Severe acute localised reactions after intra-articular hyaluronic acid injections; a narrative review and physician’s guide to incidence, prevention, and management of these adverse reactions.

Hyaluronic acid (HA) also known as hyaluronan, and its associated derivatives have been used as part of the management of osteoarthritis, particularly osteoarthritis of the knee, for over 3 decades.¹ Adverse reactions relating to the injection of HA into joints have been reported as being as low as 3.7% and as high as 8.5%. Notably in placebo-controlled trials the rates of adverse events from HA injection are the same as that of the placebo group.¹ Perhaps the most common adverse event a physician is likely to encounter is pain and swelling of the joint, which varies in severity from mild pain requiring little more than expectant recovery to more severe reactions, termed severe acute localized reactions (SALR) or pseudo-sepsis.

This paper provides the injecting physician with a review of the incidence and postulated causes of SALR, insights into the prevention of these adverse events and a discussion of the management of these events. Figure shows the flowchart of the prevention and management of the SALR after intra-articular HA injection.