Fungal sinusitis involves inflammation of the sinuses due to the presence of fungi. The sinuses are hollow, air-filled spaces near the nose, cheeks, and eyes.

There are two different classes of fungal sinusitis: noninvasive and invasive.

This article looks at fungal sinusitis, including the types, symptoms, causes, diagnoses, and treatments.

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Doctors categorize fungal sinusitis as either noninvasive or invasive. Subtype classification depends on the extent of fungal involvement in the sinuses.

Noninvasive subtypes

The three subtypes of noninvasive fungal sinusitis include:

  • Allergic fungal sinusitis: This is the most common form of fungal sinusitis. This form of sinusitis usually occurs due to an allergic reaction to common fungi.
  • Fungal ball sinus infection: This type of sinusitis occurs when fungus becomes caught in the sinuses and forms clumps containing bacteria.
  • Saprophytic fungal sinusitis: In this form of sinusitis, mold grows on top of the mucus inside the nose. It does not infect the nasal tissue.

Noninvasive fungal sinusitis tends to occur in immunocompetent people.

Invasive subtypes

There are three subtypes of invasive fungal sinusitis:

  • Acute invasive rhinosinusitis: This type, although rare, has an aggressive course and will cause people to be very ill, so immediate medical treatment is necessary.
  • Granulomatous invasive sinusitis: This type of fungal sinusitis is uncommon. For unknown reasons, people with typical immune system function develop a severe reaction to the presence of the fungus.
  • Chronic invasive rhinosinusitis: This occurs in people with compromised immune systems. Fungus gets into the tissues and gradually damages the nasal or sinus tissues.

Invasive fungal sinusitis is more likely to develop in people with compromised immune systems.

The symptoms of fungal sinusitis are similar to those of sinusitis, which occurs due to a viral or bacterial infection.

Common symptoms of fungal sinusitis may include:

In some cases, symptoms of invasive fungal sinusitis tend to progress and become more serious. Less common symptoms that may occur include:

Fungal sinusitis can occur when a type of fungus enters the nasal cavity and becomes trapped in the sinuses.
Microscopic fungi exist throughout the environment.

When someone has exposure to certain types of fungi, it does not always lead to sinusitis symptoms or illness. Although many types of fungi are harmless and do not cause illness, some can make a person sick.

Types of fungus

The most frequent cause of allergic fungal sinusitis and invasive fungal sinusitis is Aspergillus. Candida is also another likely cause.

Other concerning causes of invasive fungal sinusitis include Rhizopus and Mucor fungi.

Other factors

An individual’s immune system function often affects whether they become symptomatic. For example, people with diabetes or those that take corticosteroids have an increased risk of fungal sinusitis. Additionally, someone immunocompromised due to chemotherapy has a higher risk of developing fungal sinusitis.

Doctors diagnose fungal sinusitis through a combination of personal medical history, physical exam, imaging tests, and fungal culture.

A healthcare professional examines the neck and uses an endoscope to view the nasal cavity.

The doctor may also take a sample of mucus inside the nose to determine the presence of fungus. Doctors also recommend CT or MRI scans to check for fungal growth or tissue damage, especially if they are considering surgery.

Treatment for fungal sinusitis may depend on the extent of the infection and a person’s immune system function. Someone who is immunocompromised needs treatment quickly.

Doctors must distinguish between invasive fungal sinusitis — which requires emergency treatment — and allergic fungal sinusitis — which has a benign course and doctors can manage selectively.


Usually, treatment for invasive fungal sinusitis may include antifungal medication. Amphotericin is one of the main antifungal medications, as it works well on Aspergillus.

Doctors may administer antifungal medication either before surgery or after. In some cases, antifungal medication alone may work well enough to treat invasive fungal sinusitis.

According to this 2019 research, administering antifungal medication early leads to improved survival rates in people with fungal sinusitis.

Older research demonstrates that allergen immunotherapy to fungi is a promising treatment for decreasing the recurrence of allergic fungal sinusitis.


For invasive fungal sinusitis, surgeons may use different types of procedures depending on the extent of damage to the tissues. Surgery aims to clear the fungus and remove any dead tissue.

Acute invasive fungal sinusitis is one of the rare sinus emergencies. Doctors consider surgical debridement a necessary intervention.

In many cases, surgery is successful at preserving healthy tissue and removing fungus. For example, this 2022 meta-analysis found that endoscopic sinus surgery had a 98.1% success rate when treating fungal ball sinusitis.

Surgery is one of the main ways to manage invasive fungal sinusitis. While it is also relevant to the noninvasive type, it is more important in the former.

Fungal sinusitis involves swelling of the sinuses due to the presence of some type of fungus. Additional symptoms can include facial pressure and congestion. People with a compromised immune system are more likely to develop invasive fungal sinusitis. Many immunocompetent people also get fungal sinusitis, but it is the noninvasive type.

Prompt treatment helps decrease complications. Treatment may include antifungal medication and surgery when needed.