Point-of-Care Ultrasound Findings in a Case of Botfly Myiasis Contracted in the United States

Ultrasound features of cutaneous myiasis: a rare case in a child

Cutaneous myiasis is an infestation of the skin with larvae of some dipteran species. Among humans, Dermatobia hominis is the most frequently encountered dipteran responsible for cutaneous myiasis. This insect is endemic to tropical and subtropical regions, consequently, individuals travelling from non-endemic areas are most susceptible to infection due to a lack of prior exposure. Three clinical variants of myiasis are distinguished: furuncular, migratory, and wound myiasis. Furuncular myiasis represents the most common form among travelers, yet it is a rare cause of pediatric skin manifestations in developed countries. Limited awareness of this condition in non-endemic regions contributes to diagnostic challenges. In this scenario, ultrasound is useful in the diagnostic workup, enabling the identification of the viable larva.

Twinkle Artifact Observed During POCUS of a Human Myiasis Caused by the Dermatobia hominisBotfly

An 81-year-old man presented to urgent care for assessment of an area of erythema and tenderness on his right thigh after recent travel to Belize. Point of care ultrasound (POCUS) revealed a hyperechoic structure with acoustic shadowing in the subcutaneous tissue. Colour Doppler assessment of the structure produced a twinkle artifact. The structure was removed and pathology identified the object as a Dermatobia hominis larva (human botfly). The use of POCUS helped identify and localize the subcutaneous foreign body. The use of colour Doppler produced the twinkle artifact, which has not been previously reported as a finding produced during ultrasonographic assessment of botfly larvae.