Groton's sign is seen in?

Dermatomyositis REF: Harrison's 17th e chapter 382 Dermatomyositis DM is a distinctive entity identified by a characteristic rash accompanying, or more often preceding, muscle weakness. The rash may consist of a blue-purple discoloration on the upper eyelids with edema heliotrope rash a flat red rash on the face and upper trunk Erythema of the knuckles with a raised violaceous scaly eruption Gottron's sign. The erythematous rash can also occur on other body surfaces, including the knees, elbows, malleoli, neck and anterior chest (often in a V sign), or back and shoulders (shawl sign), and may worsen after sun exposure.