Exploring Demographic Characteristics and Clinical Manifestations of Skull Base Osteomyelitis: A Comparative Analysis of Two Academic Hospital Systems

Background: Skull base osteomyelitis (SBO) is a rare, life-threatening infection with significant potential co-morbidities. Because of our experience managing SBO among a diverse patient population, we aimed to evaluate how clinical and demographic characteristics impact risk of SBO diagnosis between different healthcare settings. Methods: A retrospective case-control study was performed with aggregate patient electronic health data from 2000-2025 at two urban healthcare institutions: a private academic center (Institution-A) and a public, safety-net hospital (Institution-B). Adult patients with SBO were identified through ICD coding and compared against adults without SBO ICD codes. Odds ratios evaluated the effect size of SBO diagnosis and association among demographics, co-morbidities, and symptomatology. Results: Institution-A had 351 cases and 4,309,144 controls. Institution-B had 539 cases and 4,067,562 controls. The odds of SBO diagnosis were significantly higher at Institution-B vs. Institution-A (OR 1.63, 95% CI 1.42-1.86). Otologic symptoms and/or otitis media were strong predictors of an SBO diagnosis across both institutions (Tables 1 and 2). Female patients, patients with BMI ≥ 30 kg/m 2 , and patients of Hispanic/Latino ethnicity had significantly increased odds of diagnosis ( Table 3 ). Institution-B, however, demonstrated a significantly stronger association for Hispanic/Latino ethnicity and history of MI, atrial fibrillation, and hyperlipidemia compared to Institution-A. Payor mix varied between institutions ([ Fig. 1 ]). Table 1 Co-morbidities associated with SBO diagnosis Institution-A Institution-B T2DM 17.97***[14.56-22.16] 18.73***[15.81-22.18] CKD 10.00***[7.41-13.25] 14.30***[11.35-17.82] Hypertension 10.89***[8.83-13.44] 14.12***[11.87-16.82] Stroke 5.61***[2.79-9.95] 9.70***[6.52-13.83] MI 3.63***[1.80-6.43] 9.79***[7.63-12.38] Atrial Fibrillation 3.16***[1.80-5.10] 6.38***[3.84-9.89] Otitis Media 79.03***[63.78-97.67] 75.02***[63.35-88.87] HIV 7.48***[3.97-12.69] 6.84***[4.33-10.21] Hyperlipidemia 11.28***[9.13-13.92] 19.47***[16.34-23.26] Table 2 Symptomatology associated with SBO diagnosis Institution-A Institutition-B Hearing Loss 30.15***[23.99-37.66] 46.82***[39.19-55.77] Dizziness 13.72***[10.71-17.40] 16.43***[13.71-19.61] Otorrhea 214.18***[158.36-284.16] 211.52***[167.68-263.94] Otalgia 98.40***[79.45-121.58] 109.58***[92.42-130.09] Facial Nerve Disorders 24.56***[14.26-39.18] 23.63***[16.20-33.20] Table 3 Demographics associated with SBO diagnosis Institution-A Institution-B BMI ≥30 vs. BMI ≥18.5 to