Dermatomyositis Gottron’s sign: This sign is seen in about 70% of dermatomyositis. It presents as a reddish-purple maculopapular rash on the skin at the metacarpophalangeal and proximal phalangeal joints, flattened on the top surface with a little desquamation, with prolonged skin atrophy and hypopigmentation. Stiff capillary dilatation and petechiae are seen in the nail root crease, which helps in the diagnosis. This sign was first described by Gottron in 1930 and is considered to be an idiosyncratic rash of DM. Flat purplish papules with furfuraceous scales and well-defined borders on the extensor aspect of the digits, metacarpophalangeal joints are seen in 30% of patients, leaving atrophy, hypopigmentation and capillary dilatation after the lesions fade. Dermatomyositis (DM), also known as cutaneous heterochromic dermatomyositis, is an autoimmune connective tissue disease. Dermatomyositis can exist alone or overlap with other autoimmune diseases such as systemic lupus erythematosus, scleroderma, and rheumatoid. Patients often have a variety of specific antibodies in their blood such as anti-PM-1, anti-Jo-1, and anti-Mi-2. Dermatomyositis is a non-purulent inflammatory lesion involving mainly the transverse muscles with a predominantly lymphocytic infiltrate and may or may not be associated with a variety of skin lesions. It is characterized clinically by symmetrical weakness of the limb girdle, cervical and pharyngeal muscles, often involving multiple organs, and may be associated with tumors and other connective tissue diseases. Gottron’s sign is caused by dermatomyositis, which is its clinical cutaneous symptom. The exact etiology is not well understood and may be due to viral infection, abnormal recognition of the self by the immune system and vasculopathy, which may be interrelated. Dermatomyositis is generally considered to be related to genetic and viral infections. There are significant racial differences in the development of polymyositis and dermatomyositis. The incidence of dermatomyositis in children is higher in Asia and Africa than in Europe and the United States. The presence of dermatomyositis in identical twins and first-degree relatives also suggests a genetic predisposition. Dermatomyositis is a non-purulent inflammatory lesion involving mainly the transverse muscles with a predominantly lymphocytic infiltrate and may or may not be associated with a variety of skin lesions. It is characterized clinically by symmetrical weakness of the limb girdle, cervical and pharyngeal muscles, often involving multiple organs, and may be associated with tumors and other connective tissue diseases. The following factors have been identified: genetic susceptibility factors, autoantibodies to nuclear antigens (ANA) and cytoplasmic antigens, infectious agents, pharmacogenesis, and silicone breast implants.