[Acute non-traumatic single-articular pain].

The main non-traumatic causes of acute single-joint pain are microcrystalline, degenerative, reactive and septic arthritis. Septic arthritis must be excluded quickly with puncture of the joint effusion. In the absence of sepsis, surgical drainage can be performed within 24 hours after admission to the emergency unit. Concerning gout, recommendations advise the use of imaging for diagnosis in case of joint puncture not feasible and the introduction of urate-lowering treatment during the acute attack. Regarding reactive arthritis, the presence of microbial elements in the affected joints improves the understanding of its pathophysiology. Finally, osteoarthritis guidelines emphasize the importance of self-management programs for painful crises.