Two Cases of Adverse Reactions of Hyaluronic Acid–based Filler Injections

Hyaluronic acid (HA) is one of the natural components of the human body with high biocompatibility, biodegradability, and nonimmunogenicity, which makes it the ideal biomedical filling agent currently available. However, for many medical practitioners, HA filler injections remain a relatively new item to carry out. Learning while practicing, it is inevitable to encounter some difficulties and adverse reactions in its application. Here we report two cases of adverse reactions to HA-based filler injections, including anaphylactic reaction on the face and vascular thrombosis after augmentation rhinoplasty with HA filler. In this report, we highlight the management and prevention of the adverse reactions, especially in case 2, because vascular thrombosis is one of the severe complications and injectors should know how to avoid it and how to deal with it, thereby increasing the safety of HA-based procedures.