Allergic fungal rhinosinusitis: pathophysiology, epidemiology, and diagnosis

Allergic fungal rhinosinusitis (AFRS) is believed to have a cause similar to allergic bronchopulmonary aspergillosis (ABPA). Both are thought to be mediated by both type I (IgE) and type III (IgE-antigen immune complexes) Gell and Coombs reactions. ABPA patients also exhibit unique characteristics, such as HLA-DR2 or HLA-DR5 genotypes, and elevated suppressor T cell activity. While the pathophysiology of AFRS is similar histopathologically, similar immunologic studies have not been as well documented. Most cases of AFRS involve dematiaceous fungi, rather than Aspergillus. A suggested laboratory work-up for the disease is presented.