Delayed immune mediated adverse effects to hyaluronic Acid fillers: report of five cases and review of the literature

Impurities in Hyaluronic Acid Dermal Fillers? A Narrative Review on Nonanimal Cross-Linked Fillers

Importance: Nonanimal cross-linked hyaluronic acid (HA) dermal fillers are among the most versatile tools in minimal invasive esthetic medicine. Filler injections aim to volumize, provide contour, and reduce wrinkles and skinfolds. In the hand of the experienced user, HA fillers have an excellent safety profile. Nevertheless, adverse events have been reported related to poor injection techniques, infection, and immune reactions. Observations: In this review, the focus is on filler impurities. Impurities can originate from the fermentation process, crosslinking, packaging, and contamination. Impurities consist of particular and nonparticular matter. We discuss possible risks for the patient to be treated with HA fillers. Conclusions and Relevance: Impurities of dermal fillers bear a potential risk for patients, such as delayed autoimmune and inflammatory reactions, biofilm formation, and exposure to leachable Endocrine Disrupting Chemicals. Amount and quality of impurities can be considered as one of the quality parameters of commercially fillers. Considering patient safety, filler impurities should be further reduced.

Hyaluronic Acid Fillers and ASIA Syndrome: Case Studies

A continuous increase in the popularity of esthetic procedures with the use of substances as HA has been observed for many years, which might be contributing to an increase in the number of adverse events. The autoimmune/inflammatory syndrome induced by adjuvants (ASIA) can be provoked by hyaluronic acid (HA), which belongs to substances meeting the criteria of adjuvants. Mechanisms of the innate and acquired immune response are activated, leading to the dysregulation of T and B lymphocytes, inability to recognize one's own antigens, inflammation, damage to one's own tissues, and ultimately to autoimmunity. The objective of this article is to present a case-series study of patients who developed ASIA syndrome following HA injection after delayed inflammatory reaction (DIR) and emphasize the importance of the need for long-term monitoring after such the reaction. Lack of knowledge about ASIA can lead to delayed diagnosis and serious consequences for the patients. People with a history of immunization reactions, severe allergic reactions, individual predisposition to autoimmunity or family predisposition to autoimmunity and previous exposure to adjuvants require special attention and long-term follow-up. This applies primarily to cases of DIR after the using of bioimplants, especially with treatment resistance, as in our reported cases.

Evaluation and Management of Inflammatory Reactions to Vocal Fold Injection Laryngoplasty with Hyaluronic Acid

OBJECTIVES

Inflammatory reaction to vocal fold injection laryngoplasty with hyaluronic acid (HA) is a rare condition whose optimal management is not established. In this study, we aim to review the presentation of these reactions and outline an approach for evaluation and management.

METHODS

We performed a retrospective review of all patients at our institution who underwent vocal fold injection augmentation with HA during the period extending from August 2018 until October 2022. We then identified patients with postinjection inflammatory reaction and reviewed demographic data, indication for injection, amount of HA injected, setting of procedure, and symptoms. The types of complication, management plan, onset, and time to complete resolution were also recorded. A comprehensive literature search for similar complications was conducted for comparative analysis. Once the available data were aggregated with our institutional experience, we developed an algorithmic approach to manage this condition.

RESULTS

We identified 83 patients (124 vocal folds) who underwent vocal fold injection laryngoplasty with HA over a 4-year period. Four patients (4.8%) had a postprocedure inflammatory reaction (5.6% of all vocal folds). Of the four patients, three presented with dyspnea and stridor, while one presented with dysphonia, with onset of symptoms ranging from 24 to 48 hour postinjection. All patients were treated with corticosteroids. For comparative analysis, we identified 24 patients from the literature with reported inflammatory reactions to HA.

CONCLUSION

We suggest an algorithmic approach to managing laryngeal inflammation following HA injection. Familiarity with treatment for this rare complication is essential to avoid significant morbidity and achieve optimal outcomes.

LEVEL OF EVIDENCE: 4

No association found between late-onset inflammatory adverse events after soft tissue filler injections and the adaptive immune system

BACKGROUND

To date, it is unknown why some individuals develop late-onset inflammatory adverse events after treatment with fillers. These events may result from various factors, including an immunological response of the adaptive immune system.

OBJECTIVE

In a pilot study, we looked for evidence that is there a relation between late-onset inflammatory adverse events and the presence of immune cells surrounding the injected filler.

METHODS AND MATERIALS

We included 47 patients, of whom 20 experienced late-onset inflammatory adverse events to different fillers (inflammatory group) and 27 who did not (reference group). A biopsy was taken from the area of the adverse event. Hematoxylin-eosin staining and immunohistochemistry analysis with CD3 (T-cells) and CD68 (macrophages) on paraffin tissue sections was used to assess the biopsies.

