The spondyloarthropathies (SpA) are important inflammatory rheumatic diseases--not only because patients of young age are frequently involved. Ankylosing spondylitis, reactive arthritis, and undifferentiated spondyloarthropathy are prototypes of SpA which share several clinical features and the strong association with HLA B27. Despite its high prevalence there are many shortcomings in early diagnosis and therapy of SpA. The same is true for the knowledge on course, prognostic factors, and the socioeconomic consequences of these diseases. Furthermore, our knowledge about pathogenesis and therapy is still limited. Due to the known deficiencies in rheumatologic education, there are clear-cut deficiencies in the health care provided by general practitioners. The aim of the project presented here is to built up a cohort of early SpA patients to learn about course and outcome of SpA. In this regard, special attention is paid to the inclusion of patients with juvenile SpA since AS starts frequently in the 2nd decade of life and because the clinical picture with more frequent peripheral joint involvement differs from AS of adult onset. Moreover, these cohorts play an essential role for other projects of the MedNet subdivision of infect-associated arthritides/spondyloarthropathies in which studies on diagnosis, therapy, immunology, and genetics of the SpA performed.