[A case report of nasal infestation by the leech, Dinobdella ferox].

A 55-year-old man in Okagaki Town, Fukuoka Prefecture, pulled a nasal leech from his nostril in July 1987, after suffering from nosebleed, copious running snivels as well as unpleasant foreign body sensation in the nasal cavity. Except for nasal septum deviation, no abnormality in the ears and mouth cavity nor bleeding, ulcerous and erosive changes in the nasal cavity were found. The formalin-fixed specimen of the leech was nearly black with no definite stripes or spots, and measured 3.5 cm in length and 1.2 cm in width. Because of these and the following characteristics, viz. 1) auricles on the posterior segment were absent, 2) five pairs of eyes were present in the anterior segments with the eye pairs 3 and 4 separated by an annulus, and 3) teeth were not observed, this specimen was identified as Dinobdella ferox. This nasal leech is found widely in Southeast Asia. In Japan, some human cases of its infestation have also been reported, mainly from southern Kyushu. The leech seemed to have entered the nasal passage of the present case from a stream at a hot spring in northern Kyushu. Attention should be given to nasal leech infestation especially now that many people in Japan are eager to visit isolated hot spring resorts.