Hyaluronic acid skin fillers: Adverse reactions and skin testing

Background: Hyaluronic acid (HA) fillers have been proposed as alternatives to other temporary skin fillers, such as bovine collagen, for treating fac ial skin lines and for providing lip augmentation. Several types of commerc ial HA fillers are now available in many countries, They include Restylane, which is produced by microbiologic engineering techniques, and Hylaform, w hich is HA extract derived from rooster combs. They have been approved for use in several countries, but not currently in the United States. There are no recommendations to perform pretreatment skin testing by the manufacture rs. Objective: Our purpose is to describe and comment oil our experiences with Hylaform and Restylane fillers. Observation of any side effects and skin te sting results were documented. Methods: Between September 1996 and September 2000, 709 patients were treat ed with Hylaform and Restylane and were followed up clinically for at least 1 year. Three of these patients (0.42%) developed delayed skin reactions. Three other patients were referred for evaluation of their skin reactions f rom other practitioners. Five of these 6 patients agreed to skin testing of their forearms. Results: In the 5 patients tested, challenge intradermal skin testing was p ositive in 4 patients; the reactions started approximately 8 weeks after in jection. Conclusions: There was a slight incidence of delayed inflammatory skin reac tions to two HA fillers. Both of these reactions occurred after the first a nd repeat injections. Challenge skin testing was positive in 4 of 5 tested patients.