Mucormycosis also may affect other parts of the body, including the lungs, GI tract, or skin. The spores of these fungi are ubiquitous and gain entrance to the human body through the mouth and nose. Mucormycosis is described almost exclusively in patients with compromised immune systems or metabolic abnormalities. Spread occurs when it invades the nasal cavity and maxillary sinuses. Extension to ethmoid sinuses can lead to orbital involvement.
Intracranial spread can occur through the ophthalmic artery, superior fissure, or cribriform plate.
Areas of ischemic infarction and necrosis are seen in the infected tissue. The fungi invade the blood vessel lumina and cause thrombosis through inflammatory occlusion. Diabetic patients are predisposed to mucormycosis because of the decreased ability of their neutrophils to phagocytize and adhere to endothelial walls. Furthermore, the acidosis and hyperglycemia provide an excellent environment for the fungus to grow. Despite advances in diagnosis and treatment, a high mortality still exists for this disease.