A Brazilian registry of juvenile dermatomyositis: onset features and classification of 189 cases.
OBJECTIVE
To describe onset features, classification and treatment of juvenile dermatomyositis (JDM) and juvenile polymyositis (JPM) from a multicentre registry.


METHODS
Inclusion criteria were onset age lower than 18 years and a diagnosis of any idiopathic inflammatory myopathy (IIM) by attending physician. Bohan & Peter (1975) criteria categorisation was established by a scoring algorithm to define JDM and JPM based on clinical protocol data.


RESULTS
Of the 189 cases included, 178 were classified as JDM, 9 as JPM (19.8: 1) and 2 did not fit the criteria; 6.9% had features of chronic arthritis and connective tissue disease overlap. Diagnosis classification agreement occurred in 66.1%. Median onset age was 7 years, median follow-up duration was 3.6 years. Malignancy was described in 2 (1.1%) cases. Muscle weakness occurred in 95.8%; heliotrope rash 83.5%; Gottron plaques 83.1%; 92% had at least one abnormal muscle enzyme result. Muscle biopsy performed in 74.6% was abnormal in 91.5% and electromyogram performed in 39.2% resulted abnormal in 93.2%. Logistic regression analysis was done in 66 cases with all parameters assessed and only aldolase resulted significant, as independent variable for definite JDM (OR=5.4, 95%CI 1.2-24.4, p=0.03). Regarding treatment, 97.9% received steroids; 72% had in addition at least one: methotrexate (75.7%), hydroxychloroquine (64.7%), cyclosporine A (20.6%), IV immunoglobulin (20.6%), azathioprine (10.3%) or cyclophosphamide (9.6%). In this series 24.3% developed calcinosis and mortality rate was 4.2%.


CONCLUSIONS
Evaluation of predefined criteria set for a valid diagnosis indicated aldolase as the most important parameter associated with definite JDM category. In practice, prednisone-methotrexate combination was the most indicated treatment.
Faculdade de Medicina de Botucatu, UNESP, São Paulo, Brazil.
J O
JO
Sato
A M E
AM
Sallum
V P L
VP
Ferriani
R
R
Marini
S B
SB
Sacchetti
E M
EM
Okuda
J F
JF
Carvalho
R M R
RM
Pereira
C A
CA
Len
M T
MT
Terreri
S A
SA
Lotufo
P R
PR
Romanelli
V C S
VC
Ramos
M O
MO
Hilario
C A
CA
Silva
J E
JE
Corrente
C
C
Saad-Magalhães
D000293:Adolescent; D017668:Age of Onset; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D003882:Dermatomyositis / Q000145:classification* / Q000175:diagnosis* / Q000188:drug therapy; D018450:Disease Progression; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007223:Infant; D008297:Male; D018579:Patient Selection; D012042:Registries; D012044:Regression Analysis; D012720:Severity of Illness Index; D016896:Treatment Outcome
D005938:Glucocorticoids