Isaacs' syndrome in a patient with dermatomyositis: case report and review of the literature.

This is a case report of Isaacs' syndrome in dermatomyositis. The patient presented with proximal muscle weakness, rash, elevated muscle enzyme, myopathic electromyograph and typical muscle biopsy. Ultimately he developed typical symptoms of Isaacs' syndrome which is an autoimmune channelopathy from voltage gated potassium channel antibody (anti-VGKC) leading to dysfunction of axonal discharge at neuromuscular junctions. It shares some similar characteristics with dermatomyositis such as autoimmunity, its association with malignancy and the response to treatment.