The records of 71 young people with juvenile dermatomyositis followed for at least two years by the Paris Reference Center for Rare Pediatric Rheumatism and Autoimmune Systemic Diseases (RAISE) were retrospectively analyzed:
- five had hip, knee, and/or ankle pain associated with multiple foci of osteonecrosis in four and unilateral femoral head osteonecrosis in the fifth on MRI; four had elevated interferon α2 ;
- there was no statistically significant difference in cumulative corticosteroid dose during the first 6 months of treatment between those with osteonecrosis and those without;
- all patients with osteonecrosis had anti-MDA5 antibodies, whereas those without osteonecrosis were negative for anti-MDA5.
