Nailfold abnormality ups calcinosis risk in juvenile dermatomyositis

Children with idiopathic inflammatory myopathies who present with abnormal nailfold capillary changes at baseline are prone to the development of calcinosis, suggests a recent study.

“The long-term outcomes of juvenile dermatomyositis (JDM) are more favourable in recent years,” the researchers said. “However, calcinosis is still among the complications that can cause serious functional impairment.”

Since little is known regarding the pathogenesis and risk factors of calcinosis, the researchers sought to determine the risk factors for its development in JDM.

They conducted a single-centre, retrospective study in patients who were diagnosed and followed at the multidisciplinary JDM clinic of The Hospital for Sick Children in Toronto, Canada, from 1 January 1989 until 31 May 2018. Finally, Cox regression analysis was carried out to examine the predictors of incident calcinosis.

Overall, 172 patients (median age at diagnosis 7.7 years) were included in the study, with a median follow-up of 8.5 years. In univariate analysis, nailfold abnormality at baseline was the only risk factor that significantly correlated with the development of calcinosis (hazard ratio [HR], 4.86; p=0.03).

Multivariable analysis of factors including nailfold abnormality, age of diagnosis, sex, and duration from onset to diagnosis likewise revealed that only the presence of nailfold abnormalities significantly correlated with calcinosis development (HR, 4.98; p=0.03). In addition, calcinosis was markedly higher in patients with a chronic course (chi-square, 25.8; p<0.001).