Update on Post-Streptococcal Reactive Arthritis: Narrative Review of a Forgotten Disease.

PURPOSE OF THE REVIEW: This topical review attempts to build the concepts of PSRA as an independent entity and discuss prevalent diagnostic criteria. It utilizes a search strategy to collate all clinical features of PSRA reported from across the world and also discusses laboratory and treatment options in brief. RECENT FINDINGS: There are several immune-mediated diseases described after acute streptococcal infections. Post-streptococcal reactive arthritis (PSRA) is a sterile, self-limiting arthritis that occur as an immune sequelae to streptococcal infection. Though PSRA resembles the arthritis of acute rheumatic fever superficially, it is a separate entity in its own right. It is different from classical reactive arthritis too. It was being recognized worldwide and more frequently in the recent past, possibly due to heightened awareness amongst clinicians. However, research on this enigmatic immune phenomenon is limited. Most acceptable hypotheses suggest molecular mimicry sensitizing the immune system towards synovial peptides such as keratin, vimentin and laminin, leading to arthritis in a genetically predisposed individual. There is still much to be learnt from this unique disease about the vagaries of the immune system.