Recurrent respiratory papillomatosis (RRP) occurs anywhere from the nose to the lung, but 95 percent of the cases involve the larynx, followed by the trachea, bronchi, palate, nasopharynx, and pulmonary parenchyma, in that order. The spread or growth of RRP is not uniform and varies from case to case. The papillomas either undergo spontaneous remission or persist in a stable state. It also may also spread distally down the tracheobronchial tree.
The tumor that causes RRP is mostly benign, but in three to five percent of cases, it causes squamous cell carcinoma, a deadly type of cancer with no scope for prognosis. If left unchecked, papillomas can proliferate rapidly and completely block airways, causing death.
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Recurrent respiratory papillomatosis comes from exposure to human papilloma virus (HPV), and is amongst the many human papilloma virus infections.
HPV is the most common sexually transmitted disease in the United States, and 75 percent of mothers have genital HPV, which they transmit to their offspring during the peripartum period. Children having vaginal delivery as opposed to caesarian delivery, being firstborn, or having a mother younger than 20 years are most susceptible to HPV infection
The cause for RRP in adults is not conclusive, with sexual transmission the most likely possibility.
The common symptoms of recurrent respiratory papillomatosis in adults include
- voice developing hoarseness or high-pitch
- frequent choking episodes
- sensation of a foreign body inside the throat
- frequent coughs
- dyspnea or shortness of breath
- inspiratory wheezing
The common symptoms of recurrent respiratory papillomatosis in children include
- weak cry
- episodes of choking, hoarseness
- failure to thrive or remaining bogged down
Otolaryngologists diagnose an estimated 1500 new cases of RRP every year. The disease affects two out of every 100,000 adults and 4.5 out of every 100,000 children. It mostly affects either children below five years or adults above 40 years of age. RRP being a rare disease risks misdiagnosis as asthma, croup, or chronic bronchitis.
The three most common type of diagnosis are:
- visual examination for presence of papillomas by placing a mirror at the back of the throat to reflect light down the throat.
- laryngoscopy, or insertion of a lighted tube down the throat and a fiber optic camera placed at the mouth to view the voice box, especially for young children or patients with narrowing in the throat, for whom direct visual examination may not be possible
- biopsy or removal of tissues and cells and testing them for HPV.
The recurrent respiratory papillomatosis virus is difficult to eliminate. Latent virus may remain in adjacent tissue causing recurrence of RRP even after removal of all growths. The treatment approach therefore aims at reducing papilloma to decrease the spread of disease, and thereby create a safe and patent airway and improve voice quality. Treatment remains ongoing and papilloma needs removal on a periodic basis till death.
The treatment takes any of the following approaches:
- Carbon Dioxide Laser Vaporization: The most popular method to eliminate papilloma is by angiolytic laser or microdebridement. This is an improvement of traditional endoscopic methods such as cup forceps removal, cryosurgery, and suction diathermy. Laser permits a more precise and complete removal of the papillomas, but also present risks such occurrence of airway fire, stenosis, and fistulas. An alternative approach to lasers is eradication using ultrasound.
- Tracheostomy: An alternative approach to laser and endoscopic methods is tracheostomy or surgery on the neck to open a direct airway through an incision in the trachea. This is the best option for infants less than two years of age, for whom lasers are not an option.
- Medication: Medication does not cure recurrent respiratory papillomatosis. Interferon medication, or a supplementing proteins in the immune system with synthetic versions slow the rate of growth of papillomas but does not cure the disease.
- Laryngectomy: Advanced stages of recurrent respiratory papillomatosis might require the removal of the larynx and separation of the airway from the mouth, nose, and esophagus.
Two methods still under research include adjuvant immunotherapy that attempts to augment the patient’s immune response to the viral infection and photodynamic therapy using dihematoporphyrin ether (DHE). Though results are promising, the findings are not yet conclusive.