Viral, non-cancerous warts called papillomas develop on the surfaces of the respiratory tract; most cases of RRP involve the voice box, or larynx. Occasionally, papillomas will grow in the mouth or windpipe and, in rare cases, the lungs. There are two types of RRP: adult onset and juvenile onset.
Even though papillomas are not cancerous, they are dangerous because their presence in the airway can make breathing difficult. Growth of papillomas can cause severe, sometimes life-threatening airway obstruction. After removal, papillomas tend to regrow because the virus persists in the tissue even after the growths are removed. It is important to have frequent examinations to keep the papillomas at a manageable level. While they are noncancerous, some very rare cases can become cancerous.
RRP is caused by HPV. Between 75 and 80 percent of people will be infected by HPV during their lifetime if not vaccinated against the virus. Many people infected with HPV may never develop symptoms. HPV is transmitted through genital contact, not through casual contact. It is not well understood why some people who have been exposed to the virus develop RRP and others do not.
Two specific HPV subtypes are responsible for more than 90 percent of cases of RRP: HPV 6 and HPV 11. Type 11 appears to be more aggressive and associated with airway obstruction and spreading to the lungs. Adult onset recurrent respiratory papillomatosis (AORRP) develops in the fourth decade of life whereas juvenile onset recurrent respiratory papillomatosis (JORRP) develops before age five. JORRP is more common and more severe than AORRP.
In children, HPV is likely transferred from an affected mother to the child during labor. However, C-sections do not appear to have a protective effect. Risk factors for JORRP include being a first-born child, having a vaginal delivery or prolonged labor, and the mother being under 20 years of age. In adults, less is known about the mode of transmission. Some patients are infected during infancy, but the disease may not develop until adulthood. Some evidence suggests that RRP can develop after HPV is transmitted through oral sexual contact. AORRP is worsened by tobacco use, gastroesophageal reflux disease (GERD), and radiation therapy.
Currently, there is no “cure” for RRP. The size and location of the lesions helps the treatment team decide which approach is best for each patient. The goals for treatment are to remove the papillomas, create an open airway, improve voice quality, and increase the time between surgical procedures. RRP is diagnosed by examining the upper airway by an ENT (ear, nose, and throat) specialist, or otolaryngologist, during an office visit using a camera that is inserted through the nose or mouth. Once noted, diagnosis is confirmed by biopsy.
RRP is treated with surgery to remove the benign growths from the airway without damaging the underlying tissue or organs. This is usually performed in the operating room under general anesthesia. Some patients may require surgery every few weeks while others may only require surgery twice a year or a few times during their life. Surgical techniques used to remove RRP lesions include cold excision, microdebridement, and laser removal. Cold excision is the use of sharp surgical equipment to remove papillomas. Microdebridement involves suctioning the affected area, which is then cut away by a fast-rotating blade or shaver. Laser ablation uses a CO2 laser to directly destroy the papillomas in the airway.
Certain medications, including interferon, indole-3-carbinol, and cidofovir®, may be recommended to try to reduce the rate of papilloma regrowth, thereby increasing the time between necessary surgeries. Interferon is a synthetic form of certain proteins produced by the immune system, but because of its adverse effects, it is a second-line therapy for patients with hard-to-manage severe diseases. Indole-3-carbinol is a compound found in cruciferous vegetables such as cabbage, cauliflower, and broccoli, and has been shown to slow papilloma growth.
The most common antiviral medication used in patients with RRP is cidofovir. This drug is injected into the papilloma to slow the regrowth and increase the time between therapies. Initial studies of cidofovir indicate that it’s active against RRP and may lead to a partial response in some patients and complete remission in others. However, cidofovir may also cause several side effects and has a small potential for causing the papillomas to become cancerous.
Additional drugs are being studied as potential therapies for patients with RRP, including the monoclonal antibody bevacizumab. Bevacizumab has been shown to be effective when administered intravenously after surgical removal of papillomas. This form of treatment seems especially helpful in patients with rapidly recurring papillomas in the larynx and trachea.
In some severe cases, where tumor growth is aggressive, a patient may need a tracheostomy to keep the airway open. A tracheostomy involves surgically inserting a tube into the windpipe through the front of the neck. A tracheostomy is only used as a method of last resort because the procedure may allow for the spread of disease further into the respiratory tract.
An HPV vaccine, Gardasil-9®, has been developed to protect women from developing HPV-related cancers such as cervical cancer, men from developing penile cancer, and both men and women from developing genital warts and certain cancers of the head and neck. Among the subtypes of HPV covered by the vaccine are HPV 6 and HPV 11, those that cause RRP. The use of the Gardisil-9 vaccine in children before they are exposed to the virus will drastically lessen the spread of HPV in the general population. Unfortunately, this type of vaccine does not make existing infections go away.
Last reviewed February 2022.
The head and neck include some of our body’s most vital organs, which can be especially susceptible to tumors and cancer. In addition to cancers of the head and neck, ENT specialists treat neck masses, Grave’s disease, and more.
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