A rare case of orbital inflammation complicated by hemophagocytic lymphohistiocytosis.

We report a rare case of orbital inflammation complicating hemophagocytic lymphohistiocytosis (HLH) patient. HLH is a rare, life-threatening disorder characterized by uncontrolled activation of cytotoxic T lymphocytes, natural killer cells, and macrophages. A 37-year-old man known to have HLH, presented with a left periorbital swelling that was unsuccessfully treated as an orbital cellulitis, with intravenous antibiotics. A computed tomography (CT) scan of the orbits revealed inflammatory changes with no orbital collection or paranasal sinus disease. An orbital biopsy demonstrated lymphoplasmacytic infiltrations admixed with histiocytes. The patient deteriorated and was admitted to the intensive care unit. Ensuing blood results supported a diagnosis of HLH, and the patient responded well to subsequent immunosuppression. This case report highlights the importance of re-considering the diagnosis of orbital cellulitis in treatment resistant cases, particularly in the absence of sinus disease. To our knowledge, this is the third case of orbital inflammation associated with HLH patients.