Clinicopathological and mycological spectrum of allergic fungal sinusitis in South India

The Impact of Climatic, Socioeconomic, and Geographic Factors on the Prevalence of Allergic Fungal Rhinosinusitis: A Worldwide Ecological Study

BACKGROUND

The prevalence of allergic fungal rhinosinusitis (AFRS) and its associated risk factors have been an issue of debate. Some epidemiological factors have been correlated to the disease prevalence.

OBJECTIVES

To observe the prevalence pattern of AFRS worldwide and to investigate the effect of specific epidemiological factors on the disease prevalence.

METHODS

A systematic review was derived from 1983 to December 2018. Data on the prevalence of AFRS were collected from the selected studies. Relevant factors assessing each city's climate, socioeconomics and geography were used to study the association with AFRS prevalence.

RESULTS

35 cities across 5 continents were investigated. The worldwide average rate of AFRS in CRS cases is 7.8% (0.2%-26.7%) in which more than half of the investigated cities (57%) had low AFRS prevalence, while the remaining cities had intermediate (11%) and high (32%) prevalence. Cities with higher temperatures were associated with a higher prevalence of AFRS (p-value 0.002), whereas cities with humid continental climate were significantly associated with a low prevalence of AFRS (p-value 0.032). Humidity and wind speed were lower in the cities with higher AFRS prevalence (p-value 0.018 and 0.008, respectively). There were no significant correlations between AFRS prevalence and economic levels, presence of water bodies, rainfall amounts, altitude, and presence of forests.

CONCLUSION

AFRS has a worldwide distribution pattern with varying prevalence. In this ecological study, we observed a correlation between AFRS prevalence and climatic factors (climate classification, humidity, temperature, and wind speed). Socioeconomic factors should be analyzed on an individual basis for better assessment of the relationship with disease prevalence.

Allergic Fungal Rhinosinusitis in Saudi Arabia: A Review of Recent Literature

Allergic fungal rhinosinusitis (AFRS) has been considered an enigma since it was first described four decades ago. Previous research has found that AFRS has multiple definitions and a poorly understood pathogenesis because it overlaps with other conditions and necessitates meticulous work and multiple diagnostic modalities to confirm the diagnosis. However, despite the expansion of medical and surgical treatments, recurrence still occurs. In this review, the recent literature on AFRS cases in Saudi Arabia with relevance to its epidemiology, diagnosis, and management was studied and compared with international data. PubMed, Google Scholar, and Cochrane Library were searched for original research and review articles with local data. There is an evident paucity and contradiction between local studies regarding the epidemiology, diagnostic methods, and management of AFRS. Hence, well-defined randomized controlled trials (RCTs) are needed for the treatment of this chronic recurrent disease.

An overview of possible pathogenesis mechanisms of Alternaria alternata in chronic rhinosinusitis and nasal polyposis

Chronic Rhinosinusitis (CRS) is a multifactorial disease, and different etiologies like metabolism and immunity disorders, bacterial superantigens, biofilms, and fungal allergens are known to develop this disease, especially the CRS with nasal polyps. Alternaria alternata (Alternaria) is one of the most prevalent airborne fungal species in the nasal discharge, which might have vigorous immunologic activities in nasal epithelial cells and play an essential role in the pathogenesis of CRS. Moreover, the interaction between this fungus and the innate and adaptive immune systems leads to the development of chronic inflammation. This inflammation may consequently instigate the CRS and nasal polyposis. The attenuation of surfactant protein synthesis or intracellular reserves and mucus hypersecretion could prevent the clearance of Alternaria from sinuses and may be correlated with colonization and re-infection of airborne fungi. Furthermore, higher expression of cathelicidin, thymic stromal lymphopoietin, toll-like receptors, and T helper 2-dominant immune responses can result in an IgE-mediated pathway activation and eosinophils degranulation. Moreover, higher local Alternaria-specific IgE was shown to be correlated with eosinophilic cationic proteins and might relate to nasal polyps. However, the role of genetic and environmental factors affecting CRS and nasal polyposis is not well studied. Likewise, further animal and clinical studies are required to better understand the role of Alternaria in CRS disease. The current article reviews the recent findings around the Alternaria-induced CRS and nasal polyposis.

