Sinusitis and Fungal Infections Quiz

Maxillary Sinus Diseases

• Sinusitis: Inflammation of the sinus mucoperiosteum. Often associated with ostium blockage by thickened mucosa, preventing drainage into the middle meatus. Decreased ciliary action also plays a role.
• Acute sinusitis: Commonly follows rhinovirus infections (common cold). Bacteria from the upper respiratory tract (URT) can also cause sinusitis. Streptococcus pneumoniae is the most common bacterial cause. Other bacteria include Haemophilus influenzae and Moraxella catarrhalis. Symptoms include pain and stuffiness, sinus walls tender to pressure, pain referral to maxillary molars or premolars, worse with percussion (rule out dental disease), thick nasal discharge (blood and pus in adults), fever, chills, malaise, and elevated WBC count. Radiographic features show an air-fluid level, which is a horizontal, faintly radiopaque line in the sinus representing the junction of air and fluid (mucus, blood, pus).
• Chronic sinusitis: Often a consequence of acute sinusitis, or multiple incidents of acute sinusitis can lead to chronic sinusitis. May occur without prior acute phase, with recurrent incidents lasting over 3 months. Bacteria are typically anaerobes, such as Streptococcus, Bacteroides, and Veillonella species. Radiographic features include localized thickening of mucosa, generalized thickening, and diffuse radiopacity throughout the sinus. Sinus walls are usually intact.

Odontogenic Sinusitis

• Odontogenic sinusitis: Mucositis resulting from periapical inflammation or periodontitis. Thickening and inflammation of mucoperiosteum in the sinus. May or may not present symptoms, can mimic chronic sinusitis. Pus can develop in the lesion. Accounts for 25% to 40% of chronic sinusitis cases.
• Periapical Mucositis: Inflammation and thickening of mucosa adjacent to the tooth apex, evident as a radiographic finding.
• Periapical Osteoperiostitis: "Halo" of bone can form around the tooth apex due to periosteal proliferation. This often occurs with periapical periodontitis close to the maxillary sinus.
• Radiographic features: Location is typically along the floor or inferior aspect of the sinus wall, centered over areas of periapical or periodontal inflammation. Periapical mucositis shows thickening or increased radiodensity of mucosa, and periapical osteoperiostitis shows a halo of bone around the tooth apex.

Fungal Sinusitis

• Fungal infections can lead to sinusitis, often in weakened patients with conditions like diabetes mellitus, immunosuppression (HIV/AIDS), leukemia, or those taking chronic corticosteroid therapy.
• Mucormycosis (Phycomycosis): Invasive form of fungal sinusitis, commonly in nose and sinuses, presenting with bloody nasal discharge, sinus pain, proptosis (eye bulging), and palate expansion. May cause extensive necrosis. Radiographic features reveal opacification of the sinus with possible destruction of sinus walls.
• Aspergillosis: Invasive form can affect people with poor immunity. Symptoms resembling asthma and significant pain are present, especially after dental procedures. Radiographic features indicate thickened mucoperiosteum with soft-tissue masses, often with prominent calcifications that can mimic antroliths. Microscopic examination shows septae hyphae (usually 3-4 µm).
• Note: Both Mucormycosis and Aspergillosis in the sinus can be potentially life-threatening.

Other Maxillary Sinus Diseases

• Antral pseudocyst & Mucous Retention Cyst: Serous inflammatory fluid accumulating beneath the periosteum, causing a sessile elevation of the sinus lining. Histologically, antral pseudocysts lack an epithelial lining, while Mucous retention cysts have one. Causes include inflammatory exudate or seromucinous gland blockage. Usually solitary, but mucous retention cysts can be multiple. Symptoms are usually mild, but large lesions may prolapse into the nose. Radiographic appearance shows a faintly radiopaque, homogeneous, dome-shaped mass, which is usually sessile.
• Antral polyp: A thickened mass of chronically inflamed mucous membrane, producing irregular folds or nodular masses, possibly resulting from generalized thickened mucosa. May be solitary or multiple. May cause displacement or destruction of the sinus walls. Radiographic features show a sessile mass that appears to arise from thickened sinus mucosa.
• Antrolith: Calcification of a nidus in the sinus. The nidus can be intrinsic, like stagnant mucus or a fungus ball, or extrinsic, being a foreign body. Small antroliths are often asymptomatic. Symptoms are generally present with larger lesions. Radiographic features show a solitary or multiple, faintly to extremely radiopaque mass, often well-defined, and round or oval.
• Mucocele: A lesion caused by ostium blockage (inflammatory or neoplastic), resulting in expansion of sinus walls. The sinus walls may become thinned, or perforated. Clinical features include swelling and sensation of fullness where the sinus wall is altered, possible extension through sinus walls. Radiographic features are well-defined, round or irregular, faintly radiopaque, and isodense with surrounding soft tissue. The walls may be resorbed and/or expanded and possibly perforated.

Treatment & Differential Diagnosis

• Diagnostic considerations and management for each type of sinusitis and associated entities are discussed.