[Reactive, infectious, or postinfectious arthritis?].

The issue of reactive arthritis belongs to one of the most complex problems in rheumatology. Although the original concept of reactive arthritis as a „sterile arthritis“ has already been overcome, much remains unclear. Non-uniform terminology, classification and diagnostic criteria as well as treatment guidelines leave room for different interpretations of this issue. Therefore it is difficult for non-rheumatologists (internal medicine physicians and general practitioners) to find their way around this topic. Our comprehensive report discusses the latest findings from etiology to treatment of reactive arthritis. It also addresses the aforementioned controversies from terminology to the latest list of causative pathogens, including viruses, parasites and vaccines.