Injected Hyaluronidase Reduces the Volume of Exogenous Hyaluronate Fillers in Mice and Results in Clinical Improvement in a Patient with Pretibial Myxedema

BACKGROUND Hyaluronidases are essential for the breakdown of hyaluronate (HA) in tissues and may be used to prevent the adverse effects of HA fillers. OBJECTIVES We explored the effect of hyaluronidase on exogenous and endogenous HA in vitro and in vivo. MATERIALS AND METHODS HA fillers were incubated with different concentrations of hyaluronidase and visualized by electrophoresis. HA fillers were injected in the skin of hairless mice, and 4 h later hyaluronidase was injected in the papules of exogenous HA. Hyaluronidase was injected in the nodule of pretibial myxedema of a male patient with Graves' disease. Skin sections of mice and of the patient were performed, and a skin ultrasound system was used to monitor the evolution of skin lesions. RESULTS Hyaluronidase showed a degrading effect on HA with increasing concentrations. Hyaluronidase injection significantly decreased the content of exogenous HA within 3 days. Intralesional injection of hyaluronidase resulted in dissolution of the nodule of pretibial myxedema with no recurrence during 3 months. CONCLUSION These results show that the injection of hyaluronidase is capable of degrading exogenous HA in mouse skin and endogenous HA in human skin in vivo and may be a therapeutic option for skin diseases characterized by abnormal accumulation of HA.