Long-standing and poorly controlled disease in juvenile dermatomyositis is associated with calcinosis: a real-world experience from a low-middle income country.

To study the prevalence and predictors of calcinosis in Juvenile Dermatomyositis (JDM). Medical records over 20 years at a tertiary care rheumatology center in Northern India were reviewed to identify patients with JDM and clinical details were recorded. The frequency of calcinosis, predictors, specific treatment, and its outcomes were studied. Data are expressed as median and interquartile range. In eighty-six patients (median age 10) of JDM, the frequency of calcinosis was 18.2% (8.5% at presentation). Younger age at presentation, longer follow-up, heliotrope rash [Odds Ratio (95% confidence interval), 11.4 (1.4-92.12)], chronic or polycyclic course [4.4 (1.2-15.5)] and cyclophosphamide use [8.2 (1.6-41.9)] were associated with calcinosis. Dysphagia [0.14 (0.02-1.2)] and elevated muscle enzymes [0.14 (0.04-0.5)] were negatively associated with calcinosis. Treatment with pamidronate had a good to moderate response to calcinosis in five of seven children. Calcinosis in JDM is associated with long-standing, poorly controlled disease, and the use of bisphosphonates like pamidronate offer promise in the future for its treatment.