Sinusitis, or infection of the sinuses, has a wide variety of causes. Acute bacterial sinusitis, which most people are familiar with, is a short-term complication of the common cold and other viral illnesses. You develop sinus pain, fever and purulent (pus-containing) discharge from the nose. Treatment with antibiotics usually results in prompt recovery. When antibiotics do not cure the problem, surgery may be needed to drain the sinuses.

Invasive Fungal Sinus infection

There are also many types of sinus infection caused by fungi. The most serious is invasive fungal sinus infection, in which the fungi actually grow into the tissues lining the sinus cavities. This syndrome can be rapidly invasive or slower growing. The rapidly invasive forms occur in patients with severe immune-system problems. In these patients, the infection progresses rapidly, far more rapidly than the illness you describe -- in hours to days rather than weeks to months. The fungi can invade vital structures in the head, including the brain, and even cause death.

The other form of invasive fungal sinus infection progresses slowly over months. This infection can be difficult to diagnose, requiring a CT scan and sometimes-surgical biopsy. This type occurs in patients with diseases that affect the immune system less severely than the disorders associated with the rapidly invasive disease.

The treatment of invasive fungal sinusitis, whether rapid or slow growing, involves antifungal drugs and surgical removal of the infected tissue. The long-term prognosis depends on how quickly the disease is recognized and whether surgery successfully removes all of the infection.

Fungal Colonization

Another type of fungal sinus disease is fungal colonization, in which the fungi do not invade any tissues. In this illness, an obstruction in the sinus (such as a polyp) encourages the growth of fungi inside the cavity, forming what are known as "fungus balls." A fungus ball can further obstruct a sinus, leading to bacterial infection. In addition, a fungus ball can in rare cases cause enough pressure inside the sinus to affect important structures in the head. Treatment is surgical removal of the fungus ball and relief of whatever obstructed the sinus.

One issue regarding this condition bears special mention. Many people believe that they have had chronic sinus infections, when in actuality they never had a sinus infection. Instead, they have had allergic sinus disease, which can resemble infection. The only way to prove that someone has acute bacterial sinusitis is to puncture the sinus and draw out fluid to send for laboratory analysis.

Allergic Fungal Sinusitis

However, a form of allergic disease called "allergic fungal sinusitis" has symptoms almost the same as chronic bacterial disease. The discharge from the nose is thick. The patient usually has a history of allergies. Sending the discharge to the lab, where certain fungi are noted, can usually make diagnosis. The treatment of allergic fungal sinusitis involves surgery to remove obstructions such as polyps, plus anti-inflammatory corticosteroid medications. Once the symptoms are gone, using nasal steroids on an ongoing basis can often prevent the disease from recurring. In rare cases, the fungus has invaded tissues and antifungal drugs are needed as well.