Risks and Side effects of a Dermal Filler Treatment

Risks and Side effects of a Dermal Filler Treatment:

Dermal Filler treatments are now of the most popular remedies for anti-ageing and facial rejuvenation, but despite the safety of HA Dermal Fillers these treatments still come with some potential side effects and risks. It is important if you can deliver a treatment, that you feel confident to manage these side effects and most importantly that you learn how to spot them immediately, therefore we include a full complications & reversal section within our Foundation Level Derma Filler Course.

Although the injection of dermal filler is classed as minimally invasive and indeed carries less regulation than the administration of botulinum toxin, adverse effects may be more serious, with greater potential for long term & irreversible damage.

Injection site reactions tend to be the most common complication reported, mainly due to immediate trauma to the skin from the process of injection. However, there are many more to consider!


Complications of dermal fillers can be broadly divided into:

  • Normal transient and predictable complications
  • Technical errors
  • Inflammatory complications (contamination by infectious agents and immune responses to treatment).

Normal transient and predictable complications are:

  • Post-injection pain,
  • Redness
  • Swelling
  • Hyaluronic acid (HA) hydroscopic swelling,
  • Minor nodules
  • Palpability and transient visibility.

*These are expected incidents and are easily managed.  They will be observed and discussed in your practical training.

Technical errors

Injection of an inappropriate volume of filler

Inaccurate depth of filler injection including the Tyndall Effect

Injecting in the wrong location and incorrect filler choice

Under or over-correction.

*These are expected incidents and are easily managed.  They will be observed and discussed in more detail in your practical training.


Inflammatory complications (contamination by infectious agents and immune responses to treatment).

  • Infection
  • Vascular compromise & occlusion
  • Necrosis
  • Longer term nodules or granulomas
  • Hypersensitivity.

Swelling, erythema, and tenderness following dermal filler injections – have been widely reported  All dermal fillers present in the market are able to provoke inflammatory reactions including hyaluronic acid (HA) but particularly collagen, silicone, polylactic acid, polyacrylamide, and methacrylate, which are not covered in this qualification nor will it allow you to practice with these types of fillers.

Hypersensitivity reactions can occur any time up to 72 hrs after injection but may be late as several weeks post injection and can persist for months. It has been suggested that biological/patient factors (e.g., previous skin or systemic conditions such as infections and trauma), patients who are more atopic (prone to allergies), injection technique (e.g., filler volume, repeat treatments, intramuscular implantation), and the different properties of HA fillers may explain these reactions.


Management – When an allergen enters a person’s body or encounters their skin, the immune system releases histamines, which bind to H1 receptors throughout the body. Once bound, they trigger several typical allergic reactions, such as vasodilation, urticaria and smooth muscle contraction.


Excessive swelling or obvious signs of hypersensitivity in the first 72 hours can often be managed with oral antihistamines. These act by blocking the H1 receptors and preventing the histamines from binding to them thereby dampening down the inflammatory response.


If a person is unresponsive to anti histamines, they are likely to require a corticosteroid to alleviate the inflammatory signs. A corticosteroid will mimic the effect of cortisol, which is a stress hormone normally released by the adrenal glands to minimise the effects of inflammation. The recommended anti histamine for inflammatory response in the first instance is prednisolone – the use of this will be covered in your practical training.


Hyaluronidase (an enzyme that breaks down dermal filler molecules) may also be injected to remove the allergen (the dermal filler) in some cases. In the section we will cover the theory behind Hyaluronidase & the use of this will be covered in your practical training.


Although late onset or prolonged hypersensitivity does not demand the urgent attention that vascular occlusion requires, hypersensitivity can be a problem that causes considerable patient distress, especially if there is significant angioedema (swelling).


Delayed onset nodule as ‘a visible or palpable unintended mass which occurs at or close to the injection site of dermal filler’. Also referred to as Granuloma formation is the body’s attempt at removing foreign material and can happen after any dermal filler. Histologically, a granuloma is composed of histiocytes and epithelioid cells. They are slightly different from nodules which are isolated single ‘lumps’ of product surrounded by a fibrous capsule, becoming palpable within weeks of treatment. Granulomas by contrast are usually a late complication of filler injection. Injections in highly mobile areas such as the lips carry an increased risk of delayed-onset nodules. example Delayed Onset  Nodule /Granuloma

Granuloma or Delayed Onset Nodule


Excessive swelling caused by Lip Filler injections

Prevention – Injection pressure, needle diameter and number, depth and angle of penetration sites can all be factors that may increase the risk of developing a nodule, but the following are the key things you can do to minimise the risk.

