Juvenile and adult dermatomyositis among the Chinese: a comparative study.

Between 1983 and 1992, 11 children and 38 adults were seen at Taichung Veterans General Hospital with a definite diagnosis of dermatomyositis. Their clinical pictures, laboratory findings, courses and outcomes were compared. The mean age at diagnosis was 12 years and 50 years, respectively. Children had a higher female-to-male ratio (2.7:1 vs. 1.2:1) and a more acute onset, while adults had a higher incidence of malignancy and other connective tissue disease associations. Clinically, shawl sign was more common in the adults, whereas myalgia was more frequently seen in the children (0.05 < p < 0.1). Hemograms, serological parameters and immunological investigations showed no significant differences between the two groups. Elevated erythrocyte sedimentation rate and circulating immune complexes were found in over half of both groups of patients; however, their values bore no relationship to either disease activity or future outcome. Although no significant differences were demonstrated between the two groups of patients with regard to either clinical manifestations or laboratory findings, the disease entity seemed not to be the same because evidence of vasculopathy in muscle pathology was more prominent in the children, with endothelial swelling and necrosis the most common findings. Steroids had been used as the first choice of therapy in both groups of patients, followed by cytotoxic drugs and immunosuppressants. Children had a more favorable outcome compared to a 24% mortality rate in the adult group. Experience here recommends a complete cancer work-up in adults, especially for nasopharyngeal carcinoma among the Chinese. Various autoantibodies screenings may also be helpful for early detection of other associated connective tissue diseases.