AB0122 Prevalence of spondylarthropathy and prediction of ankylosing spondylitis in patients presenting with inflamatory back pain
Authors: B Heidari
Journal: Annals of the Rheumatic Diseases (2001)

<h3>Background</h3> Back pain is a common symptom. It is one the first manifestations of ankylosing spondylitis (AS), which is also included in many sets of diagnostic criteria for spondylarthropathies (SPA). Definitive diagnosis of AS requires the presence of radiologic sacroiliitis, but its appearance lasts many years, so isolation of AS related back pain among patients with inflammatory back pain (IBP) is difficult and needs complete clinical examination with regard to specific signs and symptoms of AS. <h3>Objectives</h3> The objective of this study is to assess the prevalence of SPA and AS in patients with IBP and to predict the diagnosis of AS on the basis of clinical findings. <h3>Methods</h3> The study patients were seen in Shaheed Beheshti hospital clinic since 1994–1998. All patients presented with IBP which was confirmed clinically according to the criteria proposed by Clain <i>et al</i>. Patients assessment included, taking history, complete clinical examination for clinical sacroiliitis, buttock pain, arthritis, enthesitis, spinal mobility and chest expansion. Limitation of spine mobility and chest expansion was measured by standard tests. Pelvic radiograph was performed for all patients and appropriate diagnostic tests were requested as needed. Diagnosis of SPA and AS was confirmed by European Spondylarthropathy study Group (ESSG) criteria and the modified New York criteria respectively. Patients with history of spinal trauma, surgery, infectious, degenerative and neoplastic diseases of the spine were excluded from the study. <h3>Results</h3> Variables analysed for association of IBP with AS, reduction of chest expansion and limitation of the lumbar spin During the study period. 103 patients (52 males, 51 females) entered the study. the mean age of onset of IBP was 29 ± 7 (range 12–54) years, and the mean of the disease duration was 6 ± 5 (range, 0,5–20) years. Clinical examination revealed, arthritis in 20%, clinical sacroiliitis 35%, buttock pain 32%, enthesitis 58%, limitation of motion of the lumbar spine 54%, limited chest expansion 53%, radiographic sacroiliitis 60%, and HLA- B27 positive in 18 of 27(67%). 83% of patients met the ESSG criteria for SPA and 58% met the modified New York criteria for definite AS. Limitation of motion of lumbar spine and reduced chest expansion observed in 54% and 53% of patients respectively. 14 of 18 patients with AS carried HLA – B27(78%). Among the many e motions were the best predictors of the diagnosis of AS, by odds ratio of 3 and 4 respectively. <h3>Conclusion</h3> The results of the present study show that, the majority of IBP beginning at the third or forth decades of the life are due to SPA, and limitation of motions of spine and reduced chest wall expansion heralds the occurrence of AS. <h3>References</h3> van der Linden S, van der HeijdeDM. Ankylosing spondylitis and other B27 related spondylarthropathies. Balliers Clin Rheumatol. 1995;9:355–71 Clain A, Fries JF. Clinical history as a screening test for ankylosing spondylitis. JAMA 1977;237:2613–14 Clain A. Spondylarthropathy, undifferentiated spondylarthritis and overlap. In: Madison PJ, <i>et al</i>., eds. <i>Oxford textbook of rheumatology.</i> Oxford University Press, 1998: 1037–48