Experience teaches aesthetic practitioners to become good, but avoiding and managing complications make them great.  Although complications related to dermal filler and toxin injections remain rare, understanding what can go wrong and how it can go wrong are essential when we’re using these products. A well-trained practitioner is able to reduce the sequelae from an adverse event by acting promptly using algorithms and a methodical approach to treatments.


Complications are best prevented with careful planning. Thorough knowledge of both anatomy and the specific characteristics of each filler are critical. The appropriate depth of placement is dependent on the product selected and strongly influences the end result. In order of depth, medium hyaluronic acid products should be injected into the deeper dermis, calcium hydroxyapatite at the dermal-subcutaneous border, and poly-L-lactic acid in fat below the dermis. An injection placed too superficially can produce nodules and an uneven surface; therefore, it is usually preferable to err on the deeper side. 

Before treatment, the physician should clarify the patient’s goals and expectations for both the procedure itself and the subsequent results, and the patient should be given the opportunity to identify desired treatment areas with a mirror. Standardized pre- and post procedure photographs should be taken for documentation. It’s essential to obtain informed consent; this should cover the discussion of potential side effects and all details of pre and postoperative care. The patient should be screened for any medical issues that could affect the application of filler, such as pharmacologic or pathologic clotting disorders, previous vagal episodes, and any history of seizures.

Patients are warned to avoid NSAISs, aspirin, vitamin C, and omega 3 supplements. I usually suggest arnica tablets to reduce bruising risks. It is recommended that patients sleep with the treated area elevated for 1 to 2 nights after injections. Ice water bags applied to treated areas for 5 to 10 minutes per hour will reduce swelling/edema and trauma. I always apply a topical cooling device that reduces pain and bruising after applying topical anesthetic agent before the injections. Using a cannula will reduce bruising. When a bruise appears, it is useful to offer topical applications or sometimes vascular laser treatment to speed resolution. It is well documented that there is a direct correlation between the speed of injections and the number of complications, so it is essential to decrease the speed of injections; I usually spend 5 to 10 minutes per ml of filler, depending on the area injected. Using the smallest gauge needle also slows down the administration of filler. In the event of “lumps and bumps” massage is helpful with many types of fillers, but not all, if they cannot be massaged away after 7 to 10 days, it is possible to use hyaluronidase. It is also possible to extrude many types of filler by using a puncture with a 26-gauge needle or an 11 blade. These same techniques may also be utilized for areas that have been over corrected.

Granulomas are more commonly seen with non hyaluronic acid based products, these may form microspheres that can be extremely difficult to treat. Treatment with hyaluronidase, collagenase, and steroids has demonstrated to help these granulomas. In some instances of granulomas, surgical removal is the definitive treatment. When granulomas undergo delayed inflammation, treatment with oral antibiotics and cyclooxygenase-2 inhibitors may help to minimize the swelling. When injecting the neck and chest, the use of the microdroplet distribution of hyaluronic acid–based products may help to decrease the risk of granulomas. Hyaluronidase is used at 20 to 60 units per 1-mL filler. Triamcinolone is injected to females (2.5 mg/mL) and males (5 mg/ mL) with 0.1 mL per granuloma. The use of calcium hydroxylapatite on the dorsum of the hands could often lead to swelling, and to minimize this I usually place 1 to 1 ½ cc split between both hands and the additional filler is placed at a follow up visit 1 month later if needed.

Infectious complications are another risk of filler injections and can include herpes simplex infection with or without secondary bacterial infection, acute bacterial infections, or biofilm-related events. Practitioners should be using a prep that is effective in treating both gram-positive and gram-negative bacteria. An abscess at a single site suggests contamination was introduced during the injection, whereas the appearance of multiple abscesses indicates the patient was injected with filler material that may likely have been contaminated prior to injection. Sometimes the anesthetic mixed with filler becomes the source of contamination. It’s an option to administer fillers that come pre-mixed with an anesthetic to reduce the risk of contamination. Multi-dose vials of anesthetic should be dated once opened and unused portions should be discarded to reduce the risk of contamination. Also it is not a best practice to store partially used syringes of product for reinjection later. Recurrent abscesses as well as delayed foreign body granulomas are probably related to biofilm, which represents a structured community of micro-organisms encapsulated and protected within a self-developed polymeric matrix, which adheres irreversibly to host tissue or an implanted device. Needle drainage should be performed on any fluctuant lesion and the aspirated material should be sent for culture or PCR analysis. Empiric antibiotic treatment should be initiated with a quinolone plus a macrolide, but the regimen can be altered as dictated by the microbiology results. If the lesion does not respond to antibiotic treatment and hyaluronic acid filler was used, hyaluronidase injection can be performed. As a last resort, consideration can be given to use of pulsed intralesional steroids, once s week for two or three weeks. Biofilm-related complications of filler injections are probably not completely preventable but there are strategies that can be followed to minimize the risk like avoiding injections in the perioral area in patients with an active infection as well as any use of an intraoral injection route. Avoid applying makeup prior to the procedure and for eight hours afterward, and the practitioner should adhere carefully to aseptic injection technique to reduce the bacterial load, I prefer to use chlorhexidine to prepare the skin because unlike alcohol, it has a residual antibacterial effect. Using a smaller gauge needle will minimize surface trauma and bacteria access through the skin. Antibiotic prophylaxis is usually used only in case of immunocompromised patients or when using long-lasting or more permanent fillers as they are associated with a greater risk of biofilm-related complications compared with temporary fillers.