RESULTS

Immune cells were found in biopsies obtained from 18 of 47 patients: Nine biopsies from the inflammation group and nine from the reference group. All these 18 cases showed CD68-positive immune cells. Virtually no CD3-positive immune cells were found.

CONCLUSION

Our results indicate that there is no T-cell activity in biopsies from areas with late-onset adverse events after filler injections. The macrophages found in the biopsies are probably not responsible for the inflammatory response.

Delayed complication of botulinum toxin and hyaluronic acid filler injections: A case report

BACKGROUND

Botulinum toxin and hyaluronic acid (HA) filler injections are popular minimally invasive cosmetic procedures owing to their convenience, efficiency, and durability; however, adverse reactions often occur.

MATERIALS AND METHODS

We describe the delayed hypersensitivity reaction that occurred after sequential injections of botulinum toxin and HA filler.

RESULTS

The histopathologic and dermatoscopic findings suggested a delayed hypersensitivity reaction with the formation of a dermal foreign body granuloma. The rash resolved 2 months following treatment with antihistamines and topical steroids cream.

CONCLUSION

We assume that local trauma during the blepharoplasty stimulated an immune response, which was the basis for this complication.

The Immunogenicity of Hyaluronic Fillers and Its Consequences

Hyaluronic acid (HA) is a glycosaminoglycan, a natural component of the extracellular matrix. The identical structure of the molecule in all living organisms is its main advantage, as it translates into the minimal probability of immunogenicity. Therefore, it is the closest to the ideal preparation used as a filler, due to its biocompatibility and stability at the site of implantation. This paper includes the discussion of the potential mechanisms of adverse immune reactions to HA along with the mechanisms of reaction following vaccinations against SARS-CoV-2. Based on the literature, we tried to systematize adverse immune reactions with systemic manifestations to HA. The occurrence of unpredictable reactions to hyaluronic acid indicates that they may not be treated as neutral or non-allergenic. The modifications of the chemical structure of HA, additives and individual tendencies in a patient may be the cause of unpredictable reactions, leading to serious health consequences. Preparations of unknown origin, poorly purified, or including bacterial DNA are particularly dangerous. Therefore, long-lasting follow-up of the patient and the selection of a preparation approved by the FDA or EMA are of high importance. Patients are often unaware of the consequences of cheaper procedures performed by persons without suitable knowledge with the use of unregistered products, so the public should be educated and legal regulations should be introduced.

Hypersensitivity reaction to Hyaluronic Acid Dermal filler following novel Coronavirus infection - a case report

The incidence of hypersensitivity reactions to hyaluronic acid dermal fillers is between 0.3 and 4.25%, mediated by T-lymphocytes. Flu-like illness can trigger immunogenic reactions at the site of filler placement. Cases of SARS-CoV-2 are significant and pose a possible risk of inducing hypersensitivity. This case report is of a delayed-type hypersensitivity after hyaluronic acid dermal filler treatment of the nose and subsequent infection with SARS-CoV-2. Risk factors for the development of such symptoms were identified as the presence of hyaluronic acid combined with flu-like illness and repeated treatment of one area. The case resolved without intervention. Clinicians should be mindful of the risk posed by the interaction of hyaluronic acid dermal filler with SARS-CoV-2 in light of the pandemic.

Hypersensitivity Caused by Cosmetic Injection: Systematic Review and Case Report

OBJECTIVE

Botulinum toxin injection, micro-needling injection, and filler injection are the most widely used non-surgical facial cosmetic treatments. Hypersensitivity reactions associated with injections have not received sufficient attention due to their low incidence rates. The authors tried to summarize the characteristics of the hypersensitivity caused by cosmetic injections and helped to improve the diagnosis and treatment.

METHODS

A comprehensive search of the PubMed database to September 2019 was performed. Articles were screened using predetermined inclusion and exclusion criteria. Data collected included patient characteristics, injection information (injected material, trade name, location of injection, symptoms of allergy, time of onset), diagnostic examination, treatment, and prognosis.

RESULTS

A total of 14 articles (57 patients) were included. There were 3 patients receiving botulinum toxin injection, 3 patients receiving micro-needling injection, and 46 patients receiving hyaluronic acid injection. Five patients were injected with collagen, polyacrylamide, paraffin, alkyl-imide or hyaluronidase, separately. The symptoms were redness, swelling, itching or induration at the injection site. The diagnosis and treatment methods vary greatly depending on the injection fillers. Removing the injected filler is the primary treatment.

