Suspected systemic rheumatic diseases in adults presenting with fever

A significant proportion of patients with pyrexia of unknown origin (PUO) are found to have a rheumatological cause. The mainstay of treatment for rheumatic disease is immunosuppression, and therefore, accurate diagnosis is crucial given the risks associated with these drugs. In this review, we analyse the rheumatological conditions that most commonly present with fever and illustrate clinical cases demonstrating some of the challenges in the workup of these patients. With this in mind, we propose an evidence-based algorithm for investigating PUO from a rheumatological perspective, with the aim that it will aid clinicians when approaching these clinical scenarios.