Filler complications glossary: 49 terms, each defined in one sentence

What is a filler complication?

A filler complication is any unwanted effect of a dermal filler injection, and doctors sort complications by when they appear and by whether they are inflamed. Most filler treatments go smoothly, and a review of dermal filler adverse events found that most reactions are mild and short-lived and that serious events are rare (Funt and Pavicic, 2013).

Filler complication: A filler complication is any unwanted effect of a dermal filler injection, ranging from mild, short-lived effects such as bruising and swelling to rare serious events such as a blocked blood vessel (Funt and Pavicic, 2013).

Early filler complication: An early filler complication is one that appears within hours to several days of the injection, such as bruising, swelling, an early lump or a blocked blood vessel (Funt and Pavicic, 2013).

Delayed filler complication: A delayed filler complication is one that appears weeks to years after the injection, such as a delayed-onset nodule, a granuloma or filler migration (Funt and Pavicic, 2013).

Each entry below is one self-contained sentence, followed by a link to the full guide where SkinRev Lab has one. The terms are grouped by type: blood vessels, lumps, infection and immune reactions, movement and overfill, appearance, filler materials, correction and injection technique. For how filler problems are assessed and treated, see filler correction at SkinRev Lab. This glossary is general information; your doctor will advise on your own situation.

Blood-vessel terms: vascular occlusion, blanching and skin necrosis

Filler vascular occlusion is a blockage of blood flow caused by filler in a blood vessel, and it is the most urgent filler complication. Serious filler events such as this are rare (Funt and Pavicic, 2013). The five terms below describe vascular occlusion and its signs.

Vascular occlusion: Filler vascular occlusion is a blockage of blood flow that happens when filler is injected into a blood vessel, and it typically shows as blanching, mottled skin and pain during or soon after the injection (Jones and colleagues, 2021), signs that mean go to an emergency department now.

Blanching: Blanching after filler is a sudden pale or white patch of skin near the injection site, which can signal that blood flow to that area has been interrupted (Jones and colleagues, 2021) and means go to an emergency department now.

Livedo (mottling): Livedo after filler is a net-like, mottled, dusky pattern on the skin that can accompany or follow blanching and suggests reduced blood flow (Jones and colleagues, 2021), a sign that means go to an emergency department now.

Skin necrosis: Skin necrosis after filler is the death of an area of skin that has lost its blood supply, for example because filler has blocked a blood vessel (Funt and Pavicic, 2013), and skin that turns pale, dusky, mottled or dark after filler means go to an emergency department now.

Filler-related vision loss: Filler-related vision loss is a sudden loss of sight, usually in one eye, during or shortly after a filler injection, caused by filler reaching the arteries that supply the eye (Jones and colleagues, 2021), and any vision change after filler means call 995 or go to an emergency department now.

If skin turns pale, dusky or mottled, pain is severe or escalating, or vision changes after filler, go to an emergency department now. For the warning signs in a high-risk area, see nose filler complications.

Lump and nodule terms: from filler lump to granuloma

A filler lump is any bump felt or seen after filler, and doctors classify lumps by when they appear and whether they are inflamed, because that decides the treatment. The five terms below cover the main types.

Filler lump: A filler lump is any bump that can be felt or seen after a filler injection, and when it appears within hours it is likely to be due to misplaced product (King and colleagues, 2016).

Non-inflammatory nodule: A non-inflammatory filler nodule is a cool, firm, well-defined lump that is not red or tender, usually caused by filler that is misplaced, too superficial or concentrated in one spot (King and colleagues, 2016).

Inflammatory nodule: An inflammatory filler nodule is a lump that is red, swollen, tender or warm, which points to infection or an immune reaction and needs a doctor's assessment (Jones and colleagues, 2021).

Delayed-onset nodule: A delayed-onset nodule is a visible or palpable lump at or close to a filler injection site that appears more than about four weeks after treatment (King and colleagues, 2016; Jones and colleagues, 2021).

Foreign-body granuloma: A foreign-body granuloma after filler is a firm lump formed by immune cells walling off filler material, typically months to years after injection, and it can be confirmed only by examining tissue under a microscope (Funt and Pavicic, 2013; King and colleagues, 2016).

Do not massage or squeeze a lump unless your doctor advises it. For causes and care, see filler lumps and nodules.

Infection and immune-reaction terms

A filler infection is a bacterial infection at or near a filler injection site, and it is told apart from an immune reaction by its timing, heat, pain and course. The five terms below describe infections and immune reactions after filler.

Filler infection: A filler infection is a bacterial infection at or near a filler injection site, typically showing as red, hot, increasingly painful swelling from about day 3 to day 14 after treatment (King and colleagues, 2016).

Abscess: A filler abscess is a collection of pus at a filler site, which can appear from about one week to several years after the injection (Funt and Pavicic, 2013).

