Approximately 5-10% of patients affected by chronic rhinosinusitis actually carry a diagnosis of allergic fungal sinusitis (AFS). Atopy is characteristic of the disease; approximately two thirds of patients report a history of allergic rhinitis, and 90% of patients demonstrate elevated specific IgE to one or more fungal antigens. Approximately 50% of patients in a series by Manning et al had asthma. No linkage to aspirin sensitivity has been established.
Incidence of allergic fungal sinusitis (AFS) appears to be impacted by geographic factors. Review of world literature reveals that most sites reporting cases of allergic fungal sinusitis (AFS) are located in temperate regions of relatively high humidity. However, incidence of allergic fungal sinusitis (AFS) varied remarkably based on the location of reporting sites. Allergic fungal sinusitis (AFS) in the United States was encountered most commonly within the Mississippi basin, the Southeast, and the Southwest. The reason for this geographic difference remains unexplained.
Allergic fungal sinusitis (AFS) is most common among adolescents and young adults; the mean age at diagnosis is 21.9 years. The male-to-female (M/F) ratio of allergic fungal sinusitis (AFS) differs slightly between published reports but is believed to be equal when all ages are evaluated together. A literature review of 98 cases in the 1980s and early 1990s from 29 published journal articles reported an equal M/F incidence. A review by the author and colleagues of 151 patients at the University of Texas (UT) at Southwestern also revealed an equal M/F ratio, with ages ranging from 5-75 years. [10]
However, the M/F ratio may be age dependent and different in children and adults. In the review of patients at UT Southwestern, in children, males dominated (M/F ratio 2.1:1; average age, 13 y), and in adults, females dominated (M/F ratio 1:1.4; average age, 36 y). When evaluating the average ages and sex ratios of other studies, series with younger average ages are more likely to have a male predominance. The average ages in the male-dominated series were 25 and 27 years, while the average age in the female-dominated series was 33 years. The only other pediatric series consisted of 10 patients and had an M/F ratio of 1.5:1, with a mean age of 13.6 years. Interestingly, when 2 series of patients from a single institution were reviewed over time, an early study had an M/F ratio of 1.5:1, with an age range of 13-51 years (average age, 27.5 y), and a later review had an M/F ratio of 1:1.4, with an age range of 13-69 years (no average age given).
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Left middle meatus with suctioning of thick allergic mucin from the ethmoid bulla in the center of the picture; the end of the suction is in the inferior portion of the picture.
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The viscosity of a thick allergic mucin being suctioned from the nasal cavity and vestibule in a patient with allergic fungal sinusitis.
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View just inside the nasal vestibule showing diffused polyposis extending into the anterior nasal cavity and vestibule; the septum is on the right, and the right lateral vestibular wall (nasal ala) is on the left. The polyps all are in the center. The polyps almost hang out of the nasal vestibule.
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A 15-year-old boy with allergic fungal sinusitis causing right proptosis, telecanthus, and malar flattening; the position of his eyes is asymmetrical, and his nasal ala on the right is pushed inferiorly compared to the left.
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A 9-year-old girl with allergic fungal sinusitis displaying telecanthus and asymmetrical positioning of her eyes and globes.
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Coronal CT scan showing extensive allergic fungal sinusitis involving the right side with mucocele above the right orbit and expansion of the sinuses on the right.
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Typical view of a middle meatus in a patient with allergic fungal sinusitis with expansion of the ethmoid complex and extension of the middle turbinate more inferiorly. This is a postoperative view.
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Coronal CT scan showing typical unilateral appearance of allergic fungal sinusitis with hyperintense areas and inhomogeneity of the sinus opacification; the hyperintense areas appear whitish in the center of the allergic mucin.
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Coronal MRI showing expansion of the sinuses with allergic mucin and polypoid disease; the hypointense black areas in the nasal cavities are the actual fungal elements and debris. The density above the right eye is the mucocele. The fungal elements and allergic mucin in allergic fungal sinusitis always look hypointense on MRI scanning and can be mistaken for absence of disease.
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Immediate postoperative 30° angled view showing the complete removal of polyps with a widened frontal sinus recess superiorly and widened ethmoid cavity in the mid portion. The middle turbinate is on the right, pushed against the septum. The lateral nasal wall is on the left.
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Fungal ball in the right maxillary sinus.
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Fungal debris being removed from the ethmoid complex. A suction device is seen in the right lower corner of the picture.
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Allergic mucin, fungal debris, and polyps are shown after removal from the patient. The scale is in inches.
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Coronal CT scan showing the postoperative view following removal of disease after significant disease recurred on both the right and left sides of the nasal cavity and sinuses; mild mucosal thickening of all involved sinuses is present, with some moderate thickening of the left maxillary sinus. All disease, even the lateral mucocele, was removed or drained endoscopically.
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Two-week postoperative endoscopic picture showing polypoid thickening already in the ethmoid cavities while the patient was still on tapering steroids; on the left is the lateral nasal wall. The right shows the middle turbinate next to the septum.
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A polypoid recurrence in the center of the ethmoid cavity. The septum is on the left.