Allergic Aspergillus Rhinosinusitis

Allergic fungal rhinosinusitis (AFRS) is a unique variety of chronic polypoid rhinosinusitis usually in atopic individuals, characterized by presence of eosinophilic mucin and fungal hyphae in paranasal sinuses without invasion into surrounding mucosa. It has emerged as an important disease involving a large population across the world with geographic variation in incidence and epidemiology. The disease is surrounded by controversies regarding its definition and etiopathogenesis. A working group on "Fungal Sinusitis" under the International Society for Human and Animal Mycology (ISHAM) addressed some of those issues, but many questions remain unanswered. The descriptions of "eosinophilic fungal rhinosinusitis" (EFRS), "eosinophilic mucin rhinosinusitis" (EMRS) and mucosal invasion by hyphae in few patients have increased the problem to delineate the disease. Various hypotheses exist for etiopathogenesis of AFRS with considerable overlap, though recent extensive studies have made certain in depth understanding. The diagnosis of AFRS is a multi-disciplinary approach including the imaging, histopathology, mycology and immunological investigations. Though there is no uniform management protocol for AFRS, surgical clearing of the sinuses with steroid therapy are commonly practiced. The role of antifungal agents, leukotriene antagonists and immunomodulators is still questionable. The present review covers the controversies, recent advances in pathogenesis, diagnosis, and management of AFRS.

Trichosporon inkin, an unusual agent of fungal sinusitis: a report from south India

The aetiology of fungal sinusitis is diverse and changing. Aspergillus species has been the most common cause for fungal sinusitis, especially in dry and hot regions like India. Trichosporon species as a cause for fungal sinusitis has been very rarely reported the world over. Here, we report a rare case of allergic fungal sinusitis caused by Trichosporon inkin in a 28-year-old immunocompetent woman. Bilateral nasal obstruction, nasal discharge and loss of smell were her presenting complaints. Diagnostic nasal endoscopy showed bilateral multiple polyps. Functional endoscopic sinus surgery was performed and many polyps were removed. Based on mycological and histopathological studies, the pathogen was identified as T. inkin.

Comparative study of orbital involvement in invasive and non-invasive fungal sinusitis

OBJECTIVE

To investigate differences in orbital involvement in patients with invasive versus non-invasive fungal sinusitis.

METHOD

One hundred consecutive cases of fungal sinusitis were assessed clinically and by computed tomography scan to evaluate orbital involvement.

RESULTS

Clinical orbital involvement was more common in invasive (73.5 per cent) than non-invasive (12.1 per cent) fungal sinusitis (p = 0.000). Computed tomography scanning showed similar orbital involvement in both groups, except for erosion of the floor of the orbit, which was more common in patients with invasive fungal sinusitis (p = 0.01). Extra-ocular muscle enlargement (44.4 vs 4 per cent, p = 0.01) and optic atrophy (44.4 vs 0 per cent, p = 0.003) were more common in chronic than acute invasive fungal sinusitis. Four patients (16 per cent) with acute invasive fungal sinusitis had no evidence of orbital involvement on scanning, despite clinical evidence of optic atrophy.

CONCLUSION

Orbital involvement is more common in invasive than non-invasive fungal sinusitis. The difference is more evident clinically than on computed tomography scanning. Patients with acute invasive fungal sinusitis may have limited evidence of orbital involvement on scanning, despite extensive clinical disease.

Melanized fungi in human disease

Melanized or dematiaceous fungi are associated with a wide variety of infectious syndromes, including chromoblastomycosis, mycetoma, and phaeohyphomycosis. [corrected]. Many are soil organisms and are generally distributed worldwide, though certain species appear to have restricted geographic ranges. Though they are uncommon causes of disease, melanized fungi have been increasingly recognized as important pathogens, with most reports occurring in the past 20 years. The spectrum of diseases with which they are associated has also broadened and includes allergic disease, superficial and deep local infections, pneumonia, brain abscess, and disseminated infection. For some infections in immunocompetent individuals, such as allergic fungal sinusitis and brain abscess, they are among the most common etiologic fungi. Melanin is a likely virulence factor for these fungi. Diagnosis relies on careful microscopic and pathological examination, as well as clinical assessment of the patient, as these fungi are often considered contaminants. Therapy varies depending upon the clinical syndrome. Local infection may be cured with excision alone, while systemic disease is often refractory to therapy. Triazoles such as voriconazole, posaconazole, and itraconazole have the most consistent in vitro activity. Further studies are needed to better understand the pathogenesis and optimal treatment of these uncommon infections.

