Multidisciplinary Approach to Severe Intracranial, Intraorbital Allergic Fungal Sinusitis

Background: Allergic fungal sinusitis (AFS) is a form of paranasal mycosis that often involves bone destruction and extension into the orbit and anterior skull base. Treatment consists of surgery; medical therapy with oral steroids, topical steroids, and antibiotics; as well as immunotherapy. Reports of intracranial involvement and intraorbital involvement are published but not both in each included patient of a series.

Methods: The records of 31 patients with the histological diagnosis of AFS and both intracranial and intraorbital involvement were reviewed. The histological diagnosis was based on findings of branching septated fungi interspersed with eosinophilic mucin and Charcot-Leyden crystals without fungal invasion of soft tissue.

Results: The average age of the patients in this study was 25.5 years (range: 13–51), with 36% being 18 years old or younger. 86% of patients were male. 71% were African American, and 29% were Caucasian. 64% of patients had Medicaid or were uninsured. All patients were immunocompetent. Presenting symptoms were headaches (79%), nasal obstruction (57%), proptosis (43%), vision change (21%), diplopia (7%), facial pressure (7%), and loss of sense of smell (7%). 93% of patients had nasal polyposis. 100% had erosion of bone observed on computerized tomography (CT) scans with disease extending intracranially through the anterior skull base or posterior wall of frontal sinus as well as disease that eroded through the lamina papyracea. 93% of patients had bilateral disease. All patients tried antibiotics and steroids preoperatively. All patients underwent surgery by Otolaryngology, Ophthalmology, and Neurosurgery. They all underwent transnasal endoscopic approaches and orbitotomy. 79% also underwent a bifrontal craniotomy for removal of intracranial extradural disease. 50% of patients had orbital implants left in place after surgery (45% bilateral, 55% unilateral). 21% of patients had nasal stents left in place after surgery. No patient had a postoperative cerebrospinal fluid leak. Average hospital stay was 4.9 days. Preoperatively, all patients had tried oral steroids, topical nasal steroids, and oral antibiotics. Preoperatively, 14% of patients had undergone allergy testing. Postoperatively, 93% were evaluated by an Allergist. 21% needed follow-up surgery. Mean follow-up was 3.3 years.

Conclusion: Allergic fungal sinusitis is a slow growing but destructive benign disease. A team approach of otolaryngologists, ophthalmologists, and neurosurgeons is recommended. Most patients present with headaches and nasal obstruction. While most cases of chronic sinusitis can be successfully managed with transnasal endoscopic techniques, orbitotomy and craniotomy are commonly needed in the severe allergic fungal sinusitis cases with extensive intracranial and intraorbital involvement. Postoperative therapy includes Allergy evaluation. This disease is found most commonly in young African American males and in the underinsured.