beCLomethasone Efficacy in Acute Rhinosinusitis - CLEAR Study

Inclusion Criteria: 1. Subject's written informed consent obtained prior to any study-related procedures 2. Male and female out-patients aged between 18 and 65 years (inclusive). 3. History of previously diagnosed recurrent or chronic sinusitis that necessitate antibiotic therapy as judged by the investigator. 4. Clinical diagnosis of acute rhinosinusitis defined, according to the European Position Paper on Rhinosinusitis and Nasal Polyps 2007 (20), as the sudden onset of two or more relevant symptoms for \<12 weeks, at least one of which is: * Nasal blockage/obstruction/congestion, OR * Nasal discharge (anterior/posterior nasal drip); AND the second one is: • Facial pain/pressure or/and reduction/loss of sense of smell. 5. A cooperative attitude and ability to be trained to use correctly the nebuliser with intranasal nose piece. Exclusion Criteria: 1. Previous sinus surgery; 2. Sinus lavage within the past 7 days; 3. Nasal polyposis or important nasal septum deviation; 4. Antibiotic use (by any route) in the past 30 days; 5. Recurrent moderate epistaxis; 6. Chronic bacterial sinusitis with evidence of failure of antimicrobial therapy; 7. Intranasal or systemic use of corticosteroids within the past 30 days; 8. Chronic use of corticosteroids or immunosuppressive agents; 9. Immunocompromised states; 10. Diagnosis of bronchial asthma or chronic obstructive pulmonary disease (COPD); 11. History of clinically significant cardiac (i.e. congestive heart failure or severe hypertension), renal (i.e. kidney failure), psychiatric (i.e. depression or mood disorders), hepatic (i.e. cholestatic jaundice or hepatic dysfunction), endocrine (i.e. hyperthyroidism or adrenal suppression) or pulmonary disease, or laboratory testing abnormalities, whose sequelae and/or treatments can interfere with the results or treatments of the present study; 12. History of psychiatric diseases likely to require treatment with antidepressant drugs during the study period or treatment with antidepressant drugs in the past 2 weeks; 13. Diagnosis of glaucoma or prostatic hypertrophy; 14. History of alcohol or drug abuse; 15. Allergy, sensitivity or intolerance to study drugs and/or study drugs formulations ingredients (e.g. corticosteroids); 16. Pregnant or lactating women or all women physiologically capable of becoming pregnant UNLESS they meet the following definition of post-menopausal: 12 months of natural (spontaneous) amenorrhea or 6 months of spontaneous amenorrhea with serum FSH levels \>40 mIU/mL or are using one or more of the following acceptable methods of contraception. surgical sterilization (e.g. bilateral tubal ligation, hysterectomy) hormonal contraception (implantable, patch, oral) double-barrier methods (any double combination of: IUD, male or female condom with spermicidal gel, diaphragm, sponge, cervical cap). A pregnancy test (urine) will be performed at screening in women of childbearing potential. 17. Patients unlikely to comply with the protocol or unable to understand the nature, scope and possible consequences of the study. 18. Participation in another trial in the past 12 weeks or patients previously enrolled in this study.