Treating acne scarring with fillers

By Dr Renée Hoenderkamp / 01 Jul 2015

Dr Renée Hoenderkamp discusses the treatment of acne scarring with dermal fillers


Acne scarring can be distressing and stigmatising, especially when affecting the face. Whilst there are a multitude of treatment options available, I do see patients who have tried everything including combinations of lasers, peels, retinoids and needling, but are still searching for a solution. I therefore decided to try and treat some atrophic scars with hyaluronic acid (HA) fillers and witnessed some excellent results. When treating acne scarring with fillers, I use one of two techniques depending on the scar type and number. Injecting filler carefully into the dermis/epidermis underneath atrophic scars lifts them and improves the overall look of skin blighted by acne scarring. This can be done by either individually targeting pitted scars with a plumping filler or approaching an entire area with a lighter filler, used mainly as a skin booster for hydration and skin conditioning. Having said this, all filler types are being used to treat acne scarring.1

Anatomy of acne scarring

Acne scars occur when pustules go on to form nodules and cysts. Scarring is the result of skin damage during the healing of active acne. This process produces two typical scar types; atrophic and hypertrophic scars, depending on whether there is a net gain or loss of collagen in the healing process.2 A net loss forms an atrophic scar (80-90%) and a net gain a hypertrophic or keloid scar (10-20%).2 Both processes arise from the same pathophysiology, involving a transition through three stages of damage and healing. The damage caused initially by inflammation of a blocked sebaceous gland causes blanching and vasoconstriction. The immune response floods the area with granulocytes, macrophages, neutrophils, lymphocytes, fibroblasts, and platelets, preparing for granulation via immune mediator release. As granulation progresses the final stage is seen: matrix remodelling. The area is then flooded with enzymes, released from fibroblasts and keratinocytes, which determine the final structure of the extracellular matrix (ECM). Any imbalance in the enzymatic breakdown and rebuild of tissue results in scarring.2 When using fillers to treat acne scarring, only atrophic scars can be treated, because they are the only scars which are depressed, and these are generally classified into three types; boxcar, ice-pick and rolling (Figure 1): 

Figure 1: Acne scar subtypes

Pros and cons

Procedurally, the biggest consultation discussion point is permanence. Using semi-permanent fillers means improvement will gradually wear off and need repeating. My experience is that scars rarely return to their previous state due to a degree of subscision that occurs (and can be actively carried out) during administration. Filler type will dictate longevity, but I use HA fillers, so six to 12 months is the norm.3 Results are instant and improve over the following weeks. I often address specific scars for patients preparing for a big event, so timing is key and having the treatment a few weeks before the event, and not a few days, is always advisable. The procedure is painful but bearable. Some practitioners use lidocaine cream, but I find the associated local oedema is detrimental to scar visualisation, so I avoid using anaesthesia. Anecdotally, it appears to be less painful than lip fillers and these patients have often had many painful procedures to treat the indication previously, so may be more tolerant than other filler patients. Injection site redness and bruising is a possibility, as with all filler procedures, so careful consenting is key to managing expectations and guiding patients on how long potential side effects may last.

Is it effective?

Certainly my experience suggests the use of fillers is an effective solution for atrophic scar reduction. Results are seen instantly and improve over weeks as there is a double effect from the procedure: physical lifting up and out of the scar, and collagen development that often follows from fibroblast stimulation in the dermis by the needle. Not all scars respond equally, and response is governed by type and depth of scar and how disrupted the underlying tissue is; this dictates filler placement and can’t be predicted. I have found broad rolling scars that are distensible when the skin is stretched respond best to fillers, but I have also had success with box car and ice pick scars that are not too narrow. The improvement, whilst varied, is always in my experience evident, and, however slight, is of psychological benefit. These patients have often struggled for years to improve their scars, and resulting expectations are lower than the usual filler patient. They are often so appreciative of small improvements that it is humbling and a useful reminder of the stigma suffered. 

What filler?

Essentially, any proven safe and efficacious dermal filler could potentially be used and selection is governed by the experience and expertise of the practitioner. There are more than 120 fillers on the market in the UK but HAs are the most commonly used.4 I prefer them for acne scars and, whilst I turn to both Galderma and Allergan, I tend mainly to use Emervel Classic for direct lifting out of scars, and Restylane Vital/Vital Light for an all over skin improvement approach. This is because Emervel is firm enough to lift out deep scars but malleable enough to mould if necessary. Restylane Skin Boosters provide an excellent extra string to the bow when looking at skin in poor condition with additional acne scarring, rehydrating rather than volumising to improve overall skin texture. As these are resorbable fillers, the effects are not permanent, although longevity varies. Whilst there are permanent fillers on the market, it would be inadvisable to use them on acne scarring where the option to reverse any unwanted side effects is not available. As well as HA, potential compatible filler types include poly-l-lactic acids (Sculptra), bovine collagen gel, polymethylmethacrylate (Bellafill) and calcium hydroxylapatite (Radiesse).1 Interestingly, Bellafill is the first filler with FDA approval and is licensed for acne scar treatment in the US.5