Select the correct product for the indication that you are treating. Always use a product that has evidence for its use and safety documentation. A product that is too viscous (thick) has may cause a ‘mass’ under the skin as flexibility may be compromised.

Ensure you are using an aseptic technique when administering dermal filler injections. Bacteria are everywhere and whilst some are good for us others are harmful. Bacteria, viruses, and other microorganisms that cause disease are called pathogens. To protect patients from harmful bacteria and other pathogens during medical procedures, healthcare providers use aseptic technique. Aseptic technique means using practices and procedures to prevent contamination from pathogens. It involves applying the strictest rules to minimize the risk of infection. Healthcare workers use aseptic technique in surgery rooms, clinics, outpatient care centres, and other health care settings.

Reduce trauma by using the correct gauge needle or cannula appropriate for the chosen product. This is covered within your practical training

Management A lump presenting at the time or within hours of treatment is likely to be due to product misplacement, migration or simple swelling. Massage should be the immediate response in this case.

Lumps, masses or swelling along with features of acute inflammation (redness, heat, tenderness, pain and swelling) presenting after 3-4 days and before 14 days is likely to be due to infection and should be dealt with as such.

The initial management of persistent and troublesome nodules is with firm massage and diffusion using saline and/or lidocaine, matching the volume of product injected which you wish to disperse.

If the nodule is visible and sitting in the upper layers of the lip tissue extrusion may also be attempted using a sharp needle and attempting to squeeze out the offending lump, although caution needs to be adopted not to cause further problems with fibrosis or scarring. The use of oral steroids can be considered as treatment, but surgical excision is recommended for larger, well-defined lumps.

Some DONs (delayed onset nodule) may be palpable (able to be touched) or felt within the skin but not visible and they may be best left alone with watchful waiting.

Skin infections can occur following any procedure where the normal integrity of the skin is compromised. In this case, we mean through piercing of the skin with a needle or cannula for the purposes of aesthetic procedures. The reported incidence of infection following this type of procedure is less than 0.2%, so it remains a rare occurrence within our field of practice.

Acute Infection   

Acute infection is most likely to be caused by the introduction of bacteria at the time of injection. This could be due to a poor aseptic technique, lack of appropriate skin cleansing, or due to the patient having a pre-existing infection. An acute infection will present with localised symptoms such as redness, inflammation, heat and tenderness.  In severe infections, the patient may also have systemic symptoms such as fever, nausea and rigors.



Biofilms (infection)

Biofilms are a collective of one or more types of microorganisms that can grow on many different surfaces. Biofilm formation begins when free-floating microorganisms such as bacteria meet an appropriate surface and begin to put down roots, so to speak. Biofilms can grow on implanted medical devices such as prosthetic heart valves, joint prosthetics, catheters, pacemakers and of course, dermal fillers.

It must be noted that the development of biofilms in aesthetics is a rare event, but they can cause the formation of nodules and abscesses, they often persist for months and cause great anxiety to the patient.

The reason that biofilm formation is a great cause of concern is that, within a biofilm, bacteria are more resistant to antibiotics. Biofilms causing infections are progressive, and in some cases can become a chronic problem. They develop within weeks after the administration of the filler, and present as erythematous, mildly tender nodules.

In most cases, the filler needs removal, either by extrusion or hyaluronidase, alongside a course of broad-spectrum antibiotics.

Prevention – A full medical history should be taken prior to any procedure, and in the case of any current or recent infections, treatment should be delayed. It is also important to illicit any information that reduced the client’s immunity (pre-existing illness or medication) and puts them at higher risk of infection.

Dermal filler injection should be an aseptic procedure.  This means the use of sterile packs, with sterile gloves, and adherence to standard infection control precautions.

The area to be injected should be thoroughly cleaned with an appropriate skin disinfectant product. And repeatedly cleaned at various points throughout the procedure.

