Sinus fungus is caused by the fungal organisms present in the air. The immune system normally prevents the fungus from growing in the sinuses of a healthy person, but in some instances, fungal infections cause inflammation in the nose and sinuses, according to the American Rhinologic Society. Doctors divide these infections into noninvasive and invasive fungal sinusitis.
The fungus ball is one type of noninvasive fungal infection. Normally due to the overgrowth of Aspergillus, a common mold, the fungus finds favorable conditions in the warm, moist atmosphere of the sinus. A fungus ball normally affects a single sinus, reports the American Rhinologic Society. It usually requires removal by surgery.
Chronic invasive fungal sinusitis typically lasts less than a month. It can affect any sinus but is most common in the ethmoid and sphenoid sinuses. Treatment involves surgery, use of antifungal medications and working to restore the patient’s immune system, advises the American Rhinologic Society.
Acute invasive fungal sinusitis can be life threatening, as it is the most serious form of sinus fungus. This form is rare and normally only seen in individuals with otherwise compromised immune systems. Patients undergoing chemotherapy for cancer or who receive bone marrow transplants have a greater chance of suffering from this type of infection, the American Rhinologic Society reports.