Nasal Polyps

Etiology

Nasal polyps are benign pedunculated tumors formed from edematous, usually chronically inflamed nasal mucosa. They commonly arise from the ethmoidal sinus and occur in the middle meatus. Occasionally they appear within the maxillary antrum and can extend to the nasopharynx (antrochoanal polyp).

It is estimated that between 1% and 4% of the population will develop nasal polyps at some point; the incidence of nasal polyps increases with age. Antrochoanal polyps represent only 4–6% of all nasal polyps in the general population but account for approximately one third of polyps in the pediatric population. Large or multiple polyps can completely obstruct the nasal passage. The polyps originating from the ethmoidal sinus are usually smaller and multiple, as compared with the large and usually single antrochoanal polyp.

Cystic fibrosis (CF; see Chapter 432 ) is the most common childhood cause of nasal polyposis, and up to 50% of CF patients experience obstructing nasal polyposis, which is rare in non-CF children. Therefore, CF should be suspected in any child younger than 12 yr old with nasal polyps, even in the absence of typical respiratory and digestive symptoms. Nasal polyposis is also associated with chronic sinusitis (see Chapter 408 ) and allergic rhinitis. Large population studies have noted a significant familial risk in having chronic rhinosinusitis with polyposis. Furthermore, it has been noted in a substantial number of studies that low vitamin D levels are correlated with polypoid chronic rhinosinusitis, likely related to the role vitamin D plays as an immunomodulator in the respiratory epithelium. In the Samter triad , nasal polyps are associated with aspirin sensitivity and asthma; this condition is rare in children.