Red, thickened, scaly skin over the knuckles (Gottron's sign) associated with dermatomyositis, an autoimmune disease of the skin and muscles.

This photograph demonstrates the sign "heliotrope eyelids" in which the eyelids develop a brown (violaceous - rather than red) color. Heliotrope eyelids and Gottron's papules on the knuckles are characteristic findings in dermatomyositis.

The appearance of purple (violaceous) plaques on the knees may be associated with dermatomyositis. Typically, most lesions associated with other diseases are red (erythematous).

This is Gottron's sign, seen in dermatomyositis (an inflammatory disease of the muscles and skin). Violet-colored inflammation over the knuckles is an important diagnostic finding in dermatomyositis, since other skin conditions produce more redness.

This is a picture of microscopic polyarteritis on the shin. The term polyarteritis means that many blood vessels are inflamed. These nodules are located just below the skin's surface (subcutaneous), are barely felt when pressing on the skin (palpable), and are tender. The skin is typically red (erythematous).

This is a picture of a systemic lupus erythematosis rash on the face. Lupus erythematosis often produces a "butterfly rash" or malar rash. Typically, the rash also appears on the nose.