What is the workup for Chronic Fungal Sinusitis (Chronic Fungal Sinus Infection)?

From the Guidelines

The workup of chronic fungal sinusitis should prioritize a comprehensive approach including clinical evaluation, imaging, and microbiological testing to ensure accurate diagnosis and effective management, as outlined in the European position paper on rhinosinusitis and nasal polyps 2020 1. The initial assessment should include a thorough history focusing on symptoms like nasal congestion, facial pain, headache, and discharge, along with risk factors such as immunocompromise or previous sinus surgery.

• Key symptoms to investigate include:
  • Nasal congestion
  • Facial pain
  • Headache
  • Discharge
• Risk factors to consider:
  • Immunocompromise
  • Previous sinus surgery Physical examination should include anterior rhinoscopy and nasal endoscopy to visualize fungal debris, mucosal changes, and polyps.
• Imaging studies are crucial, with CT scanning of the sinuses essential to evaluate the extent of disease, bony erosion, and opacification patterns, while MRI may be considered if complications or invasive disease are suspected, as recommended by the ACR Appropriateness Criteria for sinonasal disease 1.
• Microbiological confirmation is crucial through collection of sinus secretions, debris, or tissue samples for fungal culture, histopathology with special stains (PAS, GMS), and possibly fungal PCR.
• Laboratory tests should include complete blood count, immunoglobulin levels, and specific tests for allergic fungal sinusitis such as total IgE, fungal-specific IgE, and eosinophil count. Management typically involves surgical debridement via functional endoscopic sinus surgery to remove fungal material and improve sinus drainage, followed by appropriate antifungal therapy based on the specific type of fungal sinusitis identified, with voriconazole being a recommended option for Aspergillus species 1. For allergic fungal sinusitis, treatment includes corticosteroids (oral prednisone starting at 0.5mg/kg/day with taper over 2-3 weeks, plus intranasal steroids like fluticasone 2 sprays twice daily), while invasive forms require systemic antifungals such as voriconazole 200-300mg twice daily or amphotericin B formulations.
• Regular saline irrigations and follow-up endoscopic examinations are essential for monitoring response to treatment and detecting recurrence.

From the Research

Diagnosis of Chronic Fungal Sinusitis

• The diagnosis of chronic fungal sinusitis can be challenging, and a combination of histology, culture, and molecular tests such as polymerase chain reaction (PCR) may be necessary for accurate diagnosis 2.
• Histopathology is the gold standard for diagnosis, but negative histopathologic findings do not rule out the disease, and fungal DNA detection can be a useful complement to histology and culture 2.

Clinical Presentation and Comorbidities

• Chronic invasive fungal sinusitis (CIFS) is a rare disease characterized by a slow onset and invasive organisms with non-granulomatous inflammation seen on histopathology 3.
• Patients with CIFS often have systemic comorbidities, such as diabetes mellitus, and may present with nonspecific symptoms such as facial pressure, headache, and nasal obstruction 3, 4.

Imaging Studies

• Imaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) can aid in the diagnosis of fungal sinusitis, with CT being superior for detecting bony erosion and hyperdense fungal elements, and MRI excelling in evaluating soft tissue and mucosal involvement 5.
• Key radiologic signs such as bone destruction, sinus wall thickening, and 'black turbinate sign' can aid in early diagnosis, especially in invasive cases 5.

Histologic Spectrum and Correlation with Culture

• Fungal sinusitis can be categorized into different histologic types, including allergic fungal sinusitis, mycetoma/fungus ball, chronic invasive fungal sinusitis, and acute fulminant fungal sinusitis 6.
• The diagnosis of fungal sinusitis can be missed or incorrectly classified, highlighting the importance of awareness of the distinctive morphologic features of this entity 6.

Workup and Treatment

• The workup for chronic sinusitis includes a combination of history, physical examination, nasal cytology, and imaging studies such as CT and MRI 4.
• Treatment of CIFS may involve long-term antifungal therapy and conservative endoscopic surgery, with the goal of eradicating the fungal infection and preventing complications 3.