IGHE and nasal cavity polyp: If CRS is suspected:1.Assess disease history (all clinical settings including comorbidities)2.Perform a simple nasal inspection to rule out or confirm obvious nasal polyps (all clinical settings) and then refer to specialist care3.Perform a nasal endoscopy (specialist setting only)4.Initiate a sinus CT scan (if nasal endoscopy is unavailable, or findings are inconclusive; specialist setting only)5.Assess inflammation with serum IgE, and blood and tissue eosinophils