1. Introduction
Chronic rhinosinusitis (CRS) is a common disease with significant impact
on the patients’ health and the societal economy 1,2.
Chronic rhinosinusitis is generally categorized into two major subtypes
based upon phenotypic appearance: CRS without nasal polyps (CRSsNP) and
CRS with nasal polyps (CRSwNP). Nasal polyps (NP) are benign
inflammatory masses in the mucosa of the nose and paranasal sinuses1–3. CRSwNP is associated with morbidity and
decreased quality of life 4.
CRSwNP is estimated to affect 1–4% of the general population and
25–30% of patients with CRS (Stevens, Schleimer and Kern, 2016;
Fokkens et al., 2020). Yet, there is a paucity of prevalence data on
CRSwNP across many geographic areas 2,5,6. Based on a
few studies, the NP prevalence estimates in the Nordic countries range
from 2.7% in Sweden to 4.3% in Finland, based on single municipality
studies 7,8. Subsequently, updated population-based
data on the prevalence and incidence of CRSwNP is required.
Epidemiological, clinical, and pathophysiological studies suggest that
asthma is strongly associated with CRSwNP 9,10.
Inflammation in the nasal mucosa and lower airways are directly related,
with a correlation between the inflammatory profiles of nasal and
bronchial biopsies in patients with CRSwNP 11. It has
been reported that up to 45% of CRSwNP patients have or will develop
asthma 9,12. The prevalence of CRSwNP is higher in
patients with asthma (7%) compared to the general population (4%)13. However, in the Finnish asthma population, the
prevalence of NP has been shown to be as high as 16.5%7.
The mainstay therapy of CRSwNP includes medical treatments such as nasal
or oral corticosteroids. For patients with CRSwNP who do not respond to
conservative therapy, endoscopic sinus surgery (ESS) is considered.
CRSwNP patients have been demonstrated to benefit from ESS, although a
part of the CRSwNP patients have polyp regrowth and a need for a
revision ESS as signs of uncontrolled disease 14–17.
Among Finnish patients treated with functional endoscopic sinus surgery
(FESS), the prevalence of CRSwNP as the primary diagnosis has been
reported to be 17% 18.
A limited number of studies indicate that both medical interventions and
FESS improve nasal outcomes in patients with CRS and asthma,19,20 but, more information is needed about the burden
of CRS and how it is affected by concomitant asthma.
The aim of this nation-wide
real-world study was to evaluate prevalence and incidence of CRSwNP in
Finland, and to describe treatment burden of CRSwNP and how this is
related to the presence and severity of co-morbid asthma.