CONCLUSION

Although hypersensitivity reaction is a relatively uncommon adverse event, more practice guidelines and research on diagnosis and treatment are demanded to help improve the outcomes.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the table of contents or the online instructions to authors www.springer.com/00266 .

Histopathologic reaction patterns to differentially cross-linked hyaluronic acid fillers: A retrospective case series

BACKGROUND

Hyaluronic acid filler reactions have been increasingly observed in recent years. Our study investigates whether the increased number of filler reactions observed since 2014 is associated with a specific histopathologic inflammatory pattern and type of filler.

METHODS

The institution's dermatopathology electronic database was retrospectively searched for histopathologic reactions to hyaluronic acid from January 2014 to December 2019. The age, sex, type of filler, procedure, location, and histopathologic patterns were recorded.

RESULTS

From 2014 to 2019, there were 15 cases of granulomatous reactions to hyaluronic acid filler. In 10 of these cases, there was a characteristic inflammatory pattern characterized by tightly cuffed palisades of histiocytes with varying numbers of eosinophils. Of the 11 cases in which the type of filler was known, all used Vycross technology, a novel manufacturing process in the production of hyaluronic acid filler.

CONCLUSION

A characteristic histopathologic pattern of discrete foci of tightly cuffed palisaded granulomas with eosinophils is associated with fillers manufactured using Vycross technology.

Late onset hypersensitivity reaction to hyaluronic acid dermal fillers manifesting as cutaneous and visceral angioedema

INTRODUCTION

Hyaluronic acid fillers are gaining popularity all across the globe. Although this aesthetic treatment is considered relatively safe, or that most unwanted effects are related to technical faults of the injections or infections, hypersensitivity reactions are being reported in acute or delayed forms. We herein describe an unusual case of hypersensitivity reaction to hyaluronic acid dermal fillers of 12-month latency, manifesting as cutaneous and visceral angioedema, and refractory to steroids, antihistamines and omalizumab.

AIM

We aim to raise awareness of delayed hypersensitivity reactions to hyaluronic acid fillers since patients often unaware due to the time lapse from the procedure.

PATIENTS/METHOD

A 47-year-old female, presenting with cutaneous and visceral angioedema 12 months after uneventful injection of hyaluronic acid-based dermal fillers.

RESULTS

Angioedema was refractory to systemic steroids, antihistamines and omalizumab. Symptoms resolved miraculously after dissolving the fillers with hyaluronidase.

CONCLUSION

In almost all previously described cases of late-onset response to hyaluronic acid dermal fillers, swelling was restricted to the treated area, was responsive to steroids or required no intervention at all. To our knowledge, this is an unusual case of hypersensitivity reaction to hyaluronic acid dermal fillers of 12-month latency, manifesting as refractory cutaneous and visceral angioedema.

The Correction of Facial Morphea Lesions by Hyaluronic Acid: A Case Series and Literature Review

INTRODUCTION

The aim of the study is to assess the long-term safety and efficacy of hyaluronic acid (HA) administration in correction of facial morphea lesions and to review the literature on the subject. Morphea is a chronic inflammatory disease of the connective tissue which may lead to serious deformations. The lesions located on the face particularly affect patients' quality of life and self-esteem; thus, there is a demand for safe and effective methods of treatment.

CASE PRESENTATION

The paper presents three female patients aged 16, 17 and 70 with facial morphea lesions who had HA preparation Juvéderm® Voluma or Volux, Vycross® technology, Allergan, injected. One of the patients had additionally fractional ablative CO2 laser (FAL) therapy.

DISCUSSION

The literature provides reports on successful use of HA, polymethylmethacrylate and poly-L-lactic acid for the correction of facial defects in localized scleroderma. HA is a natural component of the extracellular matrix and it therefore minimizes the probability of immunogenicity. The application technique also plays an important role. On the other hand, FAL therapy leads to the degradation of the abnormal collagen and the induction of normal collagen synthesis.

CONCLUSIONS

HA injection and combination of HA application with FAL are minimally invasive, effective and safe therapeutic options for patients suffering from morphea.

