Causes and risk factors
There are more cases among female representatives. It occurs at a young adulthood, with dermatomyositis there is also a children's form. Quite often, dermatomyositis in adults is associated with the presence of neoplasms.
The cause of the inflammation is unknown.
Which are the symptoms?
Symptoms are severe muscle weakness, especially of the arms and thighs, sometimes accompanied by pain, sometimes even fever and joint damage with arthralgia and arthritis. Less commonly, heart problems are manifested by rhythm disturbances and rarely heart failure. Damage to the lung leads to organ fibrosis. Tests usually show changes in muscle enzymes (CK, aldolase).
In the case of dermatomyositis, the skin is also involved with:
- lesions mainly represented by purplish erythema on the face, especially around the eyes;
erythematous lesions infiltrating the extensor surface of the elbows, knees, metacarpophalangeal and proximal interphalangeal joints.
How is it diagnosed?
The diagnosis is based on electromyography and muscle biopsy which show alterations related to muscle suffering. The histological examination shows inflammation of the muscle tissue, with lymphocyte infiltrate, degeneration and necrosis of the myofibrils. The characteristic autoantibodies (anti-Jo1) can help in the diagnosis, when present.
How is it treated?
With the help of cortisone, often in combination with immunosuppressants (azathioprine, methotrexate). Dermatomyositis skin lesions are sometimes treatable with synthetic antimalarial agents (hydroxychloroquine).