Fungal Rhinosinusitis

Abstract

Rhinosinusitis is the inflammation of nose and sinuses. In the disease process, the inflamed and swelled mucous membrane of nose and paranasal sinuses obstructs the sinus opening and prevents mucous from draining normally, leading to pain, nasal blockade, swelling, fetid discharge. The course of the disease may be acute or chronic depending on the etiological agents and host immunity. Fungus as a cause of rhinosinusitis has gained importance in last two decades. It may cause rhinosinusitis either by allergic inflammatory process or by direct infection. Fungal rhinosinusitis (FRS) is common in Asian countries especially India, Pakistan, and Saudi Arabia [1–8]. The disease may be prevalent in other Asian countries, but the prevalence is not known due to the absence of studies. In a study in the villages of North India, it was observed that 1.4% of young adults suffer from chronic rhinosinusitis (CRS). The prevalence of FRS was 0.11% of population and 8.1% of all CRS cases [9]. A great deal of controversy exists regarding etiology and pathogenesis of CRS. The claims of scientists range from fungi are only bystanders to all CRS cases are due to fungi [2, 3]. Attempts have been made by researchers to resolve the controversy, as therapy varies in different categories of rhinosinusitis. CRS affects nearly 20% of population at some time in their lives [3, 10, 11]. Scientists broadly classify FRS into invasive and noninvasive diseases depending on the invasion of nasal and paranasal sinus tissues by fungi. Depending on the immune status and histopathology, invasive disease is further differentiated into acute invasive, granulomatous invasive, and chronic invasive type. The noninvasive FRS is described in four different clinical forms: localized colonization, fungal ball, allergic fungal rhinosinusitis (AFRS), and eosinophilic fungal rhinosinusitis (EFRS) [2, 3, 12]. The descriptions of all these entities are summarized in Table 11.1. In Asian countries the common clinical form are AFRS, EFRS, and granulomatous invasive types in immunocompetent hosts [1–8].