Chemotherapy induced juvenile dermatomyositis: a novel presentation- a case report

Idiopathic connective tissue disease juvenile dermatomyositis (JDM) is characterised by inflammatory myositis and distinctive skin abnormalities. Only a few cases of Dermatomyositis (DM) owing to chemotherapy used to treat cancer have been reported, despite the fact that the link between DM and cancer in adults is widely known. We describe the case of a female, age 14, who experienced DM as a side effect of chemotherapy following enucleation for retinoblastoma. We also discussed our patient's likely pathophysiology of JDM after treatment.

A 14-year-old female came to our facility complaining of trouble walking and bluish-black discoloration on her neck, elbows, forehead, and knees that had been present for eight months. The patient had undergone enucleation of the left eye due to retinoblastoma, followed by 40 cycles of radiation therapy and 13 cycles of chemotherapy with Cyclophosphamide, Etoposide, Carboplatin, Vincristine, and Dactinomycin. Her serum LDH and CPK levels were high, and she tested positive for ANA. The muscle biopsy was consistent with the changes of DM. When electromyography was performed, it revealed tiny, fibrillating, polyphasic motor unit potentials and sharp, positive waves that were suggestive with DM. A diagnosis of JDM was made after taking into account the symptoms, biochemical data, muscle biopsy, and electromyography results. The patient's symptoms started to get better once methotrexate and oral corticosteroids were started.

This case report emphasises the value of ongoing observation after cancer chemotherapy because specific cutaneous and muscle symptoms may lead paediatricians to consider the possibility of chemotherapy-induced JDM, which is uncommon in young patients.