ABSTRACT
Fungal rhinosinusitis occurs as either tissue-invasive or tissue-noninvasive disease. There are three types of invasive and two types of noninvasive disease (Table 1). The various types of fungal rhinosinusitis are distinguishable histopathologically and clinically. Allergic fungal rhinosinusitis (AFRS), also known as allergic fungal sinusitis, is a distinct type of noninvasive fungal rhinosinusitis that represents more of an allergic/hypersensitivity response to the presence of small numbers of extramucosal fungi living within the sinus cavity(s) rather than a fungal infection per se. The fungi are found growing within a characteristic extramucosal peanutbuttery mucus inspissate of many compressed pyknotic eosinophils along with their degranulation products, known as allergic mucin (1-4). AFRS is analogous in many ways to allergic bronchopulmonary aspergillosis (ABPA), a hypersensitivity disease of the lung (2,4-5,8).
