A case of cutaneous myiasis due to Dermatobia hominis in Japan

We report the 34th imported case of cutaneous myiasis caused by Dermatobia hominis in Japan, which is not a habitat of the fly. A 41-year-old Japanese man noticed an insect-sting-like papule on his left upper back during his stay in Ecuador in March 2004. After his return home, the lesion gradually increased to become a red subcutaneous nodule with a central pore from which serosanguineous fluid drained. Because antimicrobial treatment under a diagnosis of inflammatory atheroma was ineffective, the lesion was incised and a 3rd instar larva of D. hominis was then found and removed. We checked the literature on D. hominis myiasis reported from Japan, and noted the fact, which nobody had previously pointed out, that in Japan only one case of D. hominis myiasis had been diagnosed correctly before a larva was found, and most of the cases were misdiagnosed and inappropriately treated, including 11 cases given unnecessary resection of the nodules. Doctors in Japan should be aware of myiasis so that patients are neither anxious about the disease nor suffer pain, and doctors avoid performing unnecessary resections of the lesions.