Fungal rhinosinusitis: a clinicopathological study from South India

Fungal rhinosinusitis (FRS) is uncommon and accounts for 6-12% of culture or histologically proven chronic sinusitis. FRS may be acute or chronic. The aim of this paper was to study the histological features that contribute to the diagnosis and sub typing of FRS, using a retrospective review of all paranasal sinus mucosal biopsies from January 2005 to December 2008. The clinical features, predisposing conditions, imaging findings, and extent of the lesion were noted. The slides were reviewed with hematoxylin and eosin, Gomori's methenamine silver, and periodic acid Schiff stains. Culture reports were obtained wherever material was subjected to culture. There were 63 biopsies diagnosed as FRS (45.7%) out of 138 biopsies of chronic sinusitis in the study period. The FRS was classified as allergic in 15 (23.8%), chronic non-invasive (sinus mycetoma) in 1 (1.6%), chronic invasive in 10 (15.87%), granulomatous invasive in 19 (30%), and acute fulminant in 18 (28.5%) biopsies or surgical resections. Predisposing conditions were identified in 19 patients with diabetes mellitus as the commonest. Seventeen of the 18 patients with acute fulminant FRS had predisposing conditions. As per the results, the characteristic histological features were allergic mucin in allergic, fungal ball in chronic non-invasive, sparse inflammation and numerous hyphae in chronic invasive, non caseating granulomas with dense fibrosis in granulomatous invasive, and infarction with suppuration in acute fulminant FRS. Aspergillus sp. was the commonest etiologic agent. To conclude, predisposing risk factors were more common in invasive FRS than in non-invasive sinusitis and Aspergillus species was the most common etiologic agent.

Epidemiology and Medical Mycology of Fungal Rhinosinusitis

Fungal rhinosinusitis (FRS) refers to a spectrum of disease ranging from benign colonization of the nose and sinuses by pathogenic fungi to acute invasive and fatal inflammation extending to the orbit and brain. FRS is classified into two categories: invasive and noninvasive. Invasive FRS may again be subcategorized into acute invasive (fulminant) FRS, granulomatous invasive FRS, and chronic invasive FRS; while noninvasive FRS is subcategorized into localized fungal colonization, sinus fungal ball and eosinophil related FRS (including allergic fungal rhinosinusitis, eosinophilic fungal rhinosinusitis). This classification is not without controversies, and intermediate and semi-invasive forms may also exist in particular patients. Acute invasive FRS is an increasingly common disease worldwide among the immunocompromised patients and caused most frequently by Rhizopus oryzae, and Aspergillus spp. Granulomatous invasive FRS has mostly been reported from Sudan, India, and Pakistan and is characterized by noncaseating granuloma formation, vascular proliferation, vasculitis, perivascular fibrosis, sparse hyphae in tissue, and isolation of A. flavus from sinus contents. Chronic invasive FRS is an emerging entity occurring commonly in diabetics and patients on corticosteroid therapy, and is characterized by dense accumulation of hyphae, occasional presence of vascular invasion, sparse inflammatory reaction, involvement of local structures, and isolation of A. fumigatus. While localized fungal colonization describes the most benign of all fungal sinusitis in the superficial nasal crusts, sinus fungal ball is a dense mycetoma like aggregate of fungal hyphae in diseased sinuses. Common in southern Europe, especially France, majority of them are sterile on culture while 30-50% may yield Aspergillus spp. The definitions and pathogenesis of the group of syndromes in eosinophil related FRS (AFRS, EFRS) are contentious and a matter of intense research among otolaryngologists, pathologists, immunologists and microbiologists. While dematiaceous fungi are the foremost initiators of these syndromes in the west, Aspergillus flavus is the predominant pathogen in India and the Middle-East.

