Fungal sinusitis is an inflammation of the paranasal sinuses caused by the presence of fungi. These air-filled cavities, located around the nose and eyes, can become inflamed when fungal organisms colonize or infect them. The condition differs from more common bacterial or viral sinus infections because it involves a specific fungal etiology.
Observable Symptoms
Persistent nasal congestion, which may not improve with typical remedies for colds or allergies, is a common observation. Many people also report thick, discolored nasal discharge, which can sometimes appear dark, brownish, or even contain black specks, suggesting the presence of fungal elements. This discharge may have an unusual odor.
Facial pain or pressure is another frequently reported symptom, often localized around the cheeks, forehead, or between the eyes. Headaches can also occur, sometimes accompanied by a decreased sense of smell. In more advanced or severe cases, the visual appearance of the face might change. This can include visible facial swelling, particularly around the eyes or cheeks, and in some aggressive forms, eye bulging (proptosis) or changes in skin color, such as paleness or a darkened appearance, can develop.
How It Appears to Medical Professionals
A nasal endoscopy, which involves inserting a thin, flexible tube with a camera into the nasal passages, can reveal characteristic findings. These may include the presence of nasal polyps, thick, often discolored or “cheesy” fungal debris, or particular changes in the appearance of the sinus lining mucosa.
Imaging scans, such as computed tomography (CT) or magnetic resonance imaging (MRI), provide a detailed view of the sinus cavities and surrounding structures. On these scans, medical professionals might observe opacification, meaning the sinuses appear filled rather than air-filled, or specific patterns of fungal colonization within the sinuses. In some cases, imaging can also show evidence of bone erosion, indicating the fungus is affecting the bony walls of the sinuses.
Furthermore, direct examination of tissue samples under a microscope, known as histopathology, offers definitive visual evidence. This involves taking a small piece of tissue from the affected sinus during surgery or biopsy. Under the microscope, pathologists can identify fungal hyphae (thread-like structures) or spores, confirming the presence of a fungal infection and sometimes even identifying the specific type of fungus involved.
Distinguishing Features of Different Types
Allergic Fungal Rhinosinusitis (AFRS) often manifests with thick, tenacious mucus that can resemble peanut butter or a cheesy substance, frequently containing dark fungal elements. Patients with AFRS commonly develop nasal polyps, which are soft, non-cancerous growths within the nasal passages, and imaging scans may show heterogeneous signal intensity within the sinuses.
A Fungus Ball, also known as a mycetoma, typically appears as a dense, solitary mass of fungal hyphae and debris within a single sinus cavity. This mass is usually non-invasive, meaning it does not attack the surrounding tissues. On imaging, a fungus ball can be seen as a calcified or hyperdense lesion, often within the maxillary (cheek) sinus, and it may block the sinus drainage pathway.
In contrast, Invasive Fungal Sinusitis is characterized by its aggressive and destructive appearance, often progressing rapidly. This type can present with severe symptoms, including tissue necrosis, which is the death of tissue, and a distinctive black eschar (a scab or dry crust) on the nasal mucosa. Imaging studies for invasive forms frequently reveal aggressive bone erosion, indicating the fungus is actively invading and destroying surrounding structures.