Cutaneous myiasis from Panama, South America: case report and review

Myiasis is a cutaneous infestation with larvae of Diptera, the two-winged arthropod order. Eggs and/or larvae are transmitted directly from the environment or via arthropod vectors. Larvae are able to burrow into the dermis of intact skin or external body orifices. Three clinical variants of myiasis are furuncular, migratory (creeping), and infestation of wounds.

A 35-year-old male presented with a 1-month history of worsening furuncles on the left knee and posterior thigh following his return from Panama, South America. Clinical examination revealed tender 6 cm and 2 cm erythematous to violaceous furuncles with surrounding desquamation and central puncta draining serosanguinous fluid. Five-millimeter punch biopsies and tissue swabs were performed.

All larvae were of the Dermatobia hominis species. The patient was empirically treated with cephalexin and ciprofloxacin for secondary bacterial cellulitis. Tissue swabs later cultured group B streptococcus. A tetanus booster was recommended.

This case report describes a relatively rare cutaneous infestation with D. hominis, a Central and South American endemic larva of the human botfly. Increasing trends toward immigration and global travel to tropical and subtropic areas will likely increase the frequency of encounters with such parasitic cutaneous infestations in North American outpatient dermatology clinics.