Biofilm: A filler biofilm is a community of bacteria that coats filler material inside a protective layer, which makes it hard to culture and to treat, although its role in causing filler nodules is still debated (King and colleagues, 2016; Jones and colleagues, 2021).

Delayed hypersensitivity reaction: A delayed hypersensitivity reaction to filler is immune-driven swelling, redness and firmness that typically appears about a day to several weeks after injection and can persist for months (Funt and Pavicic, 2013).

Angioedema: Angioedema after filler is rapid allergic swelling that appears within hours of the injection (Funt and Pavicic, 2013), and swelling of the lips, tongue or throat or any difficulty breathing means call 995 or go to an emergency department now.

Spreading redness with fever, or swelling of the lips, tongue or throat with difficulty breathing, means go to an emergency department now. For swelling that appears late, see filler swelling: what is normal.

Movement and overfill terms: migration, overfilled face and pillow face

Filler migration is filler found somewhere other than where it was injected, while overfill terms describe too much filler for the area. The six terms below are the ones most often confused.

Filler migration: Filler migration is the presence of filler in a location other than the one it was injected into, and it is classed as a delayed filler complication (Funt and Pavicic, 2013). See filler migration.

Lip filler migration: Lip filler migration is filler that has moved out of the lip itself, usually into the skin above the upper lip where it forms a ledge, and migrated filler is a recognised reason for dissolving (Murray and colleagues, 2021). See lip filler migration.

Overcorrection: Filler overcorrection is the placement of more filler than an area needs, and it is a recognised cause of non-inflammatory lumps (Funt and Pavicic, 2013).

Facial overfilled syndrome: Facial overfilled syndrome is facial distortion caused by repeated or wrongly placed filler, which becomes more obvious with facial expression and is often underdiagnosed (Lim, 2023). See signs of too much filler.

Pillow face: Pillow face is an informal name for a puffy, rounded, overfilled look of the midface, one of the areas in which a review of facial overfilled syndrome describes volume overload (Lim, 2023). See pillow face correction.

Filler fatigue: Filler fatigue is an informal term, not a medical diagnosis, for a face that looks heavier or less like itself after repeated filler, a pattern linked to relying on filler as the only treatment (Lim, 2023). See filler fatigue.

Appearance and recovery terms: Tyndall effect, malar oedema and bruising

The Tyndall effect is a bluish tint from hyaluronic acid filler placed too close to the skin surface, and it is one of several visible effects that are not dangerous but may need correction. The five terms below describe what can be seen after filler.

Tyndall effect: The Tyndall effect after filler is a bluish discolouration of the skin caused by light scattering from hyaluronic acid filler that sits too close to the surface (Funt and Pavicic, 2013). See Tyndall effect after filler.

Superficial placement: Superficial filler placement is filler sitting closer to the skin surface than intended, which can show as visible bumps, an uneven surface or a blue tint (Funt and Pavicic, 2013).

Malar oedema: Malar oedema after filler is long-lasting fluid swelling across the upper cheek and under the lower eyelid, linked to filler in the under-eye hollow impairing lymphatic drainage (Funt and Pavicic, 2013). See tear trough filler problems.

Bruising: Bruising after filler is a discoloured mark caused by a needle or cannula injuring a small blood vessel, and it is a common, mostly mild and short-lived effect of all fillers (Funt and Pavicic, 2013). See bruising after filler.

Post-treatment swelling: Post-treatment swelling after filler is a normal short-term response to the injection that relates to the volume and technique used and usually resolves within a week (Funt and Pavicic, 2013). See dermal filler aftercare.

Filler material terms: hyaluronic acid, biostimulators and permanent fillers

Hyaluronic acid filler is the only filler type that can be dissolved with an enzyme, so the material matters when a problem needs correcting. Brand names appear below only to name the linked guides.

Hyaluronic acid (HA) filler: Hyaluronic acid filler is a gel of cross-linked hyaluronic acid, and it is the filler type that the enzyme hyaluronidase is used to dissolve (Murray and colleagues, 2021).

Non-HA filler: A non-hyaluronic acid filler is a filler made of any other material, and its nodules are managed differently because hyaluronidase is used for hyaluronic acid filler only (King and colleagues, 2016).

Biostimulator: A biostimulator, or collagen stimulator, is an injectable whose particles prompt the body to build its own collagen over weeks to months, and it does not respond to hyaluronidase, which breaks down hyaluronic acid (Murray and colleagues, 2021).

PLLA: PLLA (poly-L-lactic acid) is a collagen-stimulating filler material, and granulomatous nodules after it have been described up to 14 months or more after injection (King and colleagues, 2016). See the Sculptra guide.

PCL: PCL (polycaprolactone) is a collagen-stimulating filler material made of microspheres, and it does not respond to hyaluronidase, which breaks down hyaluronic acid only (Murray and colleagues, 2021). See the Ellansé guide.

