Hypocalcemic myopathy secondary to hypoparathyroidism

Myopathy is a rare manifestation of idiopathic hypoparathyroidism. We report a 48-year-old man with a 6-year history of muscle pain and elevated creatine kinase levels. Laboratory analysis revealed low serum calcium, inappropriately low-normal parathyroid hormone, elevated phosphorus, and normal 25-hydroxy vitamin D levels. The patient was diagnosed with idiopathic hypoparathyroidism and treated with calcium and calcitriol. He demonstrated an excellent clinical response and creatine kinase values returned to normal. This case illustrates the subtle nature of hypoparathyroid myopathy and highlights the importance of measuring serum calcium in patients with unexplained myalgia and/or muscle weakness.