Hyaluronic acid is the most common filler used in the United States for cosmetic procedures. . However, there has been little research and there are no formal clinical guidelines on its use. Hyaluronidase is approved by the Food and Drug Administration for several indications, but its use in cosmetic procedures is off-label.
Hyaluronic acid filler complications can be local and transient or delayed and/or dangerous. Local reactions generally improve over time or respond to symptomatic care. But granulomatous reactions, misplaced injection, adverse aesthetic outcomes, and vascular occlusion are some of the detrimental outcomes that require immediate treatment, often using hyaluronidase, a naturally occurring enzyme that degrades hyaluronic acid.
Dr. Lily Talakoub
Hyaluronic acid products vary in concentration, cross-linking, type of cross-linker used, and particle size, and therefore display different degradation patterns with hyaluronidase. The three hyaluronidase products available also vary in concentration, source, and enzyme activity. Hyaluronidase has a half-life of 2 minutes but has a duration of action of 24-48 hours depending on the product used.
In an interesting study by Casabona G et al., the dose and activity of five hyaluronidase products available worldwide were used to degrade five different fillers (Juvederm Volbella, Voluma, and Ultraplus; Belotero, and Belotero Balance) with various concentrations and cross-linking in human skin. The results showed that the Vycross products (Juvederm Voluma) are the least sensitive to hyaluronidase and require the greatest concentration of hyaluronidase and a longer time for dissolution requiring up to three times more hyaluronidase to degrade the same volume of other hyaluronic acid products.
In addition, the ovine hyaluronidase product marketed in the United States as Vitrase had the greatest activity against the range of hyaluronic acids used in the trial. Higher concentrations of hyaluronidase also could produce type-I hypersensitivity reactions and angioedema in susceptible patients as evidenced by eosinophilic tissue reactions at concentrations greater than 300 IU.
Hyaluronidase is stored at cool temperatures (35-46° F). It can be reconstituted with saline, water, or bacteriostatic saline for reducing injection site pain; however, it should not be mixed with local anesthetic. The volume of diluent used depends on the surface area treated and ranges from 1 mL to 10 mL. Smaller volumes are used for more concentrated local injection and larger volumes for more precise dosing.
For impending necrosis, hyaluronidase should be used within minutes to hours of blanching of the skin and the area should be flooded every 30 minutes until the tissue has reperfused. Depending on the type of filler used, the volume of injection varies and the area should continually be injected and tissue response observed. A high-dosed large-volume protocol allows the tissue perfusion to gradually infiltrate the vessel walls. Recommendations are 2 mL of bacteriostatic saline diluted with a vial of hyaluronidase. Retrobulbar injection of hyaluronidase within minutes of retinal artery occlusion in doses of 150-200 units in 2-4 mL of diluent into the inferolateral orbit by an experienced ophthalmologist or oculoplastic surgeon is recommended.
Although there is no consensus, there are various clinical studies using hyaluronidase dilutions varying between 5 and 30 units to break down 0.1mg/mL of hyaluronic acid for the reversal of facial hyaluronic acid fillers. In my clinical experience, the recommendation is that, apart from necrosis, the concentration used is titrated to clinical efficacy, which can also be done over multiple appointments every 48 hours until the desired outcome is achieved.
Complications from hyaluronidase injection include local tissue erythema, edema, pain, allergic reactions, and anaphylaxis. An intradermal patch test of 10-20 units of hyaluronidase in the forearm can be done in patients with a history of allergy to hyaluronidase, which, in people with sensitivity, results in a wheal within 30 minutes of injection. If a patient has a positive patch test, hyaluronidase cannot be used. In addition, a history of allergic reactions to bees may pose a heightened reaction to hyaluronidase and is a contraindication to use.
It is recommended that any practitioner using hyaluronic acid fillers keep 2-3 vials of hyaluronidase available at all times in the event of a vascular emergency. Stability, storage, and expiration dates should also be monitored closely.
Dr. Talakoub and Naissan O. Wesley, MD, are cocontributors to this column. Dr. Talakoub is in private practice in McLean, Va. Dr. Wesley practices dermatology in Beverly Hills, Calif. Write to them at dermnews@mdedge.com. Dr. Talakoub has no relevant disclosures.
References
Casabona G et al. Dermatol Surg. 2018 Nov;44 Suppl 1:S42-S50.
DeLorenzi C. Aesthet Surg J. 2017 Jul 1;37(7):814-25.
Juhász MLW et al. Dermatol Surg. 2017 Jun;43(6):841-7.
King M. J Clin Aesthet Dermatol. 2016 Nov; 9(11):E6–8.
Kim M et al. J Clin Aesthet Dermatol. 2018 Jun;11(6):E61-8.