More serious and true complications with fillers include vascular occlusion and necrosis. As one injects any filler, it is critical to watch the surrounding tissue. Upon placement of the needle, aspirate to observe that there is no intravascular placement. If no flash of blood is seen, slowly inject filler and observe the surrounding skin for blanching, vascular flash, reticulated erythema, or a purple/dusky/grey-blue hue. Intense pain in the treatment area may be another sign of vascular compromise.  If any of these situations occur, immediately stop the injection and flood the area with hyaluronidase.  Immediately after this, apply 2% nitropaste and reapply this twice a day. Warm compresses and vigorous massage are also critical to improving the blood flow to the area. Patients should also be given baby aspirin immediately to inhibit platelet aggregation. The immediate use of steroids is also recommended. Doses used range between 20 and 60 mg of prednisone, and this should be continued for several days to decrease the inflammatory component of the injury. Finally, the addition of erectile dysfunction drugs to dilate vessels should be considered. The most serious complications from soft-tissue augmentation include retinal artery occlusion and cerebral embolism. These have been observed primarily with injections of fat but have also been seen with hyaluronic acid products. The risk increases as the volume of injections and the number of injections increase. Decreased visual acuity, pain in the orbit, headache, nausea, dizziness, and ptosis may all signal a significant issue and should be attended immediately. Ophthalmologic consultation should be sought immediately in this case and treatment with hyaluronidase, warm compresses, application of nitropaste, and aspirin should be initiated. Loss of vision, when it occurs, is usually permanent. Before treating the glabella, nasolabial crease, or tear troughs, it is essential to have a great deal of experience and anatomic knowledge to minimize the risk of vascular compromise. For the correction of infraorbital hollow I prefer to inject very small volumes of HA filler superficially above the orbicularis muscle and for correction of true gutter of the tear trough I like to inject higher volumes of HA fillers deep to the muscle along the periosteum. When injecting very superficially always use 32-gauge needle, over injecting with a larger needle in the periorbital area can create visible bumps of linear threading. When performing a tear trough filling procedure, I usually give the patient a mirror to see what we’ve done on one side before switching to the other side. The periocular area can be prone to persistent swelling, one thing to keep in mind is that botulinum toxin in the weeks prior to the filler can at least theoretically prevent the full mechanical pumping action of the orbicularis oculi from helping to get rid of swelling post-filler. I would usually rather inject the filler first and make sure things look good and swelling resolves, and then bring the patient back a few weeks later if I am going to also treat them with a neuromodulator. Some experienced injectors believe that the higher G’ fillers lead to less overall swelling. In some cases of persistent periocular edema following fillers, hydrochlorothiazide may prove to have some benefit, but usually in the more significant cases, hyaluronidase is used to get rid of the filler that is pulling in the edema or potentially compressing ductal structures. Filling of the temporal fossa should be done at the periosteal plane to avoid the superficial temporal artery. Injections into the forehead also need to be in the deep planes to avoid the superficial vessels that are abundant in the region.  However, in the glabellar area, a high-risk danger zone, placement of any filler must be carefully and more superficially injected to avoid vascular occlusion and necrosis of the supraorbital and supratrochlear arteries. Other significant danger zones include the angular artery at the base of nasal labial fold and the superficial labial artery at the corner of the mouth. One other significant potential hazard is the dorsal nasal artery located at the root of nasal/glabellar groove, and similar care with slow injection technique, attention to anatomy, observation of patient pain or discomfort, and cannula use will reduce these risks.


