Comparing Budesonide Via MAD or INSI Prospective Cohort Study

Inclusion Criteria: * Patients aged between 19 years and above * Patients with chronic or recurrent sinusitis (as defined by the American Academy of Otolaryngology) with nasal polyposis or allergic fungal rhinosinusitis * Patients with an upcoming primary sinus surgery or a revision sinus surgery * Patients being prescribed INCS for the first time following Functional Endoscopic Sinus Surgery (FESS) Exclusion Criteria: * Individuals unable to understand the purpose, methods and conduct of this study * Patients unwilling to provide informed consent * Are immuno-compromised, and have impairment in mucociliary function (e.g., cystic fibrosis, Kartagener syndrome) * Have autoimmune diseases affecting the upper airway (eg Systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis etc) * Have sinonasal tumors * Patients with a history of pituitary disease * Patients with a known hypersensitivity to cortisol, corticotropin, or cosyntropin * Recent use of systemic corticosteroids such as prednisone (within last 3 months) * Patients that are not adherent to budesonide via MAD/INSI treatment * Patients who are pregnant or breastfeeding