Poly-l-lactic acids (Sculptra):

Designed to stimulate collagen synthesis over and above that achieved by needle entry, which could give a long-term result if substantial. Can last several years. Requires a series of injection applications over a few months to get results and results are not reversible.1

Bovine collagen gel:

An older solution and not so readily used at clinic level any longer. Bovine in origin rules it out on diet and religious grounds for some patients. Results for depressed rolling scars can be good but only last two to four months. Too soft for any fibrotic scars.6,7

Polymethylmethacrylate (Bellafill):

The only filler to have a licence for acne scar treatment in the US, although only for shallow distensible (rolling) scars. Not yet readily available in the UK.5

Calcium hydroxylapatite (Radiesse):

A cellulose like water-based gel that contains calcium hydroxyapatite in microscopic particles designed to create volume. Not as malleable as HAs but can last up to a year.1


The ideal patient for demonstrating this technique would have scattered deep scars. Figures 2, 3, 4 and 5 show one of the first patients that I treated for acne scarring using dermal fillers. Here I used Juvéderm Ultra to treat the deepest scars seen. The after photos (Figure 3 and 5), taken immediately post procedure, show marked initial improvement which will develop with time. When the needle marks and oedema subside the results are often remarkable. Although Juvéderm Ultra is an excellent choice for many filler procedures, I now tend to use Emervel Classic due to it being more malleable and versatile.


Complication risks are as for any fillers and the patient must be consented in exactly the same way. Risks specific to this treatment appear to be nodules/lumps/visible filler caused by too superficial a placement. Avoid this by careful examination and massaging the area post- treatment. I always give the patient careful instructions for when their oedema has settled. I tell them not to worry about filler that they can feel, only that which they can see and don’t like.

Figure 2: Left cheek before HA filler
Figure 3: Left cheek after HA Filler

I show them how to massage any such areas, but tell them that in an ideal world I will have done a good enough job that they won’t need to touch it. I always add to the consent that when treating very shallow scars a balance has to be found between placing the filler superficially enough to lift the scar but deep enough not to be seen. Ultimately, any stubborn superficial filler could be dissolved with hyaluronidase, but thus far I have not had to do this. You should always warn the patient that they will probably look worse on finishing, but explain that this is temporary. The procedure involves so many needle-points that the combination of this with oedema and potential bruising can be visually displeasing.


The procedure is relatively straightforward, but it takes longer than other filler procedures. It is intricate and the local oedema is substantial, so being methodical about how to inject the area is crucial.

Lifting out individual scars:

1. Clean the area and photograph well. The photographs are an important record and procedure tool. I use an iPad to display them and discuss the scars with the patient, identifying areas/scars causing most distress. Only after this discussion do I start.

2. Begin at the very furthest edge of the treatment area and work methodically into the area scar by scar.

  1. Insert the needle, bevel up under the scar and, when directly under the pitted/dipped area, begin injecting. You should see immediate lifting out of the area. Withdraw and examine. You may need to repeat several times until you have achieved the desired effect.

  2. Refer to photography as necessary; some scars will become visible only at certain angles. If there is a scar on the photograph that you can’t see on the patient, change your angle or reposition the patient.

  3. Some scars have such tortuous tissue sitting under them that when the needle is extruded the filler moves to the side. If this happens, withdraw and massage the filler ensuring that it is not noticeable. Then, use the needle to subcise the scar tissue by moving the needle back and forth in different directions. When you feel that you have broken down some of the scar tissue, attempt to re-site the filler.

  4. Continue across the area, massaging the filler under each scar as necessary. Working methodically across the area is crucial because local oedema will grow and individual scars will become difficult to isolate. You will reach a point where local oedema/entry points make any further procedure impossible. Recognise this point and stop. It may mean that when the oedema has settled there is more that you
    can achieve, but results will already be evident and my experience is that a happy patient is prepared to undertake future treatments. 

For using skin boosters, this is my approach:

1. Prepare as above.

2. Use the normal multi-injection point technique and shallow placement as for standard skin booster treatment.

  1. At individual scars, concentrate several product placements directly under the scar as you would when using a standard HA for lifting a scar.

  2. Massage the entire area afterwards, checking the individual scars are not raised. 


Acne scarring is a debilitating and stigmatising condition, which drives patients to seek out and spend vast amounts of money in their quest to improve the situation. By the time they reach the point of fillers, they have already tried almost all other modes of treatment and have spent thousands of pounds. This is both good and bad. It is positive because they will appreciate small improvements, but could be negative because they can be vulnerable and sometimes have unrealistic expectations. Fillers offer a good solution for many patients but it is important to be realistic; select your patient carefully and guide them as to the improvement that may be achieved.
Show them which scars you believe will benefit from treatment and those which may not, and make sure they are happy with the proposed improvement before starting by conducting a thorough consultation. Take good, clear photos and always warn the patient about how they will look at the end of the treatment. As with all cosmetic procedures, managing expectation is key to happy patients.

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