Part of antisynthetase syndrome.
Condition is represented by inflammatory muscle disease, interstitial lung disease, Raynaud phenomenon, arthritis, and cutaneous manifestations, a constellation of features that are seen in about 30% of patients who have polymyositis or dermatomyositis.
Not all features need to be present to have the syndrome.
Seen frequently in antisynthetase syndrome.
Patients have cracking and fissuring on the radial side of the digits and the palms.
Often there is increased pigmentation along the palm creases that resembles the look of hands of a mechanic who just wiped the grease off his hands but did not remove the grease in the creases of the palms.
The disorder shows antibody positivity to histidyl-tRNA synthetase (anti-Jo1 antibodies).
Electrodiagnostic testing confirms the diagnosis of an inflammatory myopathy affecting the proximal muscles, and muscle biopsy confirms the diagnosis.
CPK levels may be elevated
The differential diagnosis includes autoimmune disorders that may present with muscle inflammation and skin manifestations.
The differential diagnosis includes autoimmune disorders that may present with muscle inflammation and skin manifestations: Systemic lupus erythematosus, mixed connective-tissue disease, overlap syndrome, HIV and hepatitis C.
Myositis-specific antibodies appear to have correlation with the histopathological changes seen on muscle biopsy specimens.
Initial treatment for patients with inflammatory autoimmune myopathies consists of high-dose corticosteroids.
The CPK level usually begins to drop within the first week, and muscle strength usually begins to improve several weeks after therapy with corticosteroids is started.
Corticosteroid-sparing agents often are added and include azathioprine and methotrexate.
Other helpful agents include intravenous immunoglobulin, antimalarials, cyclosporine, tacrolimus, mycophenolate mofetil, cyclophosphamide and Rituximab.