Immune profile of hyaluronic acid hydrogel polyethylene glycol crosslinked: An in vitro evaluation in human polymorphonuclear leukocytes

Neauvia hydrogel (N-Gel) is a hyaluronic acid-based dermal filler, cross-linked with polyethylene glycol. This filler contains sodium hyaluronate at different concentrations, poly(ethylene glycol) diglycidyl ether cross-linked, glycine, and l-prolyne. Assessing any effects of N-Gel on immunity and inflammation is of crucial importance. The aim of the study was to characterize the ability of N-Gel to modulate human polymorphonuclear leukocyte (PMN) functions, including migration, oxidative metabolism, and production of proinflammatory mediators. N-Gel was tested on isolated human PMN. Spontaneous and N-formylmethionyl-leucyl-phenylalanine (fMLP)-stimulated migration were examined using the Boyden Chamber technique, whereas the oxidative metabolism was assessed through spectrofluorometric measurement of reactive oxygen species (ROS) production under resting conditions and after stimulation with fMLP. Tumor necrosis factor (TNF)-α and interleukin (IL)-8 mRNA levels were measured by real-time PCR after stimulation with fMLP or Escherichia coli lipopolysaccharide. This study showed that N-Gel reduced fMLP-induced migration and ROS production without affecting these functions in resting cells. In addition, incubation of PMN with N-Gel effectively reduced both TNF-α and IL-8 mRNA levels. N-Gel modulates critical functions of human PMN such as migration and oxidative metabolism, indicating its potential as an anti-inflammatory agent.

A Systematic Review of the Literature of Delayed Inflammatory Reactions After Hyaluronic Acid Filler Injection to Estimate the Incidence of Delayed Type Hypersensitivity Reaction

BACKGROUND

Hyaluronic acid (HA) dermal filler injection is believed to be a safe procedure. However, with the increase in the number of performed procedures and indications, the number of product-related complications, especially delayed inflammatory reactions, has also increased. Delayed-type hypersensitivity (DTH) reaction is one of these delayed inflammatory reactions, which is preventable by performing a pretreatment skin test.

OBJECTIVES

The authors sought to find the incidence of delayed inflammatory reactions and DTH reaction after HA injection and to determine whether a pretreatment skin test is worthwhile to be performed.

METHODS

The authors conducted a systematic literature review of all the relevant prospective studies, retrospective studies, and case reports on delayed inflammatory reactions and DTH reaction after HA filler injection.

RESULTS

The incidence of delayed inflammatory reactions calculated from the prospective studies was 1.1% per year, and that of possible DTH reaction was 0.06% per year. Most retrospective studies estimated a percentage of delayed inflammatory reactions of less than 1% in 1 to 5.5 years. The incidence of DTH reaction would be lower than that. Among all the DTH cases reported, only about 5% of them were proven to be genuine DTH reactions.

CONCLUSIONS

The incidence of both delayed inflammatory reactions and DTH reaction is low. There is evidence that genuine DTH reactions caused by HA fillers approved by the Food and Drug Administration do exist. This adverse event can be prevented by performing a pretreatment skin test. However, the incidence of DTH reaction is so low that the pretreatment skin test is not mandatory if Food and Drug Administration-approved HA fillers are used.

LEVEL OF EVIDENCE: 4

Delayed-Onset Nodules to Differentially Crosslinked Hyaluronic Acids: Comparative Incidence and Risk Assessment

BACKGROUND

Robust and long-term data on true incidence of delayed-onset nodules and immune tolerance of hyaluronic acid (HA) fillers are lacking.

OBJECTIVE

To characterize the incidence of delayed nodules in Vycross (VYC) HA fillers compared with previously reported FDA and non-FDA data of all HA fillers.

METHODS AND MATERIALS

The incidence of delayed nodules in all patients who had received VYC fillers in a 12-month period was assessed through a retrospective chart review. Nodule incidence for currently approved nonanimal-stabilized hyaluronic acid (NASHA) fillers was assessed using the FDA Summary of Safety and Effectiveness Data.

RESULTS

Overall, 1,029 patients received 1,250 VYC filler treatments. Five patients developed delayed nodules to VOB, with an incidence of 1.0% per patient and 0.8% per syringe. No nodules were observed in patients who received VLR or VOL. All nodules were treated successfully using a combination of intralesional triamcinolone and hyaluronidase. Compared with other currently approved NASHA fillers, VOB is associated with a higher incidence of nodule formation.

CONCLUSION

The introduction of VYC HAs has introduced a new variable that may be changing the immune tolerance of these substances, resulting in a higher incidence of delayed nodules than previously expected.

Amniotic Allograft Implantation for Midface Aging Correction: A Retrospective Comparative Study with Platelet-Rich Plasma

Amniotic allografts are becoming more popular for use in soft tissue growth in many areas of medicine because of their immunoprivilege that allows them to proliferate into tissues without rejection by the host. Platelet-rich plasma (PRP) has crossed over from wide orthopedic uses to the aesthetic market for hair restoration and midface volume replacement, owing, in part, to the minimal risk associated with the procedure and the convenience of in-office application. In addition, growth factