Fungal Sinusitis 

Fungal infections of the sinuses have recently been blamed for causing most cases of chronic rhinosinusitis. The evidence, though, is still controversial. Most fungal sinus infections are benign or noninvasive, except when they occur in individuals who are immunocompromised. Several reports are available that have shown invasive fungal infections in immunocompetent individuals.^{[1, 2, 3]}

Distinguishing invasive disease from noninvasive disease is important because the treatment and prognosis are different for each. Noninvasive disease has 2 varieties of presentations, and invasive disease has 3 varieties of presentations. This article reviews all 5 varieties. For excellent patient education resources, see eMedicine's Headache Center. Also, visit eMedicine's patient education article, Sinus Infection.

Fungal infections of the paranasal sinuses are uncommon and usually occur in individuals who are immunocompromised. However, recently, the occurrence of fungal sinusitis has increased in the immunocompetent population.

The most common pathogens are from Aspergillus and Mucor species. Aspergillosis can cause noninvasive or invasive infections. Invasive infections are characterized by dark, thick, greasy material found in the sinuses. Invasive infections can cause tissue invasion and destruction of adjacent structures (eg, orbit, CNS). Noninvasive infections cause symptoms of sinusitis, and the sinus involved is opacified on radiographic studies. Routine cultures from the sinuses rarely demonstrate the fungus. However, the fungus is usually suspected upon reviewing the CT scan result and is detected on removal of the secretions from the sinus.

Fungal infections of the paranasal sinus can manifest as 2 distinct entities.

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

Noninvasive infections are chronic and are usually treated for extended periods as chronic sinusitis before the condition is recognized.

Noninvasive fungal sinusitis

Two forms are described in this category: allergic fungal sinusitis and sinus mycetoma/ball.

Most commonly, Curvularia lunata,Aspergillus fumigatus, and Bipolaris and Drechslera species cause allergic fungal sinusitis.

A fumigatus and dematiaceous fungi most commonly cause sinus mycetoma.

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 only fungus associated with chronic invasive fungal sinusitis.

Aspergillus flavus exclusively has been associated with granulomatous invasive fungal sinusitis.

Allergic fungal sinusitis

Allergic rhinitis is prevalent in this group and is considered to be the trigger mechanism behind allergic fungal sinusitis. Patients are immunocompetent and often have asthma, eosinophilia, and elevated total fungus-specific immunoglobulin E (IgE) concentrations.^[4]

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

Sinus mycetoma

This condition is usually unilateral and involves the maxillary sinus. Mucopurulent, cheesy, or claylike material is present at the time of surgery. Patients with sinusitis mycetoma are immunocompetent. Allergic conditions and fungus-specific IgE are less common.

Acute invasive fungal sinusitis

Acute invasive fungal sinusitis results from a rapid spread of fungi through vascular invasion into the orbit and CNS. It is common in patients with diabetes and in patients who are immunocompromised and has been reported in immunocompetent individuals. Typically, patients with acute invasive sinusitis are severely ill with fever, cough, nasal discharge, headache, 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 and usually occurs in patients with diabetes.

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

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.

Allergic fungal sinusitis

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

Some patients may present with proptosis or eye muscle entrapment. These patients 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 mycetoma

Presentation of patients with sinus mycetoma is similar to that of patients with sinusitis. Examination may reveal polyposis with evidence of sinusitis, mainly on one side. The main report is blowing of gravel-like material from the nose. Usually, sinus mycetoma is found accidentally on CT scanning of the sinuses.

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.

Signs and symptoms include dark ulcers on the septum, turbinates, or palate. In the late stages, signs and symptoms of cavernous sinus thrombosis are present.

Chronic invasive fungal sinusitis

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

Orbital apex syndrome, which is characterized by a decrease in vision and ocular immobility due to a mass in 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 sinusitis 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).

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.