Allergic Fungal Rhinosinusitis (AFRS) is a severe sinus infection causing mucus and polyps that block breathing. This study tests Dupilumab, a medicine that might help after endoscopic sinus surgery. Eligible participants are adults (18+) with AFRS undergoing surgery. Before surgery, participants will have scans and exams, including a camera exam of their sinuses. During surgery, nasal tissue will be collected for research.

After surgery, participants will receive injections at home every two weeks for a year. Some will get Dupilumab, while others will get a placebo (a shot with no medicine). They won't know which one they receive. Participants will have a clinic visit 16 weeks after surgery and follow-up for 12 weeks after treatment ends.

• The study lasts over one year, with regular injections and follow-ups.
• Participants must self-administer injections every two weeks.
• Participants will not know if they are receiving the real drug or placebo.