Samer Fakhri, MD, FACS, FRCS(C)
Professor & Chair
Department of Otolaryngology-Head & Neck Surgery
American University of Beirut Medical Center
Department of Otorhinolaryngology- Head & Neck Surgery
University of Texas Medical School at Houston
Patients with uncontrolled levels of blood sugar are considered effectively immunosuppressed due to the harmful effects of hyperglycemia on different parts of the immune system that fight infections. Skin and urine infections are the most common among diabetics and in general are either self-limiting or respond favorably to treatment with antibiotics. Some infections, however, are more serious and may be life-threatening. In the ENT (ear, nose, and throat) area, such infections include Invasive Fungal Sinusitis and Necrotizing Otitis Externa. Fortunately these infections are not very common and are typically encountered in advanced cases of uncontrolled hyperglycemia and diabetic ketoacidosis. Prompt diagnosis and initiation of treatment are critical to maximize the outcome in these patients.
Invasive Fungal Sinusitis
This is an infection that arises from fungi and mold normally present ubiquitously in nature and humans including the nasal cavity. The spores of these fungi are inhaled through the nose. In healthy individuals, tiny little hair cells, called cilia, present on the inner lining of the nose transport these spores to the pharynx and they are cleared through the gastrointestinal tract. Under certain conditions such as high glucose levels some of the mold like Rhizopusmultiply.This is because they have an enzyme, ketone reductase that allows them to thrive in high glucose, acidic conditions.
Aspergillus or members of the class Zygomycetes (Mucor, Rhizopus) are the most frequent causative agents. The disease has an aggressive course, with fungus rapidly growing through sinus tissue and bone to extend into the surrounding areas of the brain and eye. This is the most dangerous and life-threatening form of fungal sinusitis. Endoscopically, (when we look with a small scope in the nose) areas of dead tissue and black scabs are noted. This is because the fungus infiltrates into the tissues and blood vessels causing tissue to die in a rapidly progressive manner. Treatment involves a combination of aggressive surgical and medical therapy. Repeated surgery may be necessary to remove all dead tissue. Medications such as anti-fungal drugs and those that help restore the immune status of the patient are key to improving survival, as this disease is frequently fatal. In diabetic patients, getting the blood sugar levels under tight control is a critical aspect of managing these patients and improving their outcome.