Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Myiasis Treatment & Management

  • Author: Adam B Blechman, MD; Chief Editor: Joe Alcock, MD, MS  more...
 
Updated: May 13, 2016
 

Prehospital Care

Prehospital care is not required.

Next

Emergency Department Care

Occlusion/suffocation approaches

This noninvasive approach includes placing petroleum jelly, liquid paraffin, beeswax or heavy oil, or bacon strips over the central punctum and has been used to coax the larvae to emerge spontaneously head-first over the course of several hours, at which time, tweezers (or forceps) aid in the capture. Enlarging the punctum beforehand may make it easier to remove the larvae later as it emerges and is usually needed for botflies.[17] Anecdotal evidence has shown the larvae to emerge within 3-24 hours after application of suffocating material.[18, 19]

These approaches take advantage of the larva's oxygen requirements, encouraging it to exit on its own. However, the covering should not be restrictive (eg, nail polish) because this may asphyxiate the larva without causing it to migrate out of the skin. If the larva does asphyxiate, then surgical removal is necessary.

Surgical removal with local anesthesia

The skin lesion is locally anesthetized with lidocaine and excised surgically followed by primary wound closure. Alternatively, lidocaine can be injected forcibly into the base of the lesion in an attempt to create enough fluid pressure to extrude the larvae out of the punctum.[20] The larvae are anchored deeply to the subcutaneous by anterior hooklets and it is important to remove all parts from the site to prevent a foreign body reaction.[2] Another surgical approach would be to perform a 4- to 5-mm punch excision of the overlying punctum and surrounding skin to gain better access to and visibility of the larva. The larva can then be removed carefully using toothed forceps (experience of B.B. Wilson, MD).

The larva should not be forcibly removed through the central punctum because its tapered shape with rows of spines and hooks prevents simple extrusion.

Furthermore, care should be taken to avoid lacerating the larva because retained larval parts may precipitate foreign body reaction. After removal of the larvae, antiseptic dressings, thorough cleansing, and debridement are indicated, as well as antibiotics if secondary infection is present.

Systemic/topical ivermectin

An alternative treatment for all types of myiasis is oral ivermectin or topical ivermectin (1% solution), proven especially helpful with oral and orbital myiasis.

Wound myiasis

Wound myiasis requires debridement with irrigation to eliminate the larvae from the wound or surgical removal. Application of chloroform, chloroform in light vegetable oil, or ether, with removal of the larvae under local anesthesia, has been advocated for wound myiasis.[1, 20]

Surgical removal is not required unless requested by the patient, as the larvae are naturally sloughed within 5-7 weeks.

Previous
Next

Consultations

Depending on the location of the larval infestation, dermatologists (wound and furuncular myiasis), ophthalmologists (ophthalmomyiasis), or otorhinolaryngologists (oral, facial, nasal myiasis) may need to be consulted.

Previous
Next

Complications

Care must be taken to extract the larva whole, otherwise a considerable foreign body reaction may ensue. Also, in the case of secondary pyogenic infection, appropriate antibiotics should be administered.

Myiasis can be a portal of entry for Clostridium tetani; therefore, vaccination should be considered in affected individuals.[1]

Previous
Next

Prevention

Individuals traveling to rural endemic areas should be covered at all times with long-sleeved shirts, pants, and hats. At night, sleeping on raised beds, in screened rooms, or under a mosquito net is appropriate. Insect repellents are also recommended. Clothing should be hot-ironed and dried appropriately to remove any residual eggs in areas endemic to tumbu flies.[2]

To prevent wound myiasis, simple antisepsis is usually adequate. Wounds should be cleaned and irrigated intermittently, and proper dressings should be applied. Patients with any type of wound should not be permitted to sleep outside and, if in an indoor or hospital environment, the windows should never be opened, unless properly screened.[20]

Previous
 
 
Contributor Information and Disclosures
Author

Adam B Blechman, MD Resident Physician, Department of Dermatology, University of Virginia Health System

Adam B Blechman, MD is a member of the following medical societies: American Academy of Dermatology, American Society for Dermatologic Surgery, Medical Society of Virginia

Disclosure: Nothing to disclose.

Coauthor(s)

Barbara B Wilson, MD Edward P Cawley Associate Professor, Department of Dermatology, University of Virginia School of Medicine

Barbara B Wilson, MD is a member of the following medical societies: Alpha Omega Alpha, Medical Society of Virginia, Sigma Xi, American Academy of Dermatology

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Chief Editor

Joe Alcock, MD, MS Associate Professor, Department of Emergency Medicine, University of New Mexico Health Sciences Center

Joe Alcock, MD, MS is a member of the following medical societies: American Academy of Emergency Medicine

Disclosure: Nothing to disclose.

Additional Contributors

Robert L Norris, MD Professor, Department of Emergency Medicine, Stanford University Medical Center

Robert L Norris, MD is a member of the following medical societies: American College of Emergency Physicians, Society for Academic Emergency Medicine, International Society of Toxinology, American Medical Association, California Medical Association, Wilderness Medical Society

Disclosure: Nothing to disclose.

