LAUSR

Letter to the Editor We read with interest the article by Savino et al. about three patients with alleged orbital myositis following vaccination with an RNA-based anti-SARS-CoV-2 vaccine. The previous history was positive for ANCA-positive vasculitis in patient-1 (64yo female), for Hashimoto thyroiditis in patient-2 (58yo female), and was uneventful for patient-3 (45yo female). The study is appealing but raises concerns that should be discussed. Contrary to what is stated in the abstract, contrast-enhanced MRI was not performed in each patient. Description of patient-1 does not include the results of MRI with contrast medium. There is also no mentioning of contrast medium application in the caption of figure 1, showing the orbital MRI of patient-1. Even more disturbing is that patient-2 did not undergo MRI of the orbita at all, as there is neither a description of this investigation nor a figure that shows the pathology. Furthermore, patient-3 had undergone MRI of the orbita with contrast medium showing enlargement of the extra-orbital muscles but no enhancement. Diagnosing orbital myositis without documenting enhancement if the extra-ocular muscles is not allowed. The discrepancy between the abstract and the case presentation should be explained. Based on the presented data, the diagnosis orbital myositis remains questionable in all three patients. Because patient-1 had ANCA-positive vasculitis and because ANCA-positive vasculitis can be complicated by orbital myositis, it cannot be ruled out that the described abnormalities of the extra-orbital muscles (enlargement of all right rectus muscles) was due to vasculitis rather than the vaccination. A further discrepancy refers to the statement that patient-1 had no systemic symptoms and the diagnosis ANCA-positive vasculitis. The reader should be informed how ANCA-positive vasculitis manifested clinically and which treatment patient-1 received for this disease. Particularly, we should know if the patient was on a long-term treatment with any biological or TNF-receptor analogue. From ipilimumab and etancercept it is known that they can be complicated by orbital myositis. Regarding patient-2, the reader should know if fever and lymphadenopathy was already present prior to the vaccination or not. It is also crucial to know the levels of TPO-antibodies, thyreoglobulin antibodies, TSH-receptor antibodies, or thyroidea stimulating immunoglobulin antibodies. Hashimoto thyroiditis is usually characterised by elevation of at least some of these antibodies. There is a discrepancy between the history of patient-2 (Hashimoto) and the results of the serological tests, which excluded thyroid disease. We should know if these antibodies were determined or not. Why did patient-3 attend the ophthalmologic department not earlier than three months after onset? How can myositis still be present after three months? Did the patient receive any treatment in the meantime? We disagree with the statement that the patients are the first reported with orbital myositis after RNA-based antiSARS-CoV-2 vaccines. Post-vaccination orbital myositis has been previously reported.