Fungal Sinusitis

Updated: Oct 21, 2022
  • Author: Hassan H Ramadan, MD, MSc, FACS, FARS; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Practice Essentials

In the past, fungal infections of the sinuses have been blamed for causing most cases of chronic rhinosinusitis. [1]  This is because fungal elements are ubiquitous and can often be found in the nose and paranasal sinuses. However, in most situations, the presence of fungi in the sinuses is not related to sinusitis. The role of fungal antigens in the development of chronic rhinosinusitis has yet to be determined. [2, 3, 4]

Fungal sinus infections can be either noninvasive (benign) or invasive. Although invasive fungal sinusitis occurs in individuals who are immunocompromised, there have been several reports of invasive fungal infections in immunocompetent individuals. [5, 6, 7, 8]

Distinguishing invasive disease from noninvasive disease is important because the treatment and prognosis are different for each. Noninvasive disease has two varieties of presentations (fungal ball and allergic fungal rhinosinusitis), and invasive disease has three varieties of presentations (acute invasive, chronic invasive, and granulomatous invasive fungal sinusitis). This article reviews all five varieties.

Axial CT scan of sinuses shows a right fungal maxi Axial CT scan of sinuses shows a right fungal maxillary sinusitis with an expanding mass (possibly aspergillosis).

Workup in fungal sinusitis

Elevated serum fungus-specific immunoglobulin E (IgE) concentrations are often found in patients with allergic fungal rhinosinusitis. This is less common in patients with sinus mycetoma.

Computed tomography (CT) scanning of the paranasal sinuses in the coronal view is essential for the evaluation of patients in whom fungal sinusitis is suspected. [9, 10] Magnetic resonance imaging (MRI) with enhancement is often helpful in assessing patients with allergic fungal rhinosinusitis and in patients in whom invasive fungal rhinosinusitis is suspected. [10]

Management of fungal sinusitis

The treatment of choice for all types of fungal sinusitis is surgical, with patients commonly undergoing débridement to clear the burden of fungal elements. Medical treatment depends on the type of infection and the presence of invasion. In allergic fungal rhinosinusitis, for example, systemic steroids and allergy treatment may be indicated once surgery is performed and the diagnosis is confirmed. In invasive fungal sinusitis, medical treatment with systemic antifungal therapy is initiated once invasion is diagnosed.


History of the Procedure

Fungal infections of the paranasal sinuses are uncommon. The status of the patient’s immune system determines the type of fungal sinusitis that occurs. Invasive fungal sinusitis usually arises in individuals who are immunocompromised, although its occurrence has increased in the immunocompetent population.

The most common pathogens are Aspergillus and Mucor species. Aspergillus species can cause noninvasive or invasive infections, whereas Mucor species typically cause severe invasive infections. Invasive infections, which are characterized by dark, thick, greasy material found in the sinuses, can cause tissue invasion and destruction of adjacent structures (eg, orbit, central nervous system [CNS]). Noninvasive infections cause symptoms of sinusitis and often lead to nasal polyposis.

In noninvasive fungal sinusitis, the involved sinuses are opacified on radiographic studies, and routine cultures from the sinuses rarely demonstrate the fungus. However, the fungus is usually suspected upon reviewing the computed tomography (CT) scan result and is detected on removal of secretions from the sinus.



Fungal infections of the paranasal sinus can manifest as two distinct entities.

The more serious infection commonly occurs in patients with diabetes mellitus or in individuals who are immunocompromised. It is characterized by its invasiveness, tissue destruction, and rapid onset. Early detection and treatment are vital for these infections because of their associated high mortality rate.

A noninvasive infection is chronic and is usually treated for an extended period of time as chronic rhinosinusitis before the condition is recognized.



Noninvasive fungal sinusitis

Two forms are described in this category, allergic fungal rhinosinusitis (AFRS) and sinus fungal ball. Most commonly, Curvularia lunata, Aspergillus fumigatus, and Bipolaris and Drechslera species cause allergic fungal rhinosinusitis.

A fumigatus and dematiaceous fungi most commonly cause sinus fungal balls.

Allergic fungal rhinosinusitis occurs more commonly in African Americans and in individuals with low socioeconomic status. A study by Lu-Myers et al found that socioeconomic and demographic factors differed between patients with allergic fungal rhinosinusitis and those with chronic rhinosinusitis. Patients with chronic rhinosinusitis were more commonly White and older, with a higher income and greater access to primary care. The study, which involved a total of 186 patients (93 patients in each group), also found that patients with allergic fungal rhinosinusitis tended to have higher markers of disease severity, including greater quantitative serum IgE levels and higher Lund-Mackay CT-scan scores, than did patients with chronic rhinosinusitis. [11]

Invasive fungal sinusitis

Invasive fungal sinusitis includes the acute fulminant type, which has a high mortality rate if not recognized early and treated aggressively, and the chronic and granulomatous types.

Saprophytic fungi of the order Mucorales, including Rhizopus,Rhizomucor,Absidia,Mucor,Cunninghamella,Mortierella,Saksenaea, and Apophysomyces species, cause acute invasive fungal sinusitis.

A fumigatus is the fungus that is most commonly associated with chronic invasive fungal sinusitis.

Aspergillus flavus is the fungus most commonly associated with granulomatous invasive fungal sinusitis.



