Geoepidemiology: the environment and spondyloarthropathies

Spondyloarthropathies (SPA) are a group of common inflammatory rheumatic disorders characterized by axial and or peripheral arthritis, associated with enthesitis, dactylitis and potential extra-articular manifestations such as uveitis and skin rash. The diseases which comprise the group, share a common genetic predisposition, the HLA-B27 gene, however this association varies markedly among the various SPAs and among different ethnic groups. Environmental factors seem to be triggering the diseases in the genetically predisposed. The radiographic hallmark of the group is sacroiliitis, which when present is of help in the diagnosis. Various sets of diagnostic and classification criteria were developed over the years with the latest European Spondyloarthropathy Study Group (ESSG) criteria which are the most widely used. MRI changes have been included in the new classification criteria of early axial SPA and are now considered as a major tool in the diagnosis. Until recent years, there were no real disease modifying anti-rheumatic drugs which were able to halt the disease progression. Tumor necrosis factor (TNF)-alfa blocking agents, have now become the mainstream of therapy providing the patients an effective treatment option.