Muscular Weakness with Calcinosis Cutis_A Case of Juvenile Dermatomyositis in a South Asian Male

Juvenile dermatomyositis (JDM) is an autoimmune connective tissue disorder characterized by an inflammation of proximal muscles of both upper and lower limbs in children below the age of 18 years. The condition mainly involves the proximal muscles and skin but extra-muscular involvement such as the gastrointestinal tract, lungs, and heart are also common.

We present a case of a 12-year-old south Asian male who developed weakness and muscular pain in all 4 extremities at 3 years of age. The condition gradually worsened recently, and the patient developed tender ulcerated skin nodules. Power in all 4 limbs was decreased and the patient was not able to perform his routine work such as combing of hair, closing a shirt button, and walking. Laboratory investigations revealed raised total leukocyte count (TLC) and erythrocyte sedimentation rate (ESR) and biopsy of the proximal muscles and skin lesions showed focal mild necrotic infiltrate involving nonnecrotic muscle fibers and calcinosis cutis respectively. A diagnosis of JDM was made and the patient was started on immunosuppressive therapy (steroids) and diltiazem.

JDM shares clinical features with other autoimmune, genetic, and inflammatory conditions. Proper history, thorough clinical examination, and laboratory workup is needed to rule out other masquerading conditions. This case report also highlighted the importance of diltiazem in the treatment of calcinosis cutis which is more commonly seen in patients with dermatomyositis.