Beyond the danger triangle: Septic cavernous sinus thrombosis following a temporal forehead furuncle.

Septic cavernous sinus thrombosis (CST) is a rare but life-threatening complication of facial infections, typically arising from the midface 'danger triangle'. Rarely, lateral facial infections may also lead to CST through spread via deep venous pathways. We report a previously healthy adolescent boy who developed fever, bilateral orbital swelling, and painful ophthalmoplegia shortly after the resolution of a furuncle over the left temporal part of the forehead. Magnetic resonance imaging confirmed CST. He was treated with intravenous ceftriaxone, vancomycin, and low molecular weight heparin, resulting in clinical recovery. This case highlights the importance of considering CST even when the primary infection lies outside the classical anatomical danger zone.