CaHA: CaHA (calcium hydroxylapatite) is a filler material that gives immediate volume and later stimulates collagen, and it does not respond to hyaluronidase, which breaks down hyaluronic acid only (Murray and colleagues, 2021). See the Radiesse guide.

PDLLA: PDLLA (poly-D,L-lactic acid) is a collagen-stimulating particle used in some skin boosters, and its particles do not respond to hyaluronidase, which breaks down hyaluronic acid only (Murray and colleagues, 2021). See the Juvelook guide.

Collagen filler: A collagen filler is a gel of purified animal collagen that adds volume straight after injection and is gradually absorbed, and it does not respond to hyaluronidase, which breaks down hyaluronic acid only (Murray and colleagues, 2021). See collagen injection complications and Deusaderm complications.

Permanent filler: A permanent filler is a filler the body does not break down, such as silicone, and nodules after permanent and semi-permanent fillers are often foreign-body granulomas on biopsy (Jones and colleagues, 2021).

Correction terms: hyaluronidase, dissolving and ultrasound mapping

Hyaluronidase is the enzyme doctors use to dissolve hyaluronic acid filler, and most correction terms describe how, where and when it is used. At SkinRev Lab, correction is carried out by Dr Sin Yong after a consultation.

Hyaluronidase: Hyaluronidase is an enzyme that breaks down hyaluronic acid, and in aesthetic medicine it is mainly used to dissolve cross-linked hyaluronic acid filler (Murray and colleagues, 2021). See hyaluronidase side effects.

Filler dissolving: Filler dissolving is the injection of an enzyme (hyaluronidase) into hyaluronic acid filler that is misplaced, excessive, migrated or blocking a blood vessel (Murray and colleagues, 2021). See dissolving filler in Singapore.

Treat to effect: Treat to effect is the practice of giving hyaluronidase in amounts guided by the response, with reassessment and repeat treatment if needed, instead of a fixed dose (Murray and colleagues, 2021).

Intradermal test: An intradermal test before hyaluronidase is a small amount of the enzyme placed in the skin to look for an allergic reaction, and a guideline advises against using it as a routine screen in people with no allergy history and says people with a history of marked reactions to bee or wasp stings should be tested at an allergy clinic (Murray and colleagues, 2021).

Ultrasound filler mapping: Ultrasound filler mapping is a scan that can show earlier filler and map nearby blood vessels before a new filler treatment, and can show filler and the surrounding tissue when a problem arises (Schelke and colleagues, 2018). See the ultrasound filler mapping video.

Ultrasound-guided dissolving: Ultrasound-guided dissolving is the injection of hyaluronidase directly into a filler deposit while it is viewed on ultrasound (Schelke and colleagues, 2018).

Filler correction: Filler correction is the medical assessment and treatment of an unwanted filler result, which for hyaluronic acid filler usually means dissolving misplaced, excess or migrated gel (Murray and colleagues, 2021). See filler correction.

Refilling after dissolving: Refilling after dissolving is the placement of new filler once hyaluronidase has done its work, and a guideline advises waiting at least two weeks, or longer if swelling persists (Murray and colleagues, 2021). See filler after dissolving.

Injection technique terms: cannula, aspiration and injection plane

A blunt cannula, aspiration and the injection plane are technique terms that describe how doctors lower the risk of filler entering a blood vessel. No technique removes the risk entirely, which is why the warning signs still matter. The three terms below often come up in a consultation.

Blunt cannula: A blunt cannula is a flexible, blunt-tipped tube used in place of a sharp needle to place filler, and studies suggest it is less likely than a needle to pierce a blood vessel (Jones and colleagues, 2021).

Aspiration: Aspiration before filler is the step of drawing back on the syringe to check for blood before injecting, and a negative result does not rule out that the tip is inside a vessel (Jones and colleagues, 2021).

Injection plane: The injection plane is the tissue layer in which filler is placed, such as on the bone or within the skin, and choosing the plane away from an area's main vessels is a core part of lowering risk (Jones and colleagues, 2021).

The same task force advises slow injection with low pressure and small amounts per pass in high-risk areas (Jones and colleagues, 2021). Useful questions before any filler are which product is being used, at what depth, and what the plan is if the skin changes colour. A doctor who suggests less filler, or none, is often protecting your result.

Which filler complication terms mean urgent care?

Vascular occlusion, filler-related vision loss, angioedema of the lips, tongue or throat, and spreading infection with fever are the filler complications that need emergency care; most other terms in this glossary describe problems that can wait for a doctor's review. The table groups the terms by how quickly to act.

At SkinRev Lab, Dr Sin Yong, medical adviser, assesses non-urgent filler problems wherever the filler was done, using a history, an examination and ultrasound mapping where useful. Options include waiting, and correction is priced at consultation.