Efficacy of Nasal Irrigation With Respimer® Netiflow® vs Saline Among Patients With Cystic Fibrosis and Chronic Rhinosinusitis

Inclusion Criteria: * • Patient with Cystic Fibrosis with or without lung transplant; * Patients with allergic chronic rhino sinusitis or no allergic diagnosed by the clinical investigator on the basis of the following signs in variable combination: nasal congestion, headache, sneezing, itchy nose and eyes, runny nose, nosebleeds and nasal crusts, redness and eye discharge present more than 3 months per year. * Patient treated on an outpatient basis; * Patient agreeing not to take sea baths for the duration of the study; * Patient agreeing to respect the procedures for conducting the study, in particular the washout period and follow-up visits; * Patient capable of understanding and self-completing the questionnaires; * For juvenile patients, the holder (s) of parental authority have accepted the participation of the young person (by signing the informed consent after having taken note of the information note) * Member or beneficiary of a social security program Exclusion Criteria: * Patients with significant obstruction of the nasal passages due to: * a mucocele, * polyposis causing nasal obstruction\> 90% or * severe malformation of the septum causing a nasal obstruction\> 90% in whom surgical treatment is recommended; * Patients with signs of severity that may require hospitalization, such as: severe impairment of general health, dyspnoea with cyanosis, high fever (\> 40 ° C). * Patients requiring corticosteroid therapy during the study, with the exception of patients who received pulmonary transplant and were treated with oral corticosteroids at no more than 0.2 mg / kg / day. * Patients with known systemic immunodeficiency status with the exception of patients receiving pulmonary transplantation and immunosuppressed. * Patient pregnant (urine test) or without effective contraception (birth control pill, contraceptive patch, contraceptive implant, vaginal ring, intrauterine device or intrauterine device, male condom). * Nursing patient. * Patient with a contraindication to nasal irrigations as defined in the product leaflet.