Fungal Sinus Infections


Sinusitis, or infection of the sinuses, is a common problem affecting millions of people in the United States every year. Most of these cases of sinusitis are mild and caused by viral and bacterial infections. Less commonly, sinus infections can be caused by fungus.

Fungi are found throughout nature, and airborne fungus can be inhaled into the nose and lungs, causing various types of infections in the respiratory tract.

Fungal infections of the sinuses can be divided into two major types: non-invasive and invasive.

Non-invasive fungal sinusitis affects people with normal immune systems and does not spread beyond the sinuses. Examples of non-invasive fungal sinusitis include fungal colonization, allergic fungal sinusitis, and fungus ball.

Invasive fungal sinus infections usually only affect people with diminished immune systems (such as in people with cancer and uncontrolled diabetes mellitus) and have the ability to spread to other surrounding tissue and can become life-threatening. Examples of invasive fungal sinus infections include acute, chronic and granulomatous forms.

Fungus Colonization

Structural abnormalities and chronic sinus conditions can predispose a person to be colonized by fungus. This means that fungus may be found on a culture taken from the nose or sinuses, but there are no signs or symptoms of a sinus infection.

Treatment is not needed for fungal colonization of the sinuses.

Allergic Fungal Sinusitis

Allergic fungal sinusitis (AFS) is basically a severe allergic reaction as a result of a fungus within the sinuses. AFS is characterized by a chronic non-invasive sinus infection (at least 12 weeks in duration) with nasal polyps, the presence of fungi and eosinophils in sinus contents (obtained from sinus surgery) when placed under a microscope, characteristic findings on a sinus CT, and positive allergy tests to fungi.

People with AFS often have severe nasal congestion, trouble smelling, and often report brown, black, or "peanut butter" nasal discharge. Sinus pressure, headaches, double vision, and proptosis may also occur. Types of fungi that are common causes of AFS include Aspergillus, Alternaria, Cladosporium, Bipolaris and Curvularia.

Treatment of AFS typically involves sinus surgery, although recurrence is common unless medical treatments are also used. Medical treatments for AFS include oral corticosteroids starting immediately after surgery and lasting for weeks to months, saline irrigation, nasal corticosteroid sprays, as well as allergen immunotherapy (allergy shots). Topical and systemic antifungal medications are not usually recommended and have not been found to be helpful in various studies treating people with AFS.

Fungus Ball

A fungus ball is a well-formed mass of fungus found in one or more of the sinus cavities. Fungus balls are usually caused by Aspergillus, and often cause symptoms of nasal congestion, headache, and sinus pressure -– although some people with a fungus ball may not have any symptoms. Treatment consists of surgical removal of the fungus ball, which essentially cures the problem.

Antifungal medications are not necessary.

Invasive Fungal Sinusitis

Invasive fungal infections extend beyond the sinuses and can infect the surrounding bone, soft tissue, eyes and brain. Acute and chronic forms of invasive fungal sinusitis usually affect people with suppressed immune systems, such as that caused by cancer, chemotherapy drugs, or uncontrolled diabetes mellitus. Symptoms often include facial pain, eye swelling, blindness, fever, and nose bleeds. Treatment involves surgical removal of the fungal infection and antifungal medications. Prognosis of these conditions is poor if the underlying immune system problem is not corrected.

Granulomatous invasive fungal sinusitis affects people living in the Sudan, India, and Pakistan who appear to have normal immune systems. Symptoms are similar to those people with AFS, but this condition is not a result of a fungal allergy. Treatment includes surgical removal of the fungal infection and antifungal medications.

Learn more about the diagnosis and treatment of sinusitis.


Thompson GR, Patterson TF. Fungal Disease of the Nose and Paranasal Sinuses. J Allergy Clin Immunol. 2012;129:321-6.