Dermal fillers have a good safety record when they are injected by qualified professionals, and most reactions are mild and temporary. Complications remain possible, however, and some require urgent treatment. Knowing how to tell a normal reaction from a warning sign helps patients act quickly and helps clinics manage risks.

Understanding Dermal Filler Complications

Complications can be classified according to when they appear:

Immediate, during or within hours of the injection, such as vascular occlusion or an allergic reaction.
Early, within days, such as infection, significant swelling or lumps.
Late, weeks or months later, such as nodules, migration or delayed inflammatory reactions.

Normal reactions include mild swelling, redness, tenderness and small bruises at the injection points, which usually settle within a few days to two weeks.

Early Warning Signs to Watch For

Swelling that increases after 48 to 72 hours rather than decreasing.
Redness, warmth and pain that worsen, sometimes with fever.
Firm, painful lumps.
A visible bluish tint under thin skin (Tyndall effect), often in the tear trough.
Asymmetry that persists after swelling has resolved.

Serious or Urgent Signs Requiring Immediate Attention

Blanching or whitening of the skin during or shortly after the injection.
A mottled, purplish or dark pattern spreading on the skin.
Severe pain out of proportion to the procedure.
Changes in vision, eye pain or drooping eyelid.
Difficulty breathing, swelling of the face or throat, which may indicate a severe allergic reaction: call 911.

Vision changes or signs of vascular occlusion require immediate medical care. Vascular occlusion caused by an HA filler is treated urgently with hyaluronidase by the injector.

Causes of Dermal Filler Complications

Injection into or near a blood vessel.
Insufficient asepsis or contaminated products.
An inappropriate product, depth or volume for the area.
Patient factors, such as an immune reaction, a recent infection or an undeclared condition.
Products of unknown origin, particularly those sold to the public online. See our article on DIY fillers.

Reducing the Risk of Complications

Choose a qualified injector. In Canada, who may inject fillers depends on the province and the professional college.
Make sure the clinic uses products from legitimate supply channels, such as the JUVÉDERM®, RESTYLANE®, BELOTERO®, TEOSYAL® or REVANESSE® ranges, with recorded lot numbers.
Share your complete medical history.
Follow aftercare instructions. See what not to do after fillers.

For clinics, having hyaluronidase available, a written complication protocol and trained staff is essential.

When and How to Seek Professional Help

Contact your injector as soon as you notice an unusual sign, even outside office hours. If you cannot reach them and the signs are serious, go to the emergency department and mention that you received a filler, specifying the product if possible. In Canada, patients and healthcare professionals can report any suspected adverse reaction to Health Canada through the Canada Vigilance Program. Clinics can find all products in our dermal fillers category.

References

American Academy of Ophthalmology. (n.d.). Complications of hyaluronic acid fillers. Retrieved from https://eyewiki.org/Complications_of_Hyaluronic_Acid_Fillers

Sclafani, A. P. (2008). Safety, efficacy, and utility of hyaluronic acid fillers in the periocular region. Seminars in Plastic Surgery, 22(2), 120–125. https://www.sciencedirect.com/science/article/abs/pii/S0738081X08002514

Urdiales-Gálvez, F., et al. (2023). Complications after filler treatment: prevention, assessment, and treatment. Journal of Clinical and Aesthetic Dermatology. https://journals.sagepub.com/doi/10.1177/20501684231197717

Common Questions About This Topic

What is considered a normal reaction after dermal fillers?

Mild swelling, redness, tenderness and small bruises at the injection points, which improve over a few days and usually resolve within two weeks.

How soon after treatment can complications appear?

Some appear immediately, such as vascular occlusion. Others appear within days, such as infection, or weeks to months later, such as nodules or delayed inflammatory reactions.

Can dermal filler complications be treated?

Yes, most of them. HA fillers can be dissolved with hyaluronidase, infections are treated with antibiotics and inflammatory reactions with appropriate medication. Early treatment gives the best results.

Are some filler types more likely to cause complications?

The risk depends more on the injection technique, the area and the product’s suitability for the zone than on a single type. However, HA fillers have the advantage of being dissolvable, which simplifies management.