Delayed-Onset Nodules to Differentially Crosslinked Hyaluronic Acids: Comparative Incidence and Risk Assessment

Robust and long-term data on true incidence of delayed-onset nodules and immune tolerance of hyaluronic acid (HA) fillers are lacking.To characterize the incidence of delayed nodules in Vycross (VYC) HA fillers compared with previously reported FDA and non-FDA data of all HA fillers.The incidence of delayed nodules in all patients who had received VYC fillers in a 12-month period was assessed through a retrospective chart review. Nodule incidence for currently approved nonanimal-stabilized hyaluronic acid (NASHA) fillers was assessed using the FDA Summary of Safety and Effectiveness Data.Overall, 1,029 patients received 1,250 VYC filler treatments. Five patients developed delayed nodules to VOB, with an incidence of 1.0% per patient and 0.8% per syringe. No nodules were observed in patients who received VLR or VOL. All nodules were treated successfully using a combination of intralesional triamcinolone and hyaluronidase. Compared with other currently approved NASHA fillers, VOB is associated with a higher incidence of nodule formation.The introduction of VYC HAs has introduced a new variable that may be changing the immune tolerance of these substances, resulting in a higher incidence of delayed nodules than previously expected.