[Effective cyclophosphamide pulse therapy for an young infant with severe dermatomyositis]

We herein report a 3 year-old boy, who showed proximal muscle weakness and pain at the age of one and a-half years. When he visited our hospital at the age of 1 year and 11 months, he could hardly move by himself. He also had difficulty in swallowing and suffered from multiple dermal ulcers. His blood test showed slightly elevated muscle enzyme activity, and magnetic resonance imaging suggested severe inflammation of the muscles. Radiological examination proved hypoperistalsis of the esophagus. With additional skin and muscle biopsies, we diagnosed him with juvenile dermatomyositis (JDM). Methyl-prednisolone pulse therapy was not effective enough, thus oral methotrexate, cyclosporine A and monthly cyclophosphamide pulse therapy were added. After the fourth cyclophosphamide pulse therapy, his muscular strength was restored, and the ulcers healed dramatically. Due to scarcity of severe cases, neither standardized classification nor grading system for severity in JDM has ever been established, which perplexes physicians in finding the best therapeutic strategy. Further investigation, experience and efforts are necessary to standardize an evaluating system and therapeutic strategy against JDM.