Cutaneous Myiasis

Question 1

What causes Cutaneous Myiasis, and where is it commonly found?

Answer 1

Cutaneous Myiasis is caused by infestation with diptera larvae, specifically:
Tumbu fly (Cordylobia anthropophaga) in Sub-Saharan Africa
Dermatobia hominis (human botfly) in South America

Question 2

How does infestation with Tumbu fly (Cordylobia anthropophaga) occur?

Answer 2

Infestation occurs when ova are laid on wet clothing. The ovum hatches and enters the human skin when the clothes are worn, forming a small papule within 24 hours. The lesion enlarges as the larva grows and eventually emerges from the skin.

Question 3

What are the three cutaneous forms of Myiasis?

Answer 3

Furuncular form: Caused by Cordylobia anthropophaga or Dermatobia hominis larvae. It presents as small erythematous papules that enlarge into furuncles with a central punctum. Patients may feel itching, pain, or movement within the lesion.
Wound Myiasis: Caused by Cochliomyia hominivorax or Chrysomya bezziana larvae. Patients report pain, bleeding within existing wounds, fevers, chills, and may have lab abnormalities like eosinophilia or leukocytosis.
Migratory Myiasis: Caused by Hypoderma bovis or Gasterophilus intestinalis. It presents as itchy serpentine lesions similar to cutaneous larva migrans, commonly found in patients living near horses and cattle

Question 4

How is Cutaneous Myiasis clinically diagnosed?

Answer 4

Clinical diagnosis is usually sufficient.

Question 5

How is Cutaneous Myiasis clinically treated?

Answer 5

Cover suspicious abscesses with greasy ointment to suffocate and expel the larvae.
Gently remove the larvae.
Administer oral Ivermectin (single dose 200 µg/kg).
Antibiotics may be necessary if there is a superimposed infection.

Question 6

What are prevention strategies for Cutaneous Myiasis?

Answer 6

Prevention strategies include hanging wet clothes on lines in sunlight and ironing clothes to kill any ova.