Juvenile dermatomyositis (JDM) is an inflammatory disease of the muscle, skin and blood vessels with peak age of onset 5-14 years and female:male ratio 1.7:1 [1,2]. Calcinosis is a hallmark sequelae [3]. Pamidronate has been used earlier for this indication [4] but there is lack of reported experience in Indian set-up.

A 9-year-old boy presented to us with complaints of fever, pain in all limbs and difficulty in walking for one and half months. Child was initially treated with non-steroidal anti-inflammatory agents (NSAIDS) after which pain had initially subsided to recur again. On examination, there was peripheral myopathy, heliotrope rash and Gottron papules. Laboratory investigations showed hemoglobin 7.7 g/dL, elevated lactate dehydrogenase (399 U/L) and creatinine phosphokinase (321 ug/L), and normal electromyogram. A muscle biopsy from Vastus lateralis showed features of immune-mediated inflammatory myopathy. Child was diagnosed as having JDM, and was started on steroids (20 mg/day), hydroxychloroquine (100 mg/day) and methotrexate (7.5 mg once a week). The child improved over the next 3 years with good compliance and regular follow-up, and gradually steroids were tapered to 5 mg/day. He presented after fall from a bicycle with swelling of the little finger with chalky white discharge for 3 days (Fig. 1a). X-ray revealed calcium deposits in soft tissue of little finger (Fig. 1b). Pamidronate was infused at 1 mg/kg/day for 3 consecutive days every 3 months. On follow-up after one year, there was complete clearance of calcinosis of fingers without any new focus and good disease control without signs of myositis (Fig. 1c and d).

Fig. 1 (a) Calcinosis in the little finger before treatment; (b) X-ray hand showing calcinosis before treatment; (c) clinical resolution of calcinosis after pamidronate; and (d) radiological resolution after pamidronate

An 11-year-old girl presented with complaints of swelling over right elbow and bilateral buttocks. She was diagnosed as having JDM at 8 years of age. She was initially treated with steroids, hydroxychloroquine and NSAIDS but had poor compliance to medicines. Following a fall from the stairs, she started developing calcinosis of buttocks followed by calcinosis of right elbow. There was presence of heliotrope rash and Gower sign. X-ray showed calcium deposits on affected areas. Child was started on 3-monthly pamidronate infusion after which there was significant decrease in calcinosis with no fresh foci. Complete resolution of disease process was not observed (Web Fig. 1a), but the compliance to drugs was also not optimal.

A 7-year-old girl presented with complaints of multiple swellings over the body and difficulty in walking for one year. The first swelling appeared in the waist region, followed by swellings in bilateral chest walls and scalp (Web Fig. 2 a). The swelling on the chest was excised by a local physician mistaking it to be an abscess. Following this, the child developed more swellings in the lateral chest near the site of excision (Web Fig. 2 b). On examination, there were nodules on left anterior chest wall with scar marks in bilateral infra-axillary area, Gottron papules and proximal myopathy. Laboratory investigations showed anemia with raised LDH and CPK. Hip X-Ray showed white nodular opacity around hip joint, suggestive of calcinosis (Web Fig. 2 c and d). Electromyogram showed membrane instability and fiber destruction. Child was diagnosed as a case of JDM with calcinosis and was started on steroids, hydro-xychloroquine, methotrexate, folic acid and 3-monthly pamidronate infusion. Follow-up after 1 year showed significant decrease in scalp swelling with complete disappearance of swelling over chest wall and the waist region with no new calcinosis.

Calcinosis is a hallmark sequelae of JDM [1]. Alum, alendronate, diltiazem and rituximab are few drugs used for treatment of calcinosis [3]. Pamidronate is a nitrogen-containing bisphosphonate which inhibits bone resorption used to treat osteoporosis [4]. Although the mechanism of action of pamidronate is unclear, it was chosen based on available adult studies [1,4,6]. A significant decrease in calcinosis was found in two cases whereas there was complete clearance in one case. Aggressive treatment with disease modifying anti-inflammatory agents (DMARDs) early in the course of disease seem to be effective in good disease control as was evident from case 1 and 3. Prompt diagnosis and early intervention prevents further calcinosis. Our results suggest that treatment with pamidronate infusion may achieve good disease control in prevention of further calcinosis in JDM.

Acknowledgments: Prof. MR Nayak, Honorable President, Siksha’O’ Anusandhan (Deemed to be) University and Mr Somadatta Das, Central Research Laboratory, IMS & SUM Hospital for technical support in submitting the manuscript.

Contributors: SG: collected data and drafted the manuscript; JRP, MD and MP: diagnosed the case, and planned the management. All authors approved the final version of manuscript.

Funding: None; Competing interest: None stated.

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