Chronic Rhinosinusitis in Patients with Cystic Fibrosis

Chronic rhinosinusitis (CRS) is highly prevalent in patients with cystic fibrosis (CF) and accounts for significant morbidity and contribution to CF lung disease. Mutations of the cystic fibrosis transmembrane regulator gene occur with increased prevalence in patients with CRS without CF, suggesting some contribution to CRS pathophysiology. Nasal polyps (NPs) occur with increased prevalence in patients with CF of all ages and have a more neutrophilic appearance with fewer eosinophils and increased submucosal glandular elements in comparison to NPs from patients without CF. Mainstays of medical treatment include isotonic saline irrigations and topical intranasal glucocorticoids, with some evidence that topical intranasal glucocorticoids reduce NP size. Although inhaled hypertonic saline (7%) has been widely studied as a mucolytic agent for CF lung disease, there are no reports of its use in CF CRS. Mucolytics have also not been studied as a treatment for CRS in CF, and most evidence does not support their use for CF lung disease. Nasally nebulized dornase alfa (recombinant human deoxyribonuclease) following sinus surgery shows promise for treatment. Other unproven therapies include addition of baby shampoo to isotonic saline to potentially thin mucus and help prevent biofilm formation. There are no data to support the use of low-dose oral macrolide antibiotics or the use of prophylactic oral antibiotics for CRS in patients with CF. However, there is some support for the use of topical antibiotics, including colistimethate sodium or tobramycin, administered as a sinus irrigation or antral lavage in patients following sinus surgery when susceptible bacteria are cultured. Key components of CF sinus surgical management include extensive surgery to ensure that the maxillary, frontal, sphenoid, and ethmoid sinuses are all widely opened with smoothing of bony overhangs to prevent mucus retention and bacterial recolonization, postoperative meticulous daily nasal irrigations, and appropriate use of culture-directed topical antibiotics. There are no data yet on whether CF-targeted therapies, including ivacaftor or ivacaftor combined with lumacaftor, have an impact on CF CRS.