Transient hypercalcemia in a patient with SAPHO syndrome

We here report a case of SAPHO (synovitis-acne-pustulosis-hyperostosis-osteitis) syndrome with hypercalcemia. The patient was diagnosed with SAPHO syndrome at the age of 54, because he exhibited osteitis and hyperostosis around the sternoclavicular joints and the temporomandibular joints bilaterally and had past medical history of palmoplantar pustulosis. At the age of 67, he exhibited appetite loss and nausea. Corrected serum calcium was 13.0 mg/dl. Adequate hydration was recommended, and his calcium levels returned to the normal range without any medical treatment. Although speculative, his hypercalcemia was considered to be caused by an increased bone activity in SAPHO syndrome. This is the first report describing transient hypercalcemia in a patient with SAPHO syndrome.