Supplementary Material for: Calciphylaxis Mimicking Giant Cell Arteritis: A Case Report

<b><i>Introduction:</i></b> Calciphylaxis is a condition that causes vascular calcification and intimal proliferation with thrombotic occlusion of small-to-medium-sized vessels. <b><i>Case Presentation:</i></b> We describe a case of a 64-year-old woman who presented with a clinical picture that was suggestive of anterior arteritic ischemic optic neuropathy due to giant cell arteritis (GCA), but was found to have calciphylaxis confirmed by histologic examination. When calciphylaxis affects the blood supply to the eye, commonly it causes sudden vision loss, pallid optic disk edema, and a relative afferent pupillary defect, all of which were observed in our patient. <b><i>Conclusion:</i></b> There is no known cure for calciphylaxis, while in GCA, high-dose corticosteroid therapy is essential to prevent involvement of the contralateral eye. As the management approaches for these two diseases are different, it is important to have performed a thorough clinical examination along with detailed histopathological testing to rule out calciphylaxis of the temporal artery in patients suspected to have GCA.