An article published in the Mayo Clinic Proceedings in September, 1999 by Dr. Gene Kern's group at the Mayo Clinic suggests that fungal sinusitis may be much more common than previously thought. Fungal growth was found in 96% of patients with chronic sinusitis. The difference between those with chronic sinusitis and the normal population was that their eosinophiles ( a type of white blood cell involved in allergic and other reactions) had become activated. The eosinophiles had released a product called Major Basic Protein which attacks the fungus but is very irritating to the lining of the sinuses. It is then speculated that this injury allows the bacteria to proliferate. The concern is whether our treatment of sinusitis should be directed at treatment of the fungus rather than the bacteria. This topic is extremely controversial, but most specialists in sinusitis now agree that it is an important factor in some patients with sinusitis. For more information please go to the separate page on fungal sinusitis, the address of which is below.
Antifungal agents such as Sporanox or Amphotericin B can be used either as oral agents or topically. Both are difficult to use for a variety of reasons, but work is being done on these and other agents. That is an area that requires an extensive amount of work.
Surgery, irrigation, steroids and immunotherapy are helpful, but it can be extremely difficult to treat.
Fungal sinusitis is broken down into several categories: Allergic, Fungus balls (Mycetoma), and Invasive.
Allergic fungal sinusitis (AFS) is commonly caused by Aspergillus(which is frequently found in air conditioners), as well as Fusarium, Curvularia, and others. Patients often have associated asthma. The criteria include CT or MRI confirmation, a dark green or black material the consistency of peanut butter called "allergic mucin" which typically contain a few hyphae, no invasion, and no predisposing systemic disease. Charcot-Leyden crystals, which are breakdown products of eosinophiles are often found. Usually patients are found to be allergic to the fungus, although this is controversial. This disease is analogous to Allergic Bronchopulmonary Aspergillosis. This problem is most similar to the type described at the Mayo clinic, but these patients have a much different character to their mucus.
Fungus balls often involve the maxillary sinus and may present similarly to other causes of sinusitis including a foul smelling breath. In addition to radiological abnormalities, thick pus or a clay-like substance is found in the sinuses. There is no allergic mucin, but dense hyphae are found. There is no invasion. There is an inflammatory response in the mucosa. Upon looking into the sinus, the fungus ball can vary in size from 1 mm or smaller to a size which completely occupies the sinus. It may have a greenish-black appearance. Removal of the fungus ball is the typical treatment.
Invasive sinusitis can progress rapidly, and typically necessitates surgery, often on a emergent basis and often requiring Amphotericin B intravenously as well. There have been some forms of invasive sinusitis which can cause proptosis. There is a form of chronic invasive fungal sinusitis which is associated with visual abnormalities due to bony erosion from the ethmoids.
Where in our home are we most likely to introduce these fungi into our breathing air at home?
Our air conditioning! Too often, we neglect proper cleaning of this device which is responsible for conditioning the very air we breathe at home. Even if we do clean it, how do we know if a proper job is done with the right chemicals and procedures to do a proper job of it?