Consensus Guidance on Hyaluronidase: Why It Still Matters

In 2018 a group of UK aesthetic clinicians published consensus guidance on hyaluronidase, the enzyme used to dissolve hyaluronic acid filler. Newer protocols have refined some details since then, but the core principles it set out still matter to patients: filler clinics should be ready to use this enzyme, emergencies call for prompt and generous treatment, and routine dissolving should be planned with care.

Why this was studied

Hyaluronidase is a naturally occurring type of enzyme that breaks down hyaluronic acid. In aesthetic medicine it is used to soften or remove hyaluronic acid filler, either because a result is not what the patient wanted or, more urgently, because filler is blocking a blood vessel.

Before this guidance, practice varied a great deal. Doses, dilution, allergy testing and follow-up differed from clinic to clinic, and much of its aesthetic use is outside its original licensed purpose. The authors, working with an expert complications group, aimed to bring the available evidence and expert opinion together in one practical document.

What the researchers did

This is a consensus guideline, not a trial. An expert panel reviewed the published literature and their collective experience, and a wider consensus group agreed on recommendations. The document did not describe a formal grading system for the strength of each recommendation, which is common for guidance in fields where large trials are scarce.

What the guidance recommended

Without walking through every detail, the key principles were:

• Vascular occlusion is an emergency. If filler is suspected of blocking a vessel, treatment with hyaluronidase should start immediately, using a high-dose, repeated approach over the whole affected area, with reassessment of blood flow and close follow-up over the next days.
• Vision changes need hospital care. Any sudden change in vision after filler should be treated as an emergency with urgent transfer to an eye department. The guidance noted that the window to restore blood flow to the retina is very short.
• Non-urgent dissolving is titrated. For overcorrection, misplacement, a bluish tint under thin skin, or lumps from hyaluronic acid, smaller amounts are used and the result is assessed after about two days before more is given.
• Allergy is possible but uncommon. The guidance cited local reactions in well under 1% of cases and more serious allergic reactions as rarer still. It recommended a skin test before non-urgent use, but said testing should be skipped in an emergency where delay could cause harm.
• Inflamed lumps need assessment first. If a delayed lump looks infected or inflamed, antibiotics or other treatment may be needed before or alongside dissolving.
• Medical history matters. A history of bee or wasp sting allergy was listed as a reason for extra caution, and some medications can interact with the enzyme or reduce its effect.

How strong is this evidence?

Consensus guidance is built from expert agreement and whatever studies are available, which in this area are mostly case reports, case series, animal studies and laboratory work. It is valuable when trials are not available, but individual recommendations, especially exact doses, may change as better evidence emerges.

Since 2018, other groups have published updated protocols, and practice has continued to evolve, for example in the use of ultrasound to guide where the enzyme is placed. So the specific numbers in this document should not be treated as the final word. The broader principles, however, remain widely shared.

What it means for you

The most practical point is that any clinic offering hyaluronic acid filler should keep hyaluronidase on hand and have staff trained to use it quickly. It is reasonable to ask about this before your first treatment. Our article on vascular occlusion safety describes the warning signs and why preparation matters.

Know the signs that need same-day attention after filler: increasing or severe pain, skin that turns pale, dusky, blotchy or purple, coolness of the skin, or any change in vision, headache with visual symptoms, or difficulty moving the eye. Vision changes need emergency care immediately.

If you simply do not like a result, dissolving is usually a planned, non-urgent procedure. It can take more than one session, the area may look a little deflated or uneven at first, and some swelling and bruising are common. Our article on dissolving filler explains what to expect.

Hyaluronidase only works on hyaluronic acid. It does not dissolve collagen-stimulating products such as calcium hydroxylapatite or poly-L-lactic acid (PLLA), which is one reason to know exactly what product was used in a previous treatment.

People with known allergy to the enzyme should not receive it, and those with insect sting allergies, active infection at the site or who are pregnant need individual discussion. Do not stop any prescribed medicine before a procedure without talking to your prescribing doctor.

Questions to ask at your consultation

• Do you keep hyaluronidase in the clinic, and who is trained to use it?
• What is your plan if a blood vessel is affected during or after treatment?
• Will I need a skin test before planned dissolving?
• How many sessions might it take to dissolve my previous filler?

Frequently asked questions

Does hyaluronidase dissolve my own natural hyaluronic acid?

It can act on the body's own hyaluronic acid in the area, but the body replaces this naturally over a short time. Temporary softening or a slightly hollow look can occur and usually settles.

Why is a skin test sometimes skipped?

In an emergency such as a blocked vessel, waiting for a test result could allow tissue damage. The guidance advised that the benefit of prompt treatment outweighs the small allergy risk in that situation.

How quickly does it work?

Softening often starts within minutes to hours, though denser fillers may take a day or two. The final result is usually assessed after a couple of days.

If you have questions about previous filler or about how complications are handled, HealthPark Medical Aesthetics is happy to explain its safety protocols during a consultation.

Source

King M, Convery C, Davies E. The use of hyaluronidase in aesthetic practice (v2.4). Journal of Clinical and Aesthetic Dermatology, 2018. Read the study