Invasive Fungal Sinusitis (Fungal Sinus Infection)

What Is Invasive Fungal Sinusitis?

Invasive fungal sinusitis is an infection of the nasal and sinus lining that leads to inflammation and loss of tissue as it spreads into nearby areas like blood vessels or bones.

Fungi are often present in our paranasal sinuses, where they sometimes cause inflammation or infection. Most fungal infections of the sinuses are noninvasive, meaning they won't spread to surrounding tissues.

However, symptoms of both noninvasive and invasive fungal infections start out like a typical sinus infection, with:

• Congestion (stuffed up nose).
• Discharge (runny nose).
• Facial pain and swelling.

While these symptoms are similar to those of a regular sinus infection, they may also indicate a more severe condition, such as invasive fungal sinusitis. That’s why you need to see a health care provider to get a proper diagnosis.

Is invasive fungal sinusitis contagious?

Experts believe that fungal sinus infections are not contagious. Only sinus infections caused by viruses can spread from person to person.

Doctors agree that most people who get fungal sinusitis infections have compromised immune systems and exposure to large amounts of fungus.

What are the types of invasive fungal sinusitis? 

There are two types of invasive fungal sinus infections — acute and chronic.

The acute version is more serious. As the fungus reproduces, it spreads rapidly into the blood vessels, eye area, and central nervous system — with devastating results to the tissues.

Those with chronic invasive fungal sinusitis usually have symptoms of a long-standing sinus infection, including:

• Congestion.
• Drainage.
• Pressure in the forehead, nose, and behind the eyes.

Orbital apex syndrome is also a sign of chronic fungal sinus infection. Its symptoms include decreased vision and eye mobility due to the spread of fungi into the eye and orbit.

How common is invasive fungal sinusitis?

There are no precise statistics for invasive fungal rhinosinusitis. It is considered a rare but serious condition with a high risk of death or complications. Even after treatment, as many as 20% to 80% of patients may experience severe outcomes, including death or lasting health issues.

What causes invasive fungal sinusitis?

Fungi that cause illness in people mostly fall into two groups: molds and yeasts. Fungal sinus infections are usually caused by molds, not yeasts. Molds are made up of many cells and have thread-like structures called hyphae, while yeasts are single-celled.

Fungi are everywhere in the air around us, but most of the time, they don’t harm the nose or sinuses. Just having fungi in the sinuses doesn’t mean someone has an infection.

Whether or not fungi cause diseases often depends on the strength of a person’s immune system.

People are more likely to get a fungal sinus infection if they:

• Are undergoing chemotherapy.
• Have a weakened immune system or are on immunotherapy.
• Have diabetes, HIV/AIDS, or another underlying chronic health condition.
• Take corticosteroid medications.

Common fungi-related infections include:

• Blastomycosis — Caused by the fungus Blastomyces, which is most prevalent in the eastern United States, but also found in the midwestern, south-central, and southeastern states. This fungus thrives in moist soil and decomposing plant matter, such as wood chips and leaves.
• Coccidioidomycosis (valley fever) — Caused by the fungus Coccidioides, which lives in the soil and is found in the southwestern U.S. and some parts of the Pacific Northwest.
• Histoplasmosis — Caused by the fungus Histoplasma, which predominantly lives in soil in the central and eastern United States. However, it can also thrive in other parts of the country, especially if the environmental conditions, such as soil pH, are suitable. It grows particularly well in areas with large amounts of bird or bat droppings.

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What Are the Signs and Symptoms of Invasive Fungal Sinusitis?

Acute invasive fungal sinusitis symptoms

People with acute invasive fungal sinusitis often are very ill and may have some of the following symptoms:

• Cough.
• Dark ulcers in the nasal canal or on the roof of the mouth.
• Facial pain, numbness, or swelling.
• Fever.
• Headache.
• Mental status changes.
• Nasal discharge.
• Visual disturbances.

Chronic invasive fungal sinusitis symptoms

Those with chronic invasive fungal sinusitis usually have symptoms of a long-standing sinus infection, including:

• Pressure in the forehead, nose, and behind the eyes.
• Congestion.
• Drainage.

Orbital apex syndrome is also a sign of chronic sinus infection. Its symptoms include decreased vision and eye mobility due to the spread of fungi into the eye and orbit.

When should I see a doctor about my invasive fungal sinusitis symptoms?

