BackgroundAllergic fungal sinusitis (AFS) is a form of paranasal mycosis that often involves bone destruction and can extend into the orbit and anterior skull base. Intracranial and intraorbital involvement are published but not both in each included patient of a series. The purpose of the present study was to review cases of extensive AFS with orbital or/and skull base erosion, including the presenting symptoms, patient socioeconomic background, imaging features, surgical technique, and post-operative outcomes. MethodsThe records of 30 patients with the histological diagnosis of AFS and both intracranial and intraorbital involvement were reviewed. ResultsThe average age of the patients was 25.2 years. 83 % of patients were male. 70 % were African American. 66 % of patients had Medicaid or were uninsured. Presenting symptoms were headaches (80 %), nasal obstruction (33 %), proptosis (40 %), vision change (23 %), facial pressure (10 %), and decreased sense of smell (7 %). 100 % of patients had bone erosion observed on computerized tomography scans with disease extending intracranially through the anterior skull base or posterior wall of the frontal sinus along with disease that eroded through the lamina papyracea. All patients had failed medical management. All patients underwent surgery by Otolaryngology, Ophthalmology, and Neurosurgery with transnasal endoscopic approaches and orbitotomy. 80 % also underwent a bifrontal craniotomy for removal of intracranial extradural disease with cranialization. 53 % of patients had orbital implants remaining after surgery; 23 % had nasal stents. There were no postoperative cerebrospinal fluid leaks. Average hospital stay was 4.8 days. Preoperatively, 13 % of patients underwent allergy testing. 94 % saw an Allergist postoperatively. 21 % required follow up surgery. ConclusionsA team approach of Otolaryngologists, Ophthalmologists, and Neurosurgeons is recommended for this slowly growing but locally destructive disease. Most patients with AFS will present with headaches and nasal obstruction. While most cases of AFS can be successfully managed with transnasal endoscopic techniques, orbitotomy and craniotomy represents an effective treatment for severe AFS cases with extensive intracranial and intraorbital involvement. This disease is found most commonly in young African American males and in the underinsured.