Correcting hyaluronic acid filler: preparing for a hyaluronidase session

Hyaluronidase is an enzyme that breaks down hyaluronic acid. It is what makes hyaluronic acid injections reversible: injected where the gel was placed, it dissolves it, whether it was injected at the practice or elsewhere. It is most often used by appointment, to correct a result; more rarely, as an emergency.

By appointment, or as an emergency

Most often for a result that does not suit you: an excess, an asymmetry, a small nodule that can be felt under the skin, product that has migrated beyond the treated area. The lips and under-eye hollows are the areas most concerned: gel placed too superficially can give them a puffy or bluish look. Whether the injection was done here or elsewhere, the approach is the same.

More rarely, as an emergency. If, in the hours or days after an injection, intense pain appears, or the skin turns pale, mottled, purplish or greyish, call the practice immediately, wherever the injection was performed — or go to the emergency department if no one answers. These signs may mean the product is obstructing blood flow in a vessel: hyaluronidase must then be injected without waiting until the next day. Any visual disturbance or eye pain means going to the emergency department without the slightest delay.

Preparing: what to bring

The name of the product injected, the date of the injection and, if you know it, where it was done. If you were given a card or label with the product’s name and batch number, bring it. Photographs from before the injection also help to gauge what needs correcting.

This is not a formality: hyaluronidase only dissolves hyaluronic acid. A product of a different kind — some so-called permanent fillers, in particular — does not respond to it, and the approach is no longer the same. If the injection was done at the practice, all of this is already in your file.

For a planned session, the rules of any injection apply: no aspirin, anti-inflammatories or omega-3 for the three days before, unless prescribed — a prescribed treatment is never stopped on your own. In an emergency, none of this should delay your coming in.

What to tell us

An allergy to bee or wasp stings — their venom contains an enzyme of the same family —, a reaction to a previous hyaluronidase session, an infection or a herpes flare-up on the area, pregnancy or breastfeeding.

Also mention all your treatments: some, such as cortisone, antihistamines or high-dose aspirin, can alter the enzyme’s effect or skew the allergy test.

How the session goes

For a planned session, an allergy test may be done first: a very small amount is injected into the skin of the forearm, and the reaction is observed for around twenty minutes. In an emergency, this test is not done — the benefit of the enzyme then outweighs the risk.

The enzyme is then injected where the product sits, in small amounts, with gradual dosing: a second session is better than an area that ends up hollow. The quantities are recorded in your file, as for any injection.

Afterwards, and what to do

The effect begins within hours and is judged at 24 to 48 hours. Swelling, redness and sometimes local itching are common on the first day, and settle on their own. No hammam, sauna or intense exercise for 24 hours.

Once the product has dissolved, the area returns to how it looked before the injection — including the hollow or thinness that prompted it. If a new injection is being considered, we usually wait two weeks for the skin to settle; it is decided in consultation, in front of your face.

When to call us back

Call without delay if the swelling spreads beyond the area, if itchy patches appear elsewhere on the body, or if breathing or swallowing becomes difficult: these are signs of allergy, and difficulty breathing calls for the emergency department. Call too in case of warm redness, increasing pain or fever.

After a session carried out as an emergency, follow-up is close: if the pain returns, or the skin does not regain its normal colour, call again immediately — a second injection may be needed.

None of the above replaces the prior consultation: it alone says whether this procedure is right for you, and on what terms.