Description
Allergic fungal sinusitis (AFS) is characterised by allergic mucin that is firm and lamellated and contains abundant eosinophils, respiratory epithelial cells, Charcot-Leyden crystals and sparse fungal hyphae. Fungi occur exclusively within the mucin without tissue invasion. Patients are immunocompetent, atopic, often with asthma, have nasal polyposis and a characteristic computed tomography scan. A broad variety of fungi have been identified. AFS is believed to be due to a combination of IgE-mediated (type-I) and antibody-antigen (type-III) hypersensitivity reactions to the specific fungal antigens. It should be distinguished from other fungal infections of the nose and paranasal sinuses.
