Orbital myositis in systemic lupus erythematosus

Dear Editor,

With great interest, I read the article titled “Orbital myositis in systemic lupus erythematosus: A case report and literature review,” written by Chan et al. (1), which was published in a recent issue of the European Journal of Rheumatology, and I would like to discuss the results further in light of recent findings in this field. I wish to contribute to this case report by providing information regarding our published case (2).

The importance of imaging in orbital myositis (OM) is clear as described by the authors, and a diagnosis was made on the basis of the patient’s clinical presentation and imaging findings; however, it would have been interesting to perform the evolutionary computed tomography (CT) scan after the improvement of the patient and to discuss the choice between CT and magnetic resonance imaging.

OM is a diagnostic challenge, seen as a subgroup of orbital pseudotumor syndrome, which involves the extraocular muscle predominantly, owing to an inflammatory process (2). It often presents as an acute idiopathic onset with painful diplopia in young adult women along with dysfunction of the extraocular muscle and usually responds to a course of oral corticosteroids. It is an inflammatory disorder, which, after extensive etiological investigation, is revealed to be idiopathic in most patients but also occurs in the context of specific autoimmune, inflammatory, and infectious conditions (3). The major differential diagnoses are thyroid ophthalmopathy, orbital cellulitis, and orbital lymphangioma.

In their description, the authors stated that extensive investigations were performed to rule out all other possible causes of myositis, and it would be interesting to make it clear that autoimmune and inflammatory disease, such as systemic lupus erythematosus. In their description, the authors claim that an extensive investigation was carried out to rule out all other possible causes of myositis, it would be interesting for readers to make it clear that autoimmune and inflammatory diseases such as systemic lupus erythematosus were investigated.

In a recent review, McNab (3) proposed a new and practical classification system OK that could help in a better understanding of OM, allowing for a more homogeneous language for future research reports, facilitating both specialists and residents, and serving as a framework for reporting future research.

I congratulate the authors for an excellent and very well-structured report that emphasizes the importance of anamnesis, inspection, physical examination, and correct indication of complementary tests for good clinical recognition, especially for rare diseases.