The aim of this study was to evaluate the clinical features, evolution and
reliability of spondyloarthropathy criteria in a subset of patients with su
bclinical sacroiliitis and inflammatory bowel disease (IBD). All patients w
ith IBD (n 62) attending a gastroenterology clinic from a referral centre w
ere included to assess the prevalence of articular involvement. Patients we
re evaluated according to a specific protocol designed for the study, which
included epidemiological and clinical variables, physical examination and
radiological assessment. Only those with subclinical sacroiliitis were foll
owed prospectively for 4 years. This group was visited every 6 months with
the same initial protocol. Sacroiliac joints were studied using frontal and
oblique X-ray views and graded according to New York criteria. HLA B27 typ
ing was performed by serological methods in all patients and in 80 healthy
controls. The reliability of Amor and ESSG criteria for spondyloarthropathy
was evaluated. Fifteen patients (24%) presented with isolated subclinical
sacroiliitis. In this group a higher frequency of peripheral arthritis and
erythema nodosum was observed (p = NS compared to those without sacroiliiti
s). Most cases (60%) were grade II unilateral sacroiliitis. Three patients
were HLA B27+ (p>0.05 compared to healthy controls). The resultant sensitiv
ity of Amor's and ESSG criteria ranged from 40% to 46%. An unexpectedly hig
h freuqency (9.5%) of psoriasis was observed in the whole group. There is a
high prevalence of isolated subclinical sacroiliitis in IBD. This may repr
esent a forme fruste of enteropathic ankylosing spondylitis, a stunted form
of axial involvement because of therapy, or a third category of rheumatic
disease associated with IBD. It may also represent a common characteristic
of spondyloarthropathies, rather than a specific finding of IBD. The recent
ly developed spondyloarthropathy criteria are not particularly helpful for
the diagnosis of this milder form of spondyloarthropathy.