Calcinosis in juvenile dermatomyositis: frequency, risk factors and outcome.

The aim was to retrospectively estimate the prevalence of calcinosis in patients with juvenile dermatomyositis (JDM) and to identify risk factors associated with development of calcinosis in these patients. Retrospective chart review of 39 children diagnosed with JDM between 2004 and 2015 in a tertiary care hospital was done. Patients were divided into two groups, depending on the presence or absence of calcinosis, and the two groups were compared with respect to demographic, clinical, laboratory and therapeutic characteristics. Calcinosis developed in nine (23.1 %) patients. Delay in diagnosis and initiation of treatment, prolonged duration of disease, the presence of joint contractures and cardiac involvement were significantly associated with increased frequency of calcinosis. Six out of nine (66.7 %) patients with calcinosis received alendronate therapy, out of which four showed partial reduction in calcinosis. In one case, surgical removal of tumorous clumps was done. Calcinosis remains a common complication of JDM. We found an association between calcinosis and delay in diagnosis and initiation of treatment, prolonged duration of disease and cardiac involvement. Our study suggests that alendronate may be beneficial in management of calcinosis of JDM.