Allergic reaction to hyaluronidase use after hyaluronic acid filler injection.

Hyaluronic acid (HA) is biocompatible, easy to use and reversible. HA fillers are considered to be safe, although some complications can occur. At this time, hyaluronidase is used off-label for correction. A 41-year-old woman presented to our clinic for focal erythematous plaque on hyaluronidase injection site. She got the injection for correction of HA filler excess. The skin lesion continued for 7 days. Histopathologic findings were nonspecific. On intradermal skin test, allergic reaction to hyaluronidase were confirmed. Adverse effects of this hyaluronidase are uncommon with local injection site reactions most frequently reported. Allergy to hyaluronidase should be included in the differential diagnosis when focal erythema and swelling occur after hyaluronidase injection.