Bone Abstracts

Juvenile dermatomyositis (JDM) is a severe connective-tissue disease of unknown etiology characterized by inflammatory process affecting muscles and skin, with subsequent presentation in the joints, esophagus, lungs, and the cardiovascular system. Clinical presentation also includes deposition of calcium in the skin (calcinosis cutis) which is typically seen in the juvenile DM, contrary to the adult form. The pathogenesis of JDM-related calcinosis remains unclear whereas it is a complication developed by 30–70% of patients, and is a major cause of morbidity and impaired quality of life.

We present a case series of skin calcinosis in three patients (13-year-old boy, 13-year-old girl and a 6-year-old girl) diagnosed of JDM. The aim of this study was to depict clinical course of cutaneous calcifications, and to demonstrate the effects of treatment with cyclic intravenous pamidronate (PAM). The children met the standard diagnostic criteria for JDM and all were intensively treated with glucocorticoids, methotrexate and/or immunoglobulins for more than 2 years. Massive formations of calcium deposits in different locations of the skin and soft tissues were observed while in one of these patients, calcinosis was the first symptom predating the clinically apparent JDM. Some of the foci reached a large size, tumor-like shape and considerably limited joint mobility. Over the time of observation, the children received two to eight pamidronate series (3-day-long cyclic iv. PAM administration, 4-months intervals). A distinct alleviation and reduction of size of the deposits were observed during the treatment. No newly formed deposits were found whereas most of the foci disappeared, and physical function had improved; no severe adverse effects were reported except of mild transient hypocalcemia in one patient.

Conclusion: The PAM therapy is an effective and safe symptomatic management of the calcinosis in the course of JDM, although the cause-effect mechanism remains not fully clear. A question arises: What is the optimal treatment for calcinosis in the course of JDM, when the treatment should be implemented and for how long should it be continued? There is a need of further investigation regarding the optimal dose and maintenance therapy for disseminated skin calcinosis and/or combination with other drugs being possibly more effective.

Disclosure: The authors declared no competing interests.