Clinical analysis of 50 children with juvenile dermatomyositis.

Objective: We performed a retrospective review of medical records to assess the clinical characteristics of 50 Japanese children with juvenile dermatomyositis (JDM).
Methods: Fourteen boys and 36 girls who visited Yokohama City University Hospital between 1983 and 2008 were enrolled. Gender, age at disease onset and diagnosis, presenting clinical features, laboratory data at onset, complications, treatment, and outcome were reviewed.
Results: Mean age at disease onset was 6.9 years. Clinical manifestations at the first visit were muscle pain and/or weakness (90 %), malar rash (90 %), Gottron's papules (86 %), and heliotrope rash (80.0 %). Elevated serum levels of creatine kinase were found in 57.0 % of patients and aldolase in 95 %. T2-weighted magnetic resonance (MR) images with fat suppression demonstrated positive findings in 89.5 % of patients. Initial treatment was prednisolone (PSL) orally or pulsed methylprednisolone (mPSL) i.v. Pulsed mPSL therapy showed efficacy superior to PSL [flare in 8 of 19 (42 %) vs. 18 of 25 (72 %)]. Children refractory to initial treatment were given additional pulsed mPSL and/or cyclophosphamide (IVCY; n = 19) i.v.. Four patients with interstitial pneumonia responded well to IVCY.
Conclusions: Our findings support the notion that JDM might be considered as both a systemic inflammatory and noninflammatory vasculopathy best treated by IVCY, as shown in previous literature.