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: Dental
Groton's sign is seen in 
Select and explain. 
A. Dermatomyositis, B. SLE, C. Scleroderma, D. MCTD
A: Dermatomyositis
Answer: A: Dermatomyositis 
Explanation: Another form the rash takes is called Gottron's sign which are red or violet, sometimes scaly, slightly raised papules that erupt on any of the finger joints (the metacarpophalangeal joints or the interphalangeal joints). The most common signs and symptoms of dermatomyositis include: Skin changes. A violet-colored or dusky red rash develops, most commonly on your face and eyelids and on knuckles, elbows, knees, chest and back. The rash, which can be itchy and painful, is often the first sign of dermatomyositis Ref Harrison20th edition pg 1232