This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autoimmune Skin Disorders, Subject name: Skin
Dermatomyositis test of choice - 
Select and explain. 
A. CPK, B. 24hr urine creat, C. SGOT, D. SGPT
A: CPK
Answer: A: CPK 
Explanation: Ans is 'a' i.e., CPK Investigations for Dermatomyositiso Muscle enzymes CPK Elevation (mostsensitive), aldolase elevation, myoglobin levation, 24 urinary creatine excretion.o Autoantibodies ANA antibodies, anti Jo-i (20% cases), anti- Mi-2 (5-10%)o Others ESR, RF factor, skin & muscle biopsy, EMG