Refractory Orbital Myositis in Systemic Lupus Erythematosus A Role for Rituximab

Orbital myositis in systemic lupus erythematosus (SLE) is a rare entity with risk of serious complications. Timely treatment with effective immunosuppressors is desirable. We report a case of a 32-year-old female patient with SLE who presented with an acute ocular pain and extraorbital muscle thickening, consistent with orbital myositis. Association with SLE was made after exclusion of other aetiologies. Due to refractoriness to steroids, off-label rituximab was initiated with clinical and imaging parameter improvement. LEARNING POINTS: Orbital myositis is a rare entity that can be present in some autoimmune diseases or mimic other common ocular conditions, such as orbital cellulitis or thyroid orbitopathy. In SLE, it may be the form of presentation of the disease or the only manifestation of active disease, even without elevation of inflammatory biomarkers. Generally, patients with orbital myositis have an excellent response to high-dose corticosteroid therapy, but the risk of recurrence or refractoriness is not negligible.