Higher prevalence of extra-articular manifestations in ankylosing spondylitis with peripheral arthritis.

OBJECTIVE: To study the difference in the clinical presentation of patients of ankylosing spondylitis (AS) with and without peripheral arthritis.

METHOD: We performed a retrospective analysis of case records of 271 AS patients seen in the last 15 years at our center and diagnosed as AS according to modified New York criteria. We compared clinical features between patients with and without peripheral arthritis.

RESULTS: There were 253 (93%) men with a M:F ratio of 9:1, and 78 (28%) patients had Juvenile onset AS (JAS). Mean age at the disease onset was 22.4 +/- 9.3 years. Eighty-four patients had peripheral arthritis. Patients with peripheral arthritis had significantly higher prevalence of onset in childhood (36% vs. 25% P = 0.04), hip joint involvement (55% vs. 44%, P = 0.04), dactylitis (10% vs. 1%, P = 0.0006), enthesitis (28% vs. 7%, P = 0.0006), and uveitis (36 vs. 20%, P = 0.005) when compared with patients without peripheral arthritis.

CONCLUSION: Higher prevalence of juvenile onset and extra-articular manifestations in the form of uveitis, dactylitis, and enthesitis in patients with peripheral arthritis suggests that this subset of AS might have different factors involved in disease pathogenesis.