Acknowledgements

Eleni Grammatikopoulou, MD Visiting Physician, University of Virginia School of Medicine

Disclosure: Nothing to disclose

References
  1. Bolognia JL, Jorizzo JL, Rapini R. Cutaneous myiasis. Dermatology. 2nd ed. Mosby Elsevier; 2008. Vol 1: 1300-01.

  2. Diaz JH. The epidemiology, diagnosis, management, and prevention of ectoparasitic diseases in travelers. J Travel Med. 2006 Mar-Apr. 13(2):100-11. [Medline].

  3. Burns T, Breathnach S, Cox N, Griffiths C. Diseases caused by arthropods and other noxious animals. Rook's Textbook of Dermatology. 7th ed. Malden, MA: Blackwell Publishing; 2004. Vol 2: 33.8 - 11.

  4. Auerbach PS. Arthropod envenomation and parasitism. Wilderness Medicine. 5th ed. Philadelphia, PA: Mosby Elsevier; 2007. 969-974.

  5. Davis RF, Johnston GA, Sladden MJ. Recognition and management of common ectoparasitic diseases in travelers. Am J Clin Dermatol. 2009. 10(1):1-8. [Medline].

  6. James, WD, Berger, TG, Elston, DM. Myiasis. Andrews’ Diseases of the Skin. 11th ed. Elsevier; 2011. 438.

  7. Mandell GL, Bennett JE, Dolin R. Infectious diseases and their etiologic agents. Principles and Practice of Infectious Diseases. 5th ed. Philadelphia, PA: Churchill Livingstone; 2000. Vol 2: 2976-2979.

  8. Cestari TF, Pessato S, Ramos-e-Silva M. Tungiasis and myiasis. Clin Dermatol. 2007 Mar-Apr. 25(2):158-64. [Medline].

  9. Schwartz E, Gur H. Dermatobia hominis myiasis: an emerging disease among travelers to the Amazon basin of Bolivia. J Travel Med. 2002 Mar-Apr. 9(2):97-9. [Medline].

  10. Masoodi M, Hosseini K. External ophthalmomyiasis caused by sheepbotfly (Oestrus Ovis) larva: a report of 8 cases. Arch Iran Med. 2004. 7:136-139.

  11. Aydin E, Uysal S, Akkuzu B, et al. Nasal myiasis by fruit fly larvae: a case report. Eur Arch Otorhinolaryngol. 2006 Dec. 263(12):1142-3. [Medline].

  12. Sharma H, Dayal D, Agrawal SP. Nasal myiasis: review of 10 years experience. J Laryngol Otol. 1989 May. 103(5):489-91. [Medline].

  13. Terterov S, Taghva A, MacDougall M, Giannotta S. Posttraumatic human cerebral myiasis. World Neurosurg. 2010 May. 73(5):557-9. [Medline].

  14. Garvin KW, Singh V. Case report: cutaneous myiasis caused by Dermatobia hominis, the human botfly. Travel Med Infect Dis. 2007 May. 5(3):199-201. [Medline].

  15. Ofordeme KG, Papa L, Brennan DF. Botfly myiasis: a case report. CJEM. 2007 Sep. 9(5):380-2. [Medline].

  16. Quintanilla-Cedillo MR, Leon-Urena H, Contreras-Ruiz J, Arenas R. The value of Doppler ultrasound in diagnosis in 25 cases of furunculoid myiasis. Int J Dermatol. 2005 Jan. 44(1):34-7. [Medline].

  17. Maier H, Hönigsmann H. Furuncular myiasis caused by Dermatobia hominis, the human botfly. J Am Acad Dermatol. 2004 Feb. 50(2 Suppl):S26-30. [Medline].

  18. Brewer TF, Wilson ME, Gonzalez E, Felsenstein D. Bacon therapy and furuncular myiasis. JAMA. 1993 Nov 3. 270(17):2087-8. [Medline].

  19. Ruch DM. Botfly myiasis. Arch Dermatol. 1967 Dec. 96(6):677-80. [Medline].

  20. Lebwohl MG, Heymann WR, Berth-Jones J, Coulson I. Myiasis. Treatment of Skin Diseases. Comprehensive Therapeutic Strategies. 2nd ed. Elesevier-Mosby; 2006. 420-421.

  21. Osorio J, Moncada L, Molano A, et al. Role of ivermectin in the treatment of severe orbital myiasis due to Cochliomyia hominivorax. Clin Infect Dis. 2006 Sep 15. 43(6):e57-9. [Medline].

  22. Costa DC, Pierre-Filho Pde T, Medina FM, Mota RG, Carrera CR. Use of oral ivermectin in a patient with destructive rhino-orbital myiasis. Eye. 2005 Sep. 19(9):1018-20. [Medline].

  23. Clyti E, Nacher M, Merrien L, et al. Myiasis owing to Dermatobia hominis in a HIV-infected subject: Treatment by topical ivermectin. Int J Dermatol. 2007 Jan. 46(1):52-4. [Medline].

 
Previous
Next
 
Mature larva of the Dermatobia hominis fly; rows of hooks apparent on its tapered body. Image courtesy of Kenneth E Greer.
Boil-like lesion on toe of a patient with botfly myiasis; the central punctum is apparent. Image courtesy of Kenneth E Greer.
Boil-like lesions on a patient with botfly myiasis; the central punctum is apparent. Image courtesy of Kenneth E Greer.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.