Ultrasound diagnosis of cutaneous furuncular myiasis in a nonendemic area.

Cutaneous myiasis is an uncommon diagnosis in nonendemic regions and may be overlooked in returning travelers with nonspecific dermatologic complaints. We present a case of cutaneous furuncular myiasis in a 14-year-old female who presented to the emergency department with a neck mass 3 months after returning from Costa Rica after failed treatment with antibiotics and ivermectin. Ultrasonography showed an ovoid structure with a hyperechoic core with visible segmentations and surrounding hypoechoic rim; dynamic movement of the larva was not observed. Color Doppler demonstrated flow within the structure itself and in the surrounding subcutaneous tissue. CT was obtained as an adjunct to ultrasonography to examine the extent of regional inflammation and the larva's relationship to adjacent vascular and deep soft-tissue structures. This case highlights the role of targeted ultrasound in the identification of cutaneous myiasis in a nonendemic, emergency setting, to help avoid misclassification and treatment delay.