Ankylosing spondylitis. Clinical features.

The clinical spectrum of ankylosing spondylitis (AS) is wider than just symptomatic sacroiliitis. The disease may be atypical or may occur as forme fruste. Atypical cases are encompassed in classification criteria for the whole family of spondyloarthropathies. AS may result primarily from additive genetic variability. Nonsteroidal anti-inflammatory drugs and physical exercise remain the cornerstone in the treatment of AS. Core sets for the assessment of the disease now exist for different treatment settings.