Long-term prognosis of patients with juvenile dermatomyositis initially treated with intravenous methylprednisolone pulse therapy.

OBJECTIVE: To assess the effects of initial treatment with intravenous methylprednisolone (IVMP) on the clinical course and laboratory measurements in patients with juvenile dermatomyositis (JDM), and to report the long-term prognosis of these patients.

METHODS: This was a retrospective study of 24 children with JDM, treated with IVMP as the initial therapy since 1981 and followed for a mean of 5.3 yrs. (range 10 months to 12.5 yrs.). Clinical and laboratory data, and complications of the disease and of therapy were ascertained by a chart review.

RESULTS: The disease in 13/24 patients initially treated with IVMP followed a monocyclic course. The mean time for patients with a monocyclic course to normalize skin and muscle strength parameters was shorter than for patients with a chronic course (p < 0.005). Patients with a chronic course received more IVMP (mean 12.3 doses) (p < 0.005), and took longer to achieve normal strength (14.9 mos.) (p < 0.005), and remission of skin rash (33.7 mos.) (p < 0.005). Patients with a chronic course suffered more disease- and treatment-related complications than patients with a monocyclic course.

CONCLUSION: Most patients whose disease followed a monocyclic course achieved normal muscle enzymes within one month and had improved muscle strength within 2.5 months of the initiation of therapy. If patients fail to achieve normal muscle strength over 4 months, muscle enzymes over 3 months and normalizing VWF over 10 months, there may be a higher probability that their disease will follow a chronic course.