Paranasal fungal sinusitis: contributions of histopathology to diagnosis: a report of 60 cases and literature review

Sixty cases of fungal sinusitis are presented from 2 institutions, accumulated from 1971 to 2005. Fifty cases were from a large suburban general hospital and 10 from a major university referral center. Two of the 50 and 3 of the 10, respectively, were immunocompromised patients and had acute fulminant disease. This suggests that encountering the various forms of this disease may, in part, be dependent on the referral nature of the institution. The remainder were immune competent and had chronic symptoms of nasal discharge, stuffiness, and facial pain. Imaging studies frequently showed sinus expansion, opacification, and bone erosion, although no clinical or radiographic features were predictive of extrasinus extension. Chronic fungal sinusitis is principally represented by fungus ball/mycetoma and allergic fungal sinusitis. The recent literature suggests a predominance of or a predominant interest in allergic fungal sinusitis. Hyphal colonies and the presence of allergic mucin with scattered organisms are histologic observations and are the respective keys to these diagnoses. However, the etiologic role of the fungus in chronic cases is not settled. Patients with chronic sinusitis who yield positive sinus cultures only, but have no organisms visualized histologically, are not universally regarded as having fungal sinusitis. The interest in fungal sinusitis has generated a prominent role for the pathologist. An awareness of the various forms of the disease and thorough histopathologic study, including submission of all tissues removed at surgery and recognition of allergic mucin, are essential. Acute fulminant/invasive fungal sinusitis may require frozen section for adequate management.

Prevalence of allergic fungal sinusitis in refractory chronic rhinosinusitis in adult Malaysians

OBJECTIVE

To determine the prevalence of allergic fungal sinusitis (AFS) in refractory chronic rhinosinusitis (CRS) in adult Malaysians.

STUDY DESIGN AND SETTING

This cross-sectional study involved 30 immunocompetent CRS patients who underwent surgery. Specimens were sent for mycology and histopathologic analysis for identification of fungi. Clinical and immunological workup was performed for atopy in all patients and controls.

RESULTS

Fungal cultures were positive in 5 (16.7%) and 11 (36.7%) of 30 patients from nasal secretions and surgical specimens, respectively. Allergic mucin was found in 8 surgical specimens (26.7%). Hence, prevalence of AFS was 26.7%. The most common causative agent was Aspergillus sp. (54.5%). In 3 (37.5%) of 8 patients, AFS was found to be associated with asthma. Twenty-five percent (2/8 patients) had aspirin intolerance, and 62.5% (5/8 patients) had elevated total immunoglobulin E levels. All patients had positive skin test reactivity to fungal allergen.

CONCLUSIONS

This preliminary study suggests that AFS does exist in Malaysia. Proper handling of surgical specimens and accurate diagnosis by the pathologist and mycologist are essential.

Overview of fungal rhinosinusitis

The incidence of fungal rhinosinusitis has increased to such extent in recent years that fungal infection should be considered in all patients with chronic rhino sinusitis. In India though the disease was reported earlier only from northern regions of this country, nowadays the disease is increasingly diagnosed from other parts as well. The disease has been categorized with possible five types: acute necrothing (fulminant), chronic invasive, chronic granulomatous invasive, fungal hall (sinus mycetoma), allergic. The first three types are tissue-invasive and the last two are non-invasive fungal rhinosinusitis. However, the categorization is still controversial and open to discussion. Chronic fungal rhinosinusitis can occur in otherwise healthy host and Aspergillus flavus is the common etiological agent in Indian scenario. The pathophys iologic mechanism of the disease remains unclear. It may represent an allergic IgE response, a cell-mediated reaction, or a combination of two. Early diagnosis may prevent multiple surgical procedures and lead to effective treatment. Histopathology and radio-imaging techniques help to distinguish different types and delineate extension of disease process. Culture helps to identify the responsible etiological agent. The presence or absence oj precipitating antibody correlates well with disease progression or recovery. The most immediate need regarding management is to establish the respective roles of surgery and antifungal therapy. Non-invasive disease requires surgical debridement and sinus ventilation only, though, additional oral or local corticosterold therapy may be beneficial in allergie type. For invasive disease, the adjuvant medical therapy is recommended to prevent recurrence and further extension. Itraconazole has been found as an effective drug in such situation. Patients with acute neerotizing type require radical surgery and amphotericin B therapy.