French researchers report the clinical and histological data and immunological profile of 26 patients diagnosed with granulomatous myositis:
- the age of onset was generally very late (median age 65), with clinical severity observed in half the cases,
- in 14 out of 26 cases, the etiology was sarcoidosis, and more rarely other causes (inclusion myositis, paraneoplastic syndrome),
- corticosteroid therapy was usually effective, but two-thirds of patients suffered a relapse, usually requiring second-line treatment with methotrexate.
For the authors, marked amyotrophy and distal involvement are the hallmarks of severe forms of granulomatous myositis.
