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Dan Carothers, MD
Chicago, IL
Is there a fungus among us? In short, yes.
Fungi as a group are found nearly everywhere on the planet, including the human body. Of the approximately 50,000 kinds of fungi, only a few dozen have been implicated in human illness. In most cases, these various fungi coexist in a natural balance with other microorganisms that colonize our bodies. However, in certain circumstances, fungi can cause infection ranging from minor to life-threatening in severity. Inflammation or infection of the sinuses by fungi is termed fungal sinusitis. Fungal sinusitis can be classified into 4 types:
- Fungal ball
- Allergic fungal sinusitis
- Chronic invasive sinusitis
- Acute invasive sinusitis.
A fungal ball is an overgrowth of fungal elements which typically occurs in the maxillary (or cheek) sinus. The organism involved is most often from the common bread mold family, Aspergillus. Patients with this condition may have a history of recurrent sinus infections, and the symptoms may be similar to bacterial sinusitis. A radiologic study (X-ray, CT, MRI) ordered to investigate this will show blockage of the involved sinus(es), without any damage to the surrounding bone (Figure #1). Treatment consists of removal of the fungal ball. In most cases, this is possible with a minimally invasive procedure termed endoscopic sinus surgery, with excellent cure rates.
Figure1
Fungal ball in the sphenoid sinus
The most common type of fungal infection is termed allergic fungal sinusitis. The fungi involved are mainly from the Dematiaceous family, including Bipolaris, Curvularia, and Alternaria, which are common in the environment. As in fungal ball, the symptoms can be similar to bacterial sinusitis. Nasal polyps and thick drainage are usually found on examination of the nose (Figure 2). Radiologic studies will show blockage of the affected sinuses and can show impressive bony thinning and occasionally bony destruction. Treatment consists of removal of the fungal elements, with re-establishment of sinus drainage. As in fungal ball, endoscopic sinus surgery is possible in most cases. Recurrence rates are higher than in fungal ball, due to the allergic component, inflammation, and nasal polyps associated with this condition. In many cases, lifelong medical and intermittent surgical management is necessary. Although the treatment of this condition is controversial, typical adjuncts to surgical removal may include systemic and/or topical steroids, antihistamines, antibiotics, anti-fungal medications, allergy immunotherapy and irrigations.
Figure2
AFS: Thick mucus in maxillary sinus
Acute and chronic invasive sinusitis are the most serious types of fungal sinusitis, and fortunately the least common. Acute invasive fungal sinusitis is a quickly advancing process that grows deeply into the sinus tissues and bones. Chronic invasive fungal sinusitis is a similar, but much slower infection. Patients who are affected with acute invasive sinusitis typically have a compromised immune system, such as after chemotherapy, or patients with uncontrolled diabetes. In contrast, most patients with chronic invasive sinusitis have a normal immune system. Common environmental Fungi from the families Rhizopus, Mucor, and Aspergillus are frequently found in this type of infection. Symptoms of this condition, like all types of fungal sinusitis, can be similar to bacterial sinusitis. On examination of the nose, mold spores and areas of dying tissue can be seen. The area involved in the infection can extent far beyond the confines of the nasal cavity and sinuses (Figure 3). Radiologic studies will show blockage of the involved sinuses, destruction of bone and swelling in the affected areas of the facial tissues. A combination of surgery and anti-fungal medications are required in this often-fatal infection.
Figure3
Invasive fungal sinusitis of the palate
Indeed, as in humans' interaction with other microorganisms, our interaction with fungi varies from benign coexistence to deadly infection. Fungal sinusitis has been felt to be uncommon, however, recently published data contradicts previous reports. A topic of much debate, the diagnosis and treatment of fungal sinusitis continues to frustrate physicians and their patients.
For more information regarding sinus infections, fungal or otherwise, contact your local Otorhinolaryngology specialist.
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