PRIMARY ANKYLOSING-SPONDYLITIS, PSORIATIC AND ENTEROPATHIC SPONDYLOARTHROPATHY - A CONTROLLED ANALYSIS

Within our ankylosing spondylitis (AS) population (n = 1331), 85% (n = 1128) had primary AS (1-degrees AS), 9% (n = 121) had psoriatic AS (PsAS) and 6% (n = 82) enteropathic AS (IBDAS). In an attempt to explore further the relationship between 1-degrees AS and the secondary spondyloarthritides, we evaluated 121 consecutive patients with PsAS and 82 with IBDAS, as well as 202 controls with primary disease. The patients were matched for sex and age at review PsAS:48.1 (SD 11.3) years vs 1-degrees AS:48.4 (SD 11.5), and IBDAS:46.0 (SD 12.7) vs 1-degrees AS:45.9 (SD 12.7). The sex distribution for IBDAS (M:F, 1:1), was significantly less (p < 0.001) than that for PsAS (M:F, 3.5:1) or 1-degrees AS (M:F, 2.4:1). Overall, compared to 1-degrees AS the PsAS and IBDAS tended to have greater disease severity as defined by e.g., (1) those taking nonsteroidal antiinflammatory drugs, 86 vs 72% (p < 0.01) and 71 vs 60% (p < 0.05), respectively; (2) decreased spinal mobility (scale 0-8) 5.0 (SD 2.0) vs 4.4 (SD 2.3); p = 0.029 and 4.9 (SD 2.0) vs 3.9 (SD 2.4); p = 0.024, respectively; and (3) PsAS resulted in a higher AIMS pain score; 4.9 (SD 2.5) vs 4.0 (SD 2.4): p = 0.042. By contrast, peripheral joint involvement, number of total hip replacements and capacity for employment were similar in all 3 groups. In conclusion (1) among the AS population the prevalence of 1-degrees AS, PsAS and IBDAS is 90, 6 and 4%, respectively. (2) The sex ratio of PsAS, 1-degrees AS and IBDAS is M:F-3.5:1. 2.4:1 and 1:1, respectively. (3) Overall, disease severity is in the order of PsAS > IBDAS > 1-degrees AS.