Painless bilateral orbital myositis during a multisystem flare of systemic lupus erythematosus: Case report and focused literature review.

BackgroundOrbital myositis (OM) is an uncommon ocular manifestation of systemic lupus erythematosus (SLE) and is typically characterized by acute painful proptosis and diplopia. Only isolated painful cases have been documented, and these usually occur without systemic activity.CaseA 44-year-old woman with a six-year history of SLE developed painless bilateral proptosis and mild abduction restriction during a severe multisystem flare involving the kidneys, lungs, and gallbladder. Laboratory studies revealed high anti-dsDNA titres, hypocomplementemia, and elevated inflammatory markers. Orbital computed tomography demonstrated isolated enlargement of both lateral rectus muscles without evidence of infection, sinus disease, or thyroid orbitopathy. She received intravenous methylprednisolone 1000 mg daily for 3 days, followed by an oral prednisone taper (1 mg/kg/day) and intravenous cyclophosphamide 1000 mg every 4 weeks for six pulses. Both ocular and systemic manifestations resolved within 24 hours of initiating pulse therapy. During admission, she developed acalculous cholecystitis, attributed to active lupus vasculitis after multidisciplinary assessment.ConclusionThis represents the first reported case of painless orbital myositis associated with systemic lupus erythematosus during a multi-systemic flare. Rapid response to corticosteroid and cyclophosphamide therapy underscores the inflammatory, reversible nature of this manifestation. Recognition of OM as a potential lupus complication is critical for prompt diagnosis, exclusion of infectious causes, and early initiation of aggressive immunosuppression to preserve vision and prevent systemic morbidity.