.gov/parasites/myiasis/faqs.html Accessed 02/06/17
  2. 2.0 2.1 2.2 McGraw TA. Turiansky GW. Cutaneous myiasis. Journal of the American Academy of Dermatology. 58(6):907-26; quiz 927-9, 2008 Jun.