A 64-year-old man is having difficulty getting out of a chair. He has lost 15 lb and feels tired all the time. On examination, there is a blue purple rash on his eyelids and knuckles, and muscle strength in his proximal muscles is rated 4 out of 5. His creatinine kinase (CK) level is elevated and he is started on prednisone. Which of the following is the most important in monitoring response to therapy?
High-Yield Explanation
The course of muscle necrosis in dermatomyositis can be best followed by repeated CK determinations. Repeated muscle biopsies are rarely required. However, the goal of therapy is to increase muscle strength and function, so following muscle strength is the key clinical assessment of response to therapy.