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Fact Sheet: Fungal Sinusitis
Fungi are plant-like organisms that lack chlorophyll.
Since they do not have chlorophyll, fungi must absorb food from dead
organic matter. Fungi share with bacteria the important ability to
break down complex organic substances of almost every type (cellulose)
and are essential to the recycling of carbon and other elements in the
cycle of life. Fungi are supposed to "eat" only dead things, but
sometimes they start eating when the organism is still alive. This is
the cause of fungal infections; the treatment selected has to
eradicate the fungus to be effective.
In the past 30 years, there has been a significant increase in the
number of recorded fungal infections. This can be attributed to
increased public awareness, new immunosuppressive therapies
(medications such as cyclosporine that "fool" the body's immune system
to prevent organ rejection) and overuse of antibiotics
(anti-invectives).
When the body's immune system is suppressed, fungi find an opportunity
to invade the body and a number of side effects occur. Because these
organisms do not require light for food production, they can live in a
damp and dark environment. The sinuses, consisting of moist, dark
cavities, are a natural home to the invading fungi. When this occurs,
fungal sinusitis results.
TYPES OF FUNGAL SINUSITIS
Mycetoma fungal sinusitis produces clumps of spores,
a "fungal ball," within a sinus cavity, most frequently the maxillary
sinuses. The patient usually maintains an effective immune system, but
may have experienced trauma or injury to the affected sinuses).
Generally, the fungus does not cause a significant inflammatory
response, but sinus discomfort occurs. The noninvasive nature of this
disorder requires a treatment consisting of simple scraping of the
infected sinus. An anti-fungal therapy is generally not prescribed.
Allergic fungal sinusitis (AFS) is now believed to
be an allergic reaction to environmental fungi that is finely
dispersed into the air. This condition usually occurs in patients with
an immunocompetent host (possessing the ability to mount a normal
immune response). Patients diagnosed with AFS have a history of
allergic rhinitis, and the onset of AFS development is difficult to
determine. Thick fungal debris and mucin (a secretion containing
carbohydrate-rich glycoprotein's) are developed in the sinus cavities
and must be surgically removed so that the inciting allergen is no
longer present. Recurrence is not uncommon once the disease is
removed. Anti-inflammatory medical therapy and immunotherapy are
typically prescribed to prevent AFS recurrence. Note: A 1999 study published in the Mayo Clinic Proceedings asserts
that allergic fungal sinusitis is present in a significant majority of
patients diagnosed with chronic rhino sinusitis. The study found 96
percent of the study subjects with chronic rhino sinusitis to have a
fungus in cultures of their nasal secretions. In sensitive
individuals, the presence of fungus results in a disease process in
which the body's immune system sends eosinophils (white blood cells
distinguished by their lobulated nuclei and the presence of large
granules that attract the reddish-orange eosin stain) to attack fungi,
and the eosinophils irritate the membranes in the nose. As long as
fungi remain, so will the irritation.
Chronic indolent sinusitis is an invasive form of
fungal sinusitis in patients without an identifiable immune
deficiency. This form is generally found outside the US, most commonly
in the Sudan and northern India. The disease progresses from months to
years and presents symptoms that include chronic headache and
progressive facial swelling that can cause visual impairment.
Microscopically, chronic indolent sinusitis is characterized by a
glaucomatous inflammatory infiltrate (nodular shaped inflammatory
lesions). A decreased immune system can place patients at risk for
this invasive disease.
Fulminate sinusitis is usually seen in the
immunocompromised patient (an individual whose immunologic mechanism
is deficient either because of an immunodeficiency disorder or because
it has been rendered so by immunosuppressive agents). The disease
leads to progressive destruction of the sinuses and can invade the
bony cavities containing the eyeball and brain.
The recommended therapies for both chronic indolent and fulminate
sinusitis are aggressive surgical removal of the fungal material and
intravenous anti-fungal therapy. |
