Rhinosinusitis Italian Network: the Italian Registry for Severe, Uncontrolled Chronic Rhinosinusitis

Inclusion Criteria: * Participants with a confirmed diagnosis of bilateral Chronic Rhinosinusitis that have at least three (in case of patients previously treated with surgical approaches) or four (in case of patients never treated with nasal sinus surgery) of the following criteria: * Evidence of type 2 inflammation (at least 250 blood eosinophils per microliter and / or at least 10 eosinophils / HPF from a histological sample of sinus mucosa and / or at least one finding of moderate eosinophilia on nasal cytology and / or total serum IgE \>100 IU / ml); * at least two Short courses of systemic corticosteroids or lorg-term Systemic Corticosteroids therapy for Chronic Rhinosinusitis; * Significant deterioration in the quality of life (Sinonasal Outcome Test 22 - SNOT-22\>= 40 and / or Visual Analogue Scale - Global VAS of symptoms\>= 5); * Loss of Smell (VAS for hyposmia\> = 7) Exclusion Criteria: \-