Recurrent respiratory papillomatosis (RRP) is a rare viral disease where tumors (papillomas) grow in the air passages leading from the nose and mouth into the lungs (respiratory tract). There are two types, a juvenile-onset form and an adult-onset form. The tumors can cause a hoarse voice, chronic cough, and difficulty breathing. They may vary in size and grow very quickly, and may grow back even when removed. These tumors rarely become cancerous, but can cause long-term airway and voice complications. RRP is caused by two types of human papillomavirus (HPV), called HPV 6 and HPV 11. It is transmitted from an infected mother to her baby through the placenta or through the birth canal. HPV can also be transmitted from one adult to another through oral sex. The HPV vaccine can help prevent infection.