IFS patients have a statistically significantly higher risk for developing orbital complications if they had headache (OR 16.8, 95% CI 2.66 to 106.14, p = 0.002) or fever (p < 0.001), sphenoid (OR 21.88, 95% CI 3.295 to 145.28, p = 0.001), or posterior ethmoid sinus (OR 14.0, 95% CI 1.23 to 158.84, p = 0.035) involvement, CRP level ≥ 1.025 mg/dL (OR 88.0, 95% CI 4.76 to 1627.7, p < 0.001) or ESR level ≥ 46.5 mm/h (OR 15.0, 95% CI 1.65 to 136.17, p = 0.019). This evidence concerns the gene ESR1 and congenital fibrosarcoma.