Course and treatment of severe osteoporosis complicated by calciphylaxis: a case report.

Calciphylaxis, also known as calcific uremic arteriolopathy (CUA), is a rare disorder with many unknown treatment and diagnostic aspects. It is characterized by calcification and thrombosis of small blood vessels. This disease leads to progressive skin calcification, necrotizing ulcers, and infections and is associated with a high mortality rate. Although primarily affected sites tend to be on skin, those affecting bones are also significant. We report a case of CUA complicated with rapidly progressing multiple vertebral fractures and severe osteoporosis. The patient experienced a series of five vertebral fractures within 5 months after hospitalization, and blood tests revealed abnormally high levels of bone resorption marker bone-type tartrate-resistant acid phosphatase (TRACP-5b). Consequently, intravenous sodium thiosulfate and hyperbaric oxygen therapy were administered for the treatment of skin lesions caused by calciphylaxis, and brace therapy and denosumab treatment were initiated for vertebral fractures. This approach rapidly decreased TRACP-5b levels and arrested the chain of vertebral fractures. We concluded that to maintain the quality of life of patients with CUA, early treatment of primary skin lesions as well as comorbid conditions is essential.