Dermal fillers are single patient, single use items.  This means that they can be used on one patient, on one occasion only. Sharing of filler syringes between patients, or keeping a part used syringe of filler for use on the same patient, is a huge infection risk & considered back practice.

Ensure the needle or cannula is not contaminated during injection procedures, do not let the needle or cannula touch the skin except during actual injection and do not wipe excess product from the needle tip with gauze.

Aftercare advice should be adhered too, patients should not touch the area that has been treated for at least 12 hours, and makeup or any skincare products should also be avoided for 12 hours.

Management – Acute infections are typically due to common pathogens present on the skin such as Staphylococcus aureus or Staphylococcus epidermidis. First line treatment for these bacteria should be an appropriate antibiotic, such as Flucloxacillin or Clarithromycin, prescribed for a seven day period.

If there is no response at 48-72 hours, a change in antibiotic regime should be considered and swab for microbiology, culture and sensitivity if available.

If an abscess forms, and the patient remains symptomatic, referral on to a practitioner who can perform incision and drainage will be required. In the case of systemic symptoms with any infection, the patient should be advised to take paracetamol and ibuprofen for pain and fever management. We would recommend reviewing the patient every 48 hours in the case of infection, and good documentation, including photographs should be kept of your interventions.

In most cases, the filler needs removal, either by extrusion or hyaluronidase, alongside a course of broad-spectrum antibiotics.

Vascular Occlusion

The most serious complication of dermal fillers are vascular complications, which usually occur as a result of accidental intravascular injection of dermal filler into an artery, or compression, necrosis. Necrosis can be defining as “The death of most or all of the cells in an organ or tissue due to disease, injury, or failure of the blood supply.

Obstruction of blood supply can cause blindness; for example, inadvertent bolus injection into the angular artery has the potential to cause blindness via retrograde flow of filler into the ophthalmic artery. The incidence of this is higher with injection in the upper face, in the glabella area and the nose.

The overall reported incidence of vascular occlusion in dermal filler injections is 1 in 100,000 cases. However, it is widely recognised that the prevalence of vascular occlusions following injection of soft tissue filler is increasing due to the rising popularity for these treatments. Many cases of vascular compromise occur immediately with injection, and the practitioner will see blanching of the skin distal to the site of occlusion and livedo reticularis (a mottled, purple discolouration), sometimes accompanied by serve pain. However, symptoms may take several hours to present or evolve over a period of a few days.



Recognising Vascular Occlusion


Blanching – the area may initially look pale due to the reduction of blood supply. This area of blanching may spread and become irregular in shape.

Poor capillary refill- This should be tested by pressing firmly on the area affected for 5 seconds before releasing. If normal colouring does not return within a few seconds, suspect a vascular occlusion. It is wise to test the unaffected side of the face at the same time, to compare capillary refill times.

Disproportionate pain– If a patient complains of sudden or escalating pain during treatment or in the subsequent hours after treatment, this should alert the practitioner to the possibility that a vascular occlusion has occurred.

Livedo reticularis – this is a mottled, purple-ish appearance that can often be mistaken for bruising.

Coolness of the skin – When the blood supple has been affected, the tissues are nto being perfused so the temperature will be reduced, this will not be apparent immediately following injection, but can be a good indicator in a late presentation of vascular occlusion.



First signs of Occlusion



Vascular Occlusion Day 4

Prevention – Management of artery occlusion is difficult; therefore, the best method is avoidance.

Aspiration prior to every injection is the single most important prevention measure to take.  Aspiration means to draw breath, or air from a needle. This simple process can make a big impact. It protects you from hitting a blood vessel or artery and accidentally injecting filler into one, which can result in limited blood supply and if left untreated tissue death.

Even though false-negative results have been found in around 50% or more of aspiration tests, it is a very quick test, and may mean the difference between a positive and negative outcome.

The use of cannula use has also been shown to reduce the risk of vascular occlusion and avoiding small bore needles can reduce the likelihood of the needle entering the vessel to deposit filler intravascularly.

Injecting slowly and using small volumes of product at a time can also reduce the risk of depositing large volumes of product within or on top of a vessel

A good knowledge of vascular structure of the face is central to enabling you to use dermal fillers effectively while ensuring that risk of side effects is kept to a minimum.


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