One of the most comforting features about adverse events with neuromodulators is that they are typically transient. Because the mechanism of action of the toxin involves a temporary blockage of the release of the neurotransmitter acetylcholine, its effects are also transient. These proteins are used to treat a range of conditions including hyperhidrosis, migraines, cervical dystonia, spasticity, as well as for their cosmetic indications. In aesthetic practice, the most common adverse events are injection related. These include bruising, swelling, edema, needle marks, pain, and bruising. In addition, toxin-related events such as ptosis, asymmetry, diplopia, and dysphagia are temporary in nature. As with any injection, it is imperative to provide each patient with informed consent and pre- and post treatment instructions. Photographs should be obtained which help demonstrate to the patient not only the benefits of the treatment but also to show them that perceived new lines and folds, as well as vascular structures and nevi, were present before the injections.

The most common complication associated with botulinum toxin injections in the glabella and frontalis is brow or lid ptosis. The brow ptosis typically occurs when the frontalis muscle is over treated or when the levator palpebrae muscle is inadvertently injected. Negating the levator function of the frontalis can result in a brow that becomes ptotic. To minimize this avoid treatment of the bottom 1/3 of the brow and in some patients avoid brow injections entirely. During the consultation, it is important to discuss the brow and obtain an understanding of the patient’s desired shape. In general, females prefer an arched brow with the peak of the arch located at the lateral aspect of the iris. Males tend to prefer to have a flat brow that does not feminize their face.  It is prudent to use less toxin than needed and ask the patient to revisit  in 10 to 14 days for repeated treatment. Injections of toxins into the tail of the brow can help to lift the forehead and is an excellent way to avoid brow descent. True lid ptosis occurs when the toxin is injected into the levator palpebrae superioris muscle. It is believed that injections that are placed too inferiorly in the supratrochlear region can increase the risk of this occurrence. It is important to avoid massages for a few days after injections with toxins. Eye drops with naphazoline or apraclonidine 0.5% could be used, this is a quick fix, leaving patients happier until the effects of the toxin wear off. In skilled hands, ½ to 1 U of botulinum toxin placed in the medial and lateral tarsus can also lift a lid ptosis. Another complication associated with toxin injections involves cheek paralysis or palsy. To avoid this, it is important to stay more superolateral with the injections around the crow’s feet. Occasionally, I will place small amounts of toxin (4–8 U or onabotulinum toxin or 10–20 of abobotulinum toxin) in the upper cheek for lateral lines extending from the crow’s feet. Higher doses here can lead to zygomatica minor muscle paralysis and result in a lip droop especially in older individuals. A small amount could be added to the infraorbital portion of the orbicularis muscle if it is hypertrophic. Patients should be warned that this may result in more open eyes that subsequently feel dry and may be difficult to close. To minimize the risk of dry eyes, it is critical to avoid infraorbital injections in patients with a history of transconjunctival blepharoplasties. Advanced uses of botulinum toxin include treatments of the lower half of the face and neck. These areas are laden with opportunities for adverse events. Because of this, it is important to achieve relaxation in a gradual manner rather than paralysis in an immediate one. Oral motor insufficiency may be seen with botulinum toxin injections around the orbicularis muscle. It is important to explain to patients when using toxins in this area that certain oral insufficiencies can occur. These may include difficulty drinking through a straw, whistling, playing the trumpet, and difficulty saying P and B’s. An addition, adverse event may arise when placement of the toxins is uneven. This may result in an uneven smile or drooling. To minimize this risk, it is advisable to use small doses of toxins and to avoid injections into the lateral 1/3 of the lip. Even among expert injectors, treatment DAO may result in treatment of the depressor labii inferioris. This will result in a crooked mouth that is accentuated when smiling. This complication may be avoided by injecting small amounts of toxin and targeting the DAO in a gradual manner. Having patients move their mouth and palpating the DAO muscle help identify the correct placement of toxin. The only treatment for this type of complication is to intentionally treat the contra lateral depressor labii inferioris to produce a symmetric mouth. Injections of neuromodulators into the neck combined with injections into the mentalis muscle and DAO can lead to dramatic albeit temporary neck tightening and lifting. Injections of the platysma muscle can result in significant face lifting and relaxation of the bands that are one hallmark of an aging face. However, injections of toxin that are high dose or that are injected into the deep muscles of the neck may result in dysphagia. Treatment involves insertion of a feeding tube for those who are severely affected.

Patients expect aesthetic practitioners to enhance and enrich their physical appearance. Although it is vital to learn the advanced techniques necessary to do so, it is equally important to understand complications and adverse events that may arise. The best treatment for an adverse event is avoidance but it is imperative to know how to treat them when they occur.


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