High frequency of calcinosis in juvenile dermatomyositis: a risk factor study.

Objective: To assess the frequency of calcinosis in patients with juvenile dermatomyositis, and the possible risk factors for that manifestation. Methods: Medical record review of 34 patients, with an emphasis on the following characteristics: demographic, clinical and laboratory data; type of treatment; adherence to treatment; disease course (monocyclic, chronic and polycyclic); and disease severity. Patients were divided into two groups as follows: those who developed calcinosis (up to the sixth month of follow-up and after six months of follow-up) and those who did not develop calcinosis. Twenty-seven patients underwent two nailfold capillaroscopies (NFC), which were considered altered when the scleroderma pattern was found. Results: The mean age of symptom onset of the 34 patients was 6.5 years, the time until diagnosis was 1.2 years, and 70% were females. Half of the patients had a monocyclic disease course, and only 14.7% had severe vasculitis. Almost 90% of the patients undergoing NFC showed a change on the first assessment, 74% showed a change on the second assessment, and the mean interval between both assessments was 1.6 year. Calcinosis was evidenced in 16 (47.1%) patients. No association was observed between the variables analyzed and the development of calcinosis. Conclusion: No risk factors for calcinosis were identified in this study, although that complication was found in half of the patients with juvenile dermatomyositis studied.