JUVENILE DERMATOMYOSITIS AT DIAGNOSIS - CLINICAL CHARACTERISTICS OF 79 CHILDREN

Objective. To evaluate demographic and clinical characteristics, durat ion of time between disease onset (date of first rash and/or weakness) , and diagnosis/therapy, as well as socioeconomic status, of children with newly diagnosed juvenile dermatomyositis (JDM). Methods. Structur ed telephone interview of families of a cohort of 79 children with JDM : interval between onset of symptoms to diagnosis, median of 3 months (range 0.5-20.0). Results. At diagnosis, all the children had rash (10 0%) and proximal muscle weakness (100%); 58 (73%) had muscle pain; 51 (65%) fever; 35 (44%) dysphagia; 34 (43%) hoarseness; 29 (37%) abdomin al pain; 28 (35%) arthritis; 18 (23%) calcinosis, and 10 (13%) melena, Muscle derived enzymes were normal in 10% of the children. Of the 43 children who had an electromyogram (EMG), 8 (19%) had normal results. Fifty-one children had a muscle biopsy; the results were normal/nondia gnostic in 10 (20%). Median time from disease onset to diagnosis was d ifferent between racial groups: Caucasians (n=59) 2.0 months; for mino rities (n=20), 6.5 months, (p=0.0008). The median time from disease on set to therapy was: Caucasians, 3.0 months; minorities, 7.2 months (p= 0.002). Report of calcinosis was associated with increased time to dia gnosis and therapy (p=0.04). In the 33 children whose first symptom oc curred in June-September, rash preceded or accompanied onset of muscle weakness in 83% (n=27). Ninety-one percent of the children were given steroid therapy and 9% received methotrexate as well. Conclusion. The results of an undirected site for muscle biopsy or EMG may not be dia gnostic. Minority children had a longer interval between first JDM sym ptom and diagnosis/therapy than Caucasian children. Delay in diagnosis /therapy was associated with calcinosis.