Botfly Myiasis Masquerading as Dacryocystitis.

Cutaneous myiasis is an infection most commonly caused globally by Dermatobia hominus, the human botfly, which is endemic to Central and South America. In North America, the most common cause of cutaneous myiasis is infestation with the larvae of Cuterebra, the North American botfly. The authors describe a 44-year-old man who presented with a 1-month history of intermittent, severe, boring pain along the side of his nose that progressed to swelling and redness along his right inferior orbital rim and lacrimal sac. CT imaging showed a rim-enhancing collection at the right medial canthus with surrounding phlegmonous changes communicating with the skin. Pathologic evaluation revealed curvilinear pigmented material associated with a granulomatous and eosinophil-rich inflammatory infiltrate, consistent with botfly myiasis. This case describes the pathogenesis of the botfly infestation in humans, as well as the clinical, radiographic, and histopathologic features of this rare orbital infection, with an emphasis on its treatment.