Dermatomyositis is a rare autoimmune disease that affects the muscles and skin. It is characterized by inflammation in the muscles, leading to muscle weakness and stiffness, as well as skin rashes. Dermatomyositis is believed to involve a combination of genetic, environmental, and immunological factors.
One of the primary symptoms of dermatomyositis is muscle weakness, particularly affecting the muscles closest to the trunk of the body, such as those in the hips, thighs, shoulders, upper arms, and neck. This weakness can lead to difficulties in everyday activities like climbing stairs, lifting objects, or raising the arms. Another characteristic feature is a distinctive skin rash, often appearing on the face, eyelids, knuckles, elbows, knees, chest, and back. The rash may present as red or purple patches (the rash on chest and back form a characteristic “shawl sign”), reddish-brown discoloration, small blood vessels, and thinning of the skin over the outer thighs, known as “holster sign.” Other symptoms include a reddish-purple discoloration on the eyelids (heliotrope rash), or raised, scaly patches (Gottron papules) on the knuckles. Additionally, dermatomyositis can include difficulty swallowing, joint pain, fatigue, fever, and nail abnormalities.
Gottron Papules
Gottron papules are a characteristic skin manifestation associated with dermatomyositis. These papules typically appear as raised, reddish-purple or violaceous bumps or patches on the skin overlying the joints, such as the knuckles. In individuals with darker skin, healthcare professionals may need to carefully evaluate the skin and use additional diagnostic techniques to accurately identify Gottron’s papules and differentiate them from other skin conditions.
Heliotrope Rash
Heliotrope rash is adistinctive skin manifestation that typically appears on the upper eyelids and can extend to the surrounding areas of the eyes and face. The rash may present as flat or slightly raised patches of discolored skin. In some cases, there may be accompanying swelling, tenderness, or a puffy appearance of the eyelids.