All of the following are diagnostic criteria of allergic fungal sinusitis {AFS} Except ?: (A) Areas of high attuenuation on CT scan, (B) Orbital invasion, (C) Allergic eosinophilic mucin, (D) Type 1 Hypersensitivity
Answer is B. CT scan shows mucosal thickening with hyperdense areas in fungal sinusitis. Allergic fungal sinusitis is due to the type 1 hypersensitivity reaction to fungal hyphae. It presents with sinonasal polyposis and mucin. (Ref: Textbook of ENT, Diseases of ENT, Dhingra, 7th edition, pg no. 220)