Allergic fungal rhinosinusitis

Allergic rhinitis is prevalent in people with, and is considered to be the trigger mechanism for, allergic fungal rhinosinusitis. Patients are immunocompetent and often have asthma, eosinophilia, and elevated serum fungus-specific IgE concentrations. [12]

Surgery reveals greenish black or brown material (ie, eosinophilic mucin), which has the consistency of peanut butter mixed with sand and glue. Eosinophilic mucin and polyps may form a partially calcified expansile mass that obstructs sinus drainage. Growth of the mass may cause pressure-induced erosion of sinus bone, rupture of sinus walls, and pressure to adjacent structures such as the orbit and brain, with occasional leakage of the sinus contents into the surroundings.

A study by Gupta et al indicated that allergic fungal rhinosinusitis tends to be more severe when granulomas are present. The study involved 57 patients with allergic fungal rhinosinusitis, including nine patients with granulomas, with the investigators finding that those with granulomas had a tendency toward orbital and skull base erosion, as well as telecanthus, diplopia, exophthalmos, and facial pain. [13]

Sinus fungal ball (mycetoma)

This condition is usually unilateral and most commonly involves the maxillary sinus, followed by the sphenoid sinus. Mucopurulent, cheesy, or claylike material is present at the time of surgery. Patients with sinus fungal ball are typically immunocompetent. Allergic conditions and fungus-specific IgE are less common.

Acute invasive fungal sinusitis

Acute invasive fungal sinusitis, also called fulminant invasive fungal sinusitis, results from a rapid spread of fungi through vascular invasion of sinus tissue, the orbit, and the CNS. It is common in patients with insulin-dependent diabetes mellitus and in persons who are immunocompromised. In rare cases, it has been reported in immunocompetent individuals. Typically, patients with acute invasive fungal sinusitis are severely ill with fever, cough, nasal discharge, headache, cranial neuropathies, and mental status changes. They usually require hospitalization.

Chronic invasive fungal sinusitis

Chronic invasive fungal sinusitis is a slowly progressive fungal infection with a low-grade invasive process. It occurs most commonly in patients with diabetes mellitus.

Non-specific rhinosinusitis symptoms that slowly progress are common. Orbital apex syndrome, which is characterized by a decrease in visual acuity and ocular immobility due involvement of the superior portion of the orbit, is usually associated with this condition and is an indicator of the disease's progression.

Granulomatous invasive fungal sinusitis

This condition has been reported almost exclusively in immunocompetent individuals from North Africa. Generally, proptosis is associated with granulomatous invasive fungal sinusitis.

Preinvasive fungal sinusitis

A study by Paknezhad et al indicated that in addition to the invasive and noninvasive forms of fungal sinusitis, an intermediate, or preinvasive, subtype exists. In this form, intramucosal fungal infiltration occurs, but neither direct angioinvasion nor wide extension beyond the submucosa is found. The investigators reported that patients with preinvasive fungal sinusitis appear to need only limited surgical débridement, rather than the extended and repeated débridement required in invasive fungal sinusitis. [14]



Allergic fungal sinusitis

Patients present with symptoms of chronic rhinosinusitis, which may include facial pressure, headache, nasal stuffiness, discharge, and cough. The condition should be suspected in individuals with intractable sinusitis and nasal polyposis.

Facial dysmorphia such as malar flattening, proptosis, or telecanthus is common, having resulted from the expansile effect of the disease on adjacent structures. Patients with allergic fungal sinusitis usually have atopy and have had multiple surgeries by the time of diagnosis. CT scanning of the sinuses reveals opacification with concretions and/or calcifications.

Sinus fungal ball (mycetoma)

The presentation of sinus fungal ball shares similarities with that of chronic rhinosinusitis. Cheek pressure and nasal congestion are common in patients with maxillary sinus fungal ball. Chronic headache is common in patients with sphenoid sinus fungal ball. Examination may reveal polyposis with evidence of sinusitis, mainly on one side. The main sign reported is a blowing of gravel-like material from the nose. Usually, sinus fungal ball is found accidentally on CT sinus scans.

Acute invasive fungal sinusitis

Patients are usually hospitalized and are very sick with fever, cough, nasal discharge, headache, and mental status changes. A high index of suspicion for early diagnosis is critical, especially in individuals who are immunocompromised. Acute invasive fungal sinusitis carries a mortality rate of up to 50%. [15]

Signs and symptoms include dark eschars on the septum, inferior and middle turbinates, and/or palate. In the late stages, signs and symptoms of cavernous sinus thrombosis and cranial neuropathies are present.

Chronic invasive fungal sinusitis

Patients present with symptoms of long-standing rhinosinusitis. Symptoms are usually not acute, and fever and mental status changes are absent.

Orbital apex syndrome, which is characterized by a decrease in visual acuity and by ocular immobility, due involvement of the superior portion of the orbit, is usually associated with this condition.

Nasal examination findings can be minimal. However, findings from the eye examination can be positive.

Granulomatous invasive fungal sinusitis

Patients present with symptoms of chronic rhinosinusitis associated with proptosis. Examination of the nasal cavity can be nonrevealing. However, findings from the eye examination are usually impressive.



The treatment of choice for all types of fungal sinusitis is surgical (see Surgical therapy).


Relevant Anatomy

See Surgical therapy.



All forms of fungal sinusitis require surgical treatment. The only contraindications to surgical management relate to the general condition of the patient. Before surgery is recommended, risks and benefits of the surgical procedure should be weighed against the risks of general anesthesia.