A Leech Inhabiting the Nasal Cavity

A 51-year-old man presented to the outpatient clinics of the Department of Internal Medicine and the Department of Otorhinolaryngology for evaluation of a suspected foreign body in his left nasal cavity (Figure 1a). For more than 2 weeks, he had experienced only occasional mild nasal itching, nasal congestion, sneezing, and minor epistaxis. Nasal endoscopy revealed a live leech, measuring approximately 2.0 × 0.5 cm, in his left nasal cavity (Figure 1b). The leech was successfully removed through nasal endoscopy (Figure 1c). The patient was a farmer who routinely drank untreated spring water and washed his face with it while working in mountain fields, which may have allowed leech larvae to enter his body through the mouth or nasal cavity and establish parasitism. He was subsequently diagnosed with Dinobdella ferox (D. ferox) parasitism. D. ferox is a species of leech that can invade the nasal cavity, throat, and other parts of the human body or animals.¹ It commonly inhabits streams and springs in humid tropical and subtropical mountainous regions, particularly in Southeast Asia.^{2, 3} After removal of the leech, the patient was treated with topical antiallergic medication. He remained free of unusual symptoms during more than 1 year of follow-up.

Figure 1.

(a) A live leech emerged from the left nasal cavity. (b) Nasal endoscopy revealing a 2.0 × 0.5-cm live leech in the left nasal cavity. (c) The extracted leech.