A fungal sinus infection, also called fungal sinusitis, is when fungus causes an infection of the sinuses. The sinuses are air-filled cavities in the head that produce mucus (snot), which drains out of the nasal (nose) passages. It is important for the sinuses to drain properly to keep your nasal passages free of bacteria, germs, and allergens.
Symptoms of a fungal sinus infection include headache, stuffy nose, facial pain or pressure, and nasal drainage. Symptoms typically develop as a response to fungus that causes an allergic reaction or after exposure to fungus that infects the sinuses or nasal passages.
There are four different types of fungal sinus infections. Common symptoms across all types include:
People with a weakened immune system may develop more severe symptoms, such as facial numbness, changes to skin tone (skin may become lighter or darker), and swelling in the cheeks or eyelids.
Some symptoms are less common or indicate a specific type of fungal sinus infection. The main types of fungal sinus infections are allergic fungal sinusitis (AFS), saprophytic fungal sinusitis, fungus ball sinusitis, and invasive fungal sinusitis.
Some fungal sinus infections are acute (short-term), while others are chronic (long-lasting). Some types develop slowly over time while other types progress quickly.
Allergic Fungal Sinusitis
Allergic fungal sinusitis (AFS) is the most common type of fungal sinus infection. It is caused by an allergic reaction to different types of fungi, with the Aspergillus species being the most common culprit.
Symptoms typically include:
As AFS progresses, the sinuses become clogged with thick mucus, which causes them to increase in size and enlarge the appearance of the eyes and face. This type of fungal sinus infection typically requires surgery, followed by medical therapy to prevent recurrent infections.
Saprophytic Fungal Sinusitis
Saprophytic fungal sinusitis (SFS) initially presents without any symptoms. As the infection progresses, the infection bypasses the mucosa (the moist tissue lining the sinuses and nasal cavity) and enters the nerves, vessels, and bone. This can result in symptoms such as:
- Headache
- Facial pain
- Drainage (built-up mucus that drains down the back of the throat or out the nose)
- Bulging of the eyes
Fungus Ball Sinusitis
Fungus ball sinusitis often results from the inhalation of fungal spores or from a mucosal injury (damage or inflammation of the sinus’s inner lining).
The infection is asymptomatic (with no symptoms) at first. As the fungus grows, it forms clumps of bacteria-forming material that eventually form the shape of a ball. At this stage, symptoms may become more obvious and cause:
- Crusting inside the nose
- Facial pain
- Post-nasal discharge (mucus from the sinuses and nasal passages drips back into the throat)
This infection typically affects the maxillary sinus, the hollow space in the bones surrounding the nose. Surgery to open and rinse out the sinuses is often required to treat this infection.
Invasive Fungal Sinusitis
Invasive fungal sinusitis is a severe fungal infection that affects the linings of the sinuses and nasal passages. Over time, it can destroy nasal and sinus tissue.
Invasive fungal sinusitis has three different sub-types: acute invasive rhinosinusitis (AIRS), chronic invasive rhinosinusitis (CIRS), and granulomatous invasive sinusitis (GIFS).
Acute Invasive Rhinosinusitis (AIRS)
In AIRS, the fungus destroys the blood vessels lining the nose, causing tissue death. People with diabetes, people with an organ transplant, and people with lymphoma or leukemia are most at risk for AIRS.
Symptoms of AIRS may include a runny nose with clear mucus, nasal congestion, fever, and facial pain or pressure. Vision changes may occur in up to 50% of people, and some people with AIRS may have an orbital mass (abnormal growth of the eye socket).
In some advanced cases of AIRS, there may be few or no symptoms. As the infection can be life-threatening, treatment requires emergency surgery and antifungal medications.
Chronic Invasive Rhinosinusitis (CIRS)
CIRS affects the sinus tissues and typically progresses very slowly, taking months to years. CIRS commonly affects people with diabetes.
Symptoms of CIRS include bloody nasal discharge, a mass in the nasal cavity or paranasal sinuses (hollow, air-filled spaces in bones surrounding the nose), cacosmia (distorted sense of smell), and a blockage on one side of the nose. CIRS may also cause neurological symptoms or affect the maxillary sinus, causing changes in the skin.
Like AIRS, treatment requires anti-fungal medication. Sometimes, surgical debridement (removal of infected tissue) may be necessary.
Granulomatous Invasive Sinusitis (GIFS)
Research shows that many CIRS infections progress to GIFS, a rare fungal sinus infection that causes a severe immune response. This response damages and destroys the nose’s lining. GIFS does not commonly occur in the United States and other developed countries. It is more common in Northern Africa, Asia, and the Middle East.
Symptoms include the formation of non-caseating granulomas, which are inflammatory cell masses without a central area of dead tissue. Treatment may involve anti-fungal medications and surgical debridement (removal of infected tissue).
Seek medical care from a healthcare provider if you experience:
- Worsening symptoms
- Multiple sinus infections
- A fever lasting three to four days
- Symptoms that last more than 10 days without improvement
Visit your nearest emergency room (ER) if you experience more severe symptoms. Some symptoms that indicate a medical emergency include:
- Facial numbness
- Severe swelling
- Changes to the color of skin
A healthcare provider can diagnose a fungal sinus infection through a physical examination, imaging tests, lab work, or an endoscopic biopsy with histopathology.
An endoscopic biopsy with histopathology is a medical procedure in which a provider inserts an endoscope—a thin, flexible tube with a light and camera—through the nostrils to take a small tissue sample. They will then examine the sample under a microscope to determine whether an infection is present.
A fungal sinus infection is caused by fungus that enters your sinuses and nasal passages. There are four main types of fungal sinus infections: saprophytic fungal sinusitis, fungus ball sinusitis, allergic fungal sinusitis, and invasive fungal sinusitis.
Common symptoms of fungal sinus infections include headache, nasal congestion, and facial pain or pressure. However, symptoms can vary depending on the type of fungal sinus infection.
Treating a fungal sinus infection is necessary to prevent further health complications and, in some cases, to prevent the progression of symptoms that can become life-threatening. If you think you may have symptoms of a fungal sinus infection, see your healthcare provider for diagnosis and treatment.
