Orbital myositis in systemic lupus erythematosus: a case-based review.

Ocular complications occur in up to one-third of patients with systemic lupus erythematosus (SLE). Among them, orbital myositis (OM) is considered a rare manifestation that affects the extraocular muscles and causes pain and restriction with eye movement. We report a case of OM in a 48-year-old female with SLE and secondary Sjogren's Syndrome, who presented headache, periorbital edema, and painful ocular movements in both eyes, with no other systemic manifestations. An orbital magnetic resonance image revealed thickening of the right medial rectus and left lateral rectus muscles. Laboratory tests were normal and there was no further disease activity. The patient was treated with prednisone 1 mg/Kg/day with a resolution of symptoms. We found 13 additional cases of OM from our literature review (11 SLE patients and 2 with discoid lupus erythematosus). There was a female predominance in these cases with a mean age of 43.6 years (SD ± 16.9). Their main clinical features included eye pain, swelling, proptosis, diplopia, and limitations in extraocular muscles, while in most of them, there was no other active systemic manifestation. Treatment with steroids led to the complete resolution of symptoms in most of these patients. The available evidence suggests that it is essential to have a high index of suspicion for OM in SLE patients even when there is no systemic disease activity so that proper treatment is initiated early.