Juvenile dermatomyositis at diagnosis: clinical characteristics of 79 children.
OBJECTIVE
To evaluate demographic and clinical characteristics, duration 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
Structured 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 (100%) and proximal muscle weakness (100%); 58 (73%) had muscle pain; 51 (65%) fever; 35 (44%) dysphagia; 34 (43%) hoarseness; 29 (37%) abdominal 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/nondiagnostic in 10 (20%). Median time from disease onset to diagnosis was different between racial groups: Caucasians (n=59) 2.0 months: for minorities (n=20), 6.5 months, (p=0.0008). The median time from disease onset to therapy was: Caucasians. 3.0 months; minorities, 7.2 months (p=0.002). Report of calcinosis was associated with increased time to diagnosis and therapy (p=0.04). In the 33 children whose first symptom occurred 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.


CONCLUSIONS
The results of an undirected site for muscle biopsy or EMG may not be diagnostic. Minority children had a longer interval between first JDM symptom and diagnosis/therapy than Caucasian children. Delay in diagnosis/therapy was associated with calcinosis.
Pachman
L M
LM
Division of Immunology, Children's Memorial Hospital/Northwestern University Medical School, Chicago, Illinois 60614, USA. pachman@nwu.edu
Hayford
J R
JR
Chung
A
A
Daugherty
C A
CA
Pallansch
M A
MA
Fink
C W
CW
Gewanter
H L
HL
Jerath
R
R
Lang
B A
BA
Sinacore
J
J
Szer
I S
IS
Dyer
A R
AR
Hochberg
M C
MC
D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003710:Demography; D003882:Dermatomyositis / Q000175:diagnosis* / Q000453:epidemiology*; D005006:Ethnicity; D005260:Female; D006297:Health Services Accessibility; D006801:Humans; D007223:Infant; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology; D012621:Seasons; D012923:Social Class; D013997:Time Factors; D014481:United States / Q000453:epidemiology