Nasal polyposis, occurring in about 2% of the general population, is the ultimate form of
inflammation of the upper airways. For unknown reasons,
polyps develop preferentially in subtypes of inflammatory diseases and are associated with perennial non-
allergic rhinitis,
asthma, intolerance of
aspirin (
acetylsalicylic acid)/
NSAIDs,
allergic fungal rhinosinusitis,
cystic fibrosis, and
primary ciliary dyskinesia. In contrast to common beliefs,
IgE-mediated
allergy does not seem to play an etiological role in nasal polyposis.The
polyps originate from the mucosa around the clefts of the lateral nasal wall, especially in the region of the ostiomeatal complex. The factors that determine the localization of the disease to a few square centimeters of the airways are not known.Polyps are edematous bags covered by respiratory epithelium and contain very few nerves, blood vessels, and glands that have undergone cystic degeneration. They contain degranulated mast cells, have a very high concentration of
histamine, and are characteristically infiltrated by eosinophils. These cells accumulate due to the release of proinflammatory
cytokines (in particular,
interleukin-5).Nasal polyposis is preceded by a prolonged history of
rhinitis accompanied by severe and persistent
nasal blockage; typically, the sense of smell is seriously impaired when
polyps develop. The diagnosis is based on anterior rhinoscopy or, preferably, endoscopy.Nasal polyposis is medically treatable. Surgical treatment is carried out when medication fails. Intranasal
corticosteroids reduce
rhinitis symptoms, improve nasal breathing, reduce the size of
polyps, and prevent, in part, their recurrence, but this treatment has little effect on the sense of smell. Intranasal
corticosteroids can, as basic long-term
therapy, be used alone in mild cases or together with systemic
corticosteroids and/or surgery in severe cases. Systemic
corticosteroids administered for 2-3 weeks have a beneficial effect on all observed symptoms and pathology, including the sense of smell. When
nasal blockage is a problem in spite of medical treatment, surgery is recommended. Simple polypectomy can be performed, but endoscopic surgery is recommended in more severe and persistent cases.