Comparison of patients with juvenile psoriatic arthritis and nonpsoriatic juvenile idiopathic arthritis: how different are they?
OBJECTIVE
To compare the clinical features and outcome between patients with juvenile psoriatic arthritis (JPsA) and non-JPsA juvenile idiopathic arthritis (JIA).


METHODS
Fifty-three children with JPsA, 32 with < 5 joints in the first 6 months of disease (oligo-JPsA) and 21 (> or = 5 joints) polyarticular-onset (poly-JPsA) were compared to 53 patients with JIA who were matched by sex, age, date of diagnosis, and articular onset pattern.


RESULTS
There was no difference in the percentage of patients between the oligoarticular groups who developed extended oligoarthritis or in the percentage of patients who were positive for antinuclear antibodies. The only differences were that 25% of patients with oligo-JPsA had dactylitis compared to 0% of patients with oligo-JIA (p < 0.01) and 50% had nail pitting as compared to 18.7% (p < 0.05). In polyarticular patients the percentages with dactylitis were similar (19% vs 38%; p = 0.25). The frequency of uveitis was identical in the oligoarticular patients but a higher rate was seen in poly-JPsA compared to poly-JIA (23.8% vs 0%; p = 0.02), while contractures were more frequent in poly-JIA compared to poly-JPsA during the course of the illness (47.6% vs 14.3%; p = 0.03) but not at last followup (14.3% vs 4.7%; p = 0.6). At last followup the mean Childhood Health Assessment Questionnaire scores were similar in both the polyarticular and oligoarticular groups.


CONCLUSIONS
There were only a few differences between patients with JPsA and JIA regarding disease onset, disease course, and outcome. We suggest that large, longterm prospective studies are required to accurately determine whether subdividing JIA according to psoriasis is worthwhile.
Butbul
Yonatan Aviel
YA
Division of Rheumatology, Hospital for Sick Children, Toronto, Ontario, Canada.
Tyrrell
Pascal N
PN
Schneider
Rayfel
R
Dhillon
Sandeep
S
Feldman
Brian M
BM
Laxer
Ronald M
RM
Saurenmann
Rotraud K
RK
Spiegel
Lynn
L
Cameron
Bonnie
B
Tse
Shirley M
SM
Silverman
Earl D
ED
D000293:Adolescent; D000367:Age Factors; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001171:Arthritis, Juvenile / Q000145:classification* / Q000175:diagnosis* / Q000188:drug therapy; D015535:Arthritis, Psoriatic / Q000145:classification* / Q000175:diagnosis* / Q000188:drug therapy; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006306:Health Surveys; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D017063:Outcome Assessment, Health Care; D010641:Phenotype; D011379:Prognosis; D012737:Sex Factors
D000894:Anti-Inflammatory Agents, Non-Steroidal