A Rare Encounter: Locally Acquired Furuncular Myiasis (Botfly) in Ohio

Background

Furuncular myiasis is a rare parasitic infestation caused by fly larvae in the skin, typically presenting as painful, inflammatory nodules. In the United States, the most common causative agent is Dermatobia hominis (human botfly), though autochthonous cases are exceedingly rare. These are caused by the rodent botfly Cuterebra, which is endemic to North America. Humans are incidental hosts, often through outdoor activities near rodent burrows. Diagnosis can be challenging, as it may resemble more common conditions such as an abscess or cellulitis.

Case Report

A 28-year-old female presented to the emergency department with swelling, erythema, and intermittent pain in the left cheek, following a suspected insect bite during a camping trip in Northeast Ohio. Despite treatment for a suspected abscess, the lesion worsened, and the patient reported movement under the skin. Ultrasound confirmed a 2cm larva with spicules, consistent with furuncular myiasis. The larva was successfully removed via a small incision under local anesthesia. Postprocedure, the wound was cleaned, sutured, and dressed, and the patient was discharged with antibiotics and follow-up instructions.

Why Should an Emergency Physician Be Aware of This?

Furuncular myiasis, though rare in the U.S., should be considered when a patient presents with a slow-growing nodule following outdoor activities. Diagnosis can be made quickly using point-of-care ultrasound (POCUS), which can differentiate myiasis from common soft tissue infections like abscesses. Early identification enables appropriate management and prevents unnecessary interventions, such as prolonged antibiotic therapy. Emergency physicians should be aware of this rare but significant condition, especially in patients with a history of outdoor exposure or travel to Central or South America.