Allergic fungal rhinosinusitis (AFRS) is a distinct subtype of chronic rhinosinusitis with nasal polyps (CRSwNP). It is characterized by a disease with non-invasive fungal hyphae, which causes immunoglobulin E (IgE)-mediated mucosal hypersensitivity resulting in the formation of eosinophilic mucin. Unlike other subtypes of CRSwNP, studies showed that the IgE level is very high in AFRS.
Allergic fungal rhinosinusitis requires surgical debridement (removing damaged tissue) along with medical therapy. Many patients can have AFRS recurrence post-surgery, so the patients should use topical steroids.
Dupilumab has been able to treat chronic rhinosinusitis with nasal polyps (CRSwNP) and should be able to treat AFRS, but it is under the Dupilumab Development Program (a program where two companies Sanofi and Regeneron are studying dupilumab and how it can reduce type 2 inflammatory diseases like topic dermatitis, asthma, CRSwNP, etc).