Should we reconsider withholding iron replacement therapy in acute infection?

Intravenous iron is commonly withheld during acute infection due to concerns that iron availability may promote microbial growth and worsen outcomes. Yet, the supporting clinical evidence is less definitive than one might realise. Early clinical concern was derived largely from observational studies in haemodialysis populations where intravenous iron exposure, particularly at higher or bolus dosing, was associated with bacteraemia or infection-related hospitalisation. However, these studies were susceptible to confounding and not uniformly replicated. More recent evidence is mixed. A large meta-analysis found a modest increase in infection risk with intravenous iron but also showed improved haemoglobin and reduced transfusion requirements. Newer cohort studies in acutely infected patients suggest intravenous iron is not uniformly followed by deterioration and may, in selected groups, be associated with improved haemoglobin recovery and survival. We argue that blanket avoidance is overgeneralised. Intravenous iron has a role to play in acute infection in selected populations and future research will help inform a more nuanced approach.