ALLERGIC FUNGAL SINUSITIS - ALLERGIC, INFECTIOUS, OR BOTH

Allergic fungal sinusitis is a benign noninvasive sinus disease relate d to a hypersensitivity reaction to fungal antigens. A wide variety of fungal agents has been implicated, with the vast majority belonging t o the Dematiaceae family. Allergic fungal sinusitis should be suspecte d in any atopic patient with refractory nasal polyps. Sinus computed t omograms and magnetic resonance imaging findings can be quite distinct ive, but not diagnostic, Diagnosis requires histopathologic examinatio n, which shows characteristic allergic mucin. Hyphae can be demonstrat ed on special fungal stains or confirmed by a positive fungal culture. At surgery, the diagnosis should be considered if thick, tenacious al lergic mucln is encountered in the atopic patient with nasal polyps. F ungal cultures should then be obtained, and the pathologist alerted to the possible diagnosis of allergic fungal sinusitus. Current recommen dations for therapy include conservative but complete exenteration of all allergic mucin. This can often be accomplished endoscopically. Adj unctive short-term systemic steroids are often helpful, and nasal ster oid sprays should be continued long term. The length and dose of stero id therapy is controversial. Persistence of allergic fungal sinusitis with recurrence of sinonasal symptoms is common, particularly when the re has been incomplete eradication of allergic fungal mucin. Even when the patient is clinically disease free, recurrence can occur, presuma bly from reexposure to fungal antigens. Therefore close clinical, endo scopic, and radiographic follow-up is important.