A Rare Case of Dermatomyositis with Hyponatremia

Dermatomyositis is a rare type of inflammatory myopathy that represents the largest group of acquired and potentially treatable cause of skeletal muscle weakness. It is characterized by chronic muscle inflammation accompanied by muscle weakness. Here, we present a case of an elderly female who presented with a history of pain in bilateral arm, forearm, thigh, and leg associated with swelling and with a history of rash over the upper extremities. On examination, edema with tenderness was present on both upper limb and lower limb. We also noticed erythematous rash over the arm, forearm, nose, and forehead. Investigations showed hyponatremia, with elevated Cretatinc phosphokinase levels. Hence, a provisional diagnosis of hyponatremia-induced rhabdomyolysis was made. On further evaluation, urine for myoglobin was negative, and in view of the accompanying rash and minimal improvement with sodium correction a provisional diagnosis of dermatomyositis with hyponatremia/hyponatremia-induced rhabdomyolysis was made. Diagnosis of dermatomyositis was confirmed by the muscle biopsy. Dermatomyositis may be accompanied by hyponatremia and atypical rash. It can also be confused with hyponatremic rhabdomyolysis. Dermatomyositis is also a rare presentation and it may be a paraneoplastic manifestation. How to cite this article HAK, V Vikranth. A Rare Case of Dermatomyositis with Hyponatremia. J Med Sci 2015;1(3):58-59.