Conditions: Laryngeal Papillomas (Recurrent Respiratory Papillomatosis)
Noncancerous, HPV-related growths of the voice box and airway that tend to return after removal
What are laryngeal papillomas?
Recurrent respiratory papillomatosis (RRP), often called laryngeal papillomas, is a rare disease in which wart-like growths (papillomas) develop in the airway. These growths are benign, meaning they are not cancer, but they tend to come back after being removed, which is why the condition is called "recurrent." General information on papillomas in this region is also available on the papilloma of the mouth, throat, nose, and larynx page.
The growths appear most often on the voice box (larynx) and vocal cords. Less commonly, they can spread further down the airway to the windpipe (trachea), the breathing tubes of the lungs (bronchi), and rarely into the lung tissue itself. Because the papillomas grow in the airway, they can affect both the voice and breathing.
RRP is uncommon, with roughly 1 to 2 new cases per 100,000 people each year.
What causes laryngeal papillomas?
RRP is caused by infection with the human papillomavirus (HPV), the same family of viruses responsible for skin warts and other conditions. More than 200 types of HPV exist, but two types, HPV 6 and HPV 11, cause more than 90 percent of RRP cases.
These two types are considered "low-risk" because they rarely lead to cancer. HPV 11 tends to be linked with more aggressive disease than HPV 6.
How the virus is acquired depends on the age group affected:
In children, the virus is usually passed from mother to baby during pregnancy or childbirth, as the baby passes through the birth canal. This does not mean the mother did anything wrong; many people carry HPV without knowing it.
In adults, the virus is generally spread through sexual contact. In some cases, an infection acquired earlier in life may stay dormant and only cause disease later when the immune system changes.
Most people who carry HPV never develop RRP. It is not fully understood why only certain people go on to develop the growths, but differences in the immune system's response to the virus are believed to play a role.
How do laryngeal papillomas present?
Symptoms depend on how many growths there are, how large they are, and where they sit in the airway. Because the symptoms are not specific to this condition, RRP can be mistaken for more common problems such as asthma, croup, allergies, or ongoing respiratory infections. Common signs and symptoms include:
A hoarse or weak voice, voice changes, or (in infants) an abnormal-sounding cry. This is usually the earliest and most common symptom (see also voice conditions)
Noisy breathing, especially a high-pitched sound when breathing in (stridor)
Chronic cough
Shortness of breath or difficulty breathing
Wheezing
Repeated respiratory infections or pneumonia
In young children, worsening voice changes followed by noisy or labored breathing are typical. Because a child's airway is small, growths can narrow it enough to cause breathing trouble.
Juvenile-onset versus adult-onset disease
RRP is grouped by the age at which symptoms first appear:
Juvenile-onset RRP typically begins in early childhood, often between ages 2 and 5. This form tends to be more aggressive, with growths that return more often and sometimes spread more widely in the airway. Younger children may need more frequent procedures over time.
Adult-onset RRP most often appears between about 20 and 40 years of age. It is frequently, though not always, less aggressive than the childhood form.
Research suggests disease onset may cluster around several ages across the lifespan, commonly noted around ages 7, 35, and later in life, so RRP can begin in older adults as well.
How are laryngeal papillomas diagnosed?
A specialist, usually an ear, nose, and throat doctor (otolaryngologist), makes the diagnosis. Steps commonly include:
Examining the airway. A thin, flexible camera (a fiberoptic laryngoscope or endoscope) passed through the nose or mouth lets the doctor see the growths directly on the vocal cords and airway.
Taking a tissue sample (biopsy). A small piece of a growth is examined under a microscope (pathology). This is how the diagnosis is confirmed, since it distinguishes RRP from other airway conditions.
HPV testing. The tissue may be tested to identify which HPV type is present, which can help estimate how the disease may behave.
Imaging. In cases where the disease may involve the windpipe or lungs, a CT scan can show the location and extent of the growths, and a bronchoscopy (a camera passed deeper into the airway) may be used to inspect the lower airway.
What is the natural course of laryngeal papillomas?
The course of RRP is unpredictable and varies widely from person to person. Some people have mild disease with long symptom-free periods, and a small number improve on their own. Others have persistent or aggressive disease in which the growths return quickly and repeatedly.
Because the underlying virus stays in the tissue, the growths commonly grow back after being removed. Some people need only occasional treatment, while others require many procedures over the years to keep the airway open and protect the voice. Growths may come back at short intervals or after long periods of remission that can last years.
Currently there is no treatment that reliably cures the condition by clearing the virus. Management is aimed at controlling the growths, keeping the airway open, and preserving the voice. Available approaches are described on the treatments of laryngeal papillomas page.
What are the possible complications?
Most complications relate to the growths blocking the airway or to the effects of repeated treatment:
Airway obstruction. Growths can narrow the airway enough to make breathing difficult. Severe blockage is a medical emergency and, though rare, can be life-threatening, particularly in young children with small airways.
Voice problems. Growths on the vocal cords, and scarring from repeated procedures, can cause lasting hoarseness or voice changes.
Spread to the lungs. In a minority of cases, growths extend into the windpipe and lung tissue, which can lead to repeated pneumonia and more serious breathing problems.
Cancerous change (rare). In a small percentage of cases (commonly cited as roughly 3 to 7 percent), the growths can turn into a cancer called squamous cell carcinoma (see throat cancers). This risk is higher when disease involves the lungs and in people who have other risk factors such as smoking.
Impact on daily life. Ongoing voice difficulties and the need for repeated procedures can affect quality of life, including communication, work, school, and emotional well-being.
Can laryngeal papillomas be prevented?
The HPV vaccine protects against HPV types 6 and 11, the main causes of RRP. Because it prevents infection with these viruses, widespread vaccination is expected to reduce future cases of the disease.
Key points
RRP is a benign but recurring condition in which HPV causes wart-like growths in the airway, mainly on the voice box.
HPV types 6 and 11 cause the large majority of cases.
Children usually acquire the virus around birth; adults usually acquire it through sexual contact.
Hoarseness is often the first sign; breathing difficulty can develop as growths enlarge.
The course is unpredictable, growths tend to recur, and there is a small risk of cancerous change.
The HPV vaccine can help prevent the disease.