Seek medical care immediately if you suspect invasive fungal sinusitis, as it can spread rapidly to the eyes, brain, and blood vessels, causing blindness, stroke, or death. Early diagnosis and aggressive treatment (often both medical and surgical) dramatically improve survival

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How Do You Diagnose Invasive Fungal Sinusitis?

Many people with invasive fungal infection are misdiagnosed as having community-acquired pneumonia or are diagnosed late, leading to potentially life-threatening treatment delays. That’s because the condition can appear with a wide range of symptoms.

To diagnose and treat this serious disease quickly, doctors need to gather a full medical history, check for any existing health problems  — especially if you have a weakened immune system — and do a physical exam. Understanding these factors will help them figure out what’s going on and act quickly.

If you live in an area where these fungi are endemic, or you are potentially exposed to fungi through your occupation, mention this to your provider so they can test for fungal infection.

Tests to diagnose invasive fungal infection

Imaging tests are important for diagnosing acute invasive fungal sinusitis, but they can't confirm it alone.

• CT scans help see differences in sinus structures and how the infection spreads. Early signs include thickened nasal and sinus linings. More specific signs, like bone erosion and brain involvement, appear later and can lead to worse outcomes. The infection can spread beyond the sinuses even if the bone walls are intact.
• MRI scans are better for distinguishing mucus from swelling and checking how far the infection has spread. A special MRI with gadolinium can show areas of tissue damage, which can indicate how aggressive the infection is. This damage can make the infection resistant to antifungal drugs and may require surgery.
• Nasal endoscopy can show changes in the nasal lining, like swelling, discoloration, and tissue death. During the endoscopy, your doctor will take tissue samples from those areas for biopsy, a test in which the tissue is examined under a microscope by a pathologist.
• Biopsy results are crucial for diagnosis. Special stains and tests can identify the fungi, which can help your doctor recommend the right treatment. However, these tests take time, so treatment should start before results are in. Sometimes, samples for biopsy need to be taken surgically, especially from hard-to-reach areas like the sphenoid sinus.

When examined under a microscope, biopsy results might reveal the following diagnoses:

• Allergic fungal sinusitis (AFS) — Shows presence of Charcot-Leyden crystals — similar to what’s seen in asthma patients. People with AFS usually have nasal polyps, eosinophilic mucin (thick mucus filled with immune cells), and high levels of IgE, a marker of allergic response. The mucus may also show patterns shaped like tide lines or tree rings.
• Fungus ball — A clump of fungus mixed with dead tissue, it can resemble AFS under a basic microscope, but a stronger microscope helps tell them apart.
• Granulomatous invasive fungal sinusitis (GIFS) — Usually showing up in people with normal immune systems, GIFS features a type of inflammation called granulomas beneath the sinus lining. Some long-term fungal sinus infections can turn into GIFS, so regular biopsies are needed to monitor changes.
• Invasive fungal sinusitis (IFS) — The type that mostly affects people with weakened immune systems. Under the microscope, doctors may see dead tissue and blocked blood vessels caused by the fungus invading the sinus walls.

Invasive fungal sinusitis prognosis

Prognosis is usually good for AFS, but can be dire for IFS, especially if the person’s immune system cannot be restored.

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How Do You Treat Invasive Fungal Sinusitis?

Acute invasive fungal sinusitis is a medical emergency. Once you receive a diagnosis, you'll need surgery right away to remove all dead and infected nasal and sinus tissue.

The chronic type also requires surgery and long-term medical therapy. The appropriate treatments should be given within 14 days from the time the symptoms begin to prevent serious complications.

Minimally invasive surgery for invasive fungal sinusitis

At UPMC, the preferred surgical treatment for invasive fungal sinusitis is the Endoscopic Endonasal Approach (EEA). This innovative, minimally invasive technique uses the nose and nasal cavities as natural corridors to access hard-to-reach or previously inoperable conditions.

Through the Endoscopic Endonasal Approach (EEA), surgeons can directly access the infected tissue through the natural corridor of the nose.

This state-of-the-art treatment allows surgeons to remove the infected tissue through the nose and nasal cavities, without making an open incision.

Benefits of EEA include:

• No incisions to heal.
• No disfigurement.
• Faster recovery time.

Follow-up treatment for invasive fungal sinusitis

Treatment also includes follow-up with antifungal drugs.

People with invasive fungal sinusitis need to remain under long-term observation by a doctor, as recurrence is common.

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