Recurrent respiratory papillomatosis, caused by low-risk human papilloma viruses, is a chronic disease of the upper respiratory airway. The larynx is most frequently affected organ. Many treatment modalities such as CO2 laser and cidofovir have been applied to control this disease in less invasive way. Cidifovir is an anti-viral agent and has been expected to eradicate human papilloma virus. However, this agent has not been commercially available in Japan yet. Here we report two cases of recurrent laryngeal papillomatosis were treated with topical cidofovir injection. The patients received local injection for three times in 4 weeks. The diseases have been controlled and there have been no adverse effect for 32 months and 17 months.
