Complications of injectable hyaluronic acid as a soft-tissue filler: a current overview

Hyaluronic acid filler is an injectable product for soft-tissue augmentation that proposes an improvement of facial aesthetics and, therefore, rejuvenation; it became popular for its favorable aesthetic outcomes, great biocompatibility and possibility of reversion. However, with the increasing number of procedures each day and more injectors, not always qualified, being licensed to perform them, the quantity of adverse events related to this filler material has intensified. In view of that, this article aims to make a research in the current literature about the most frequent complications of injectable hyaluronic acid fillers. An intense bibliographic search was accomplished using the keywords related linked to the subject on electronic scientific databases. Publications from 2015 to 2020 in English, Portuguese and Spanish language were selected, totalizing 46 articles consisting in case reports, reviews and clinical researches. The main adversities referred in the studies were immune responses, formation of nodules, infections, and vascular complications resulting in visual loss and necrosis. Professional injectors must be enlightened about such complications, being able to identify, prevent and successfully remediate them, mastering not only the injection techniques, but also the human anatomy and physiology, the properties of the chosen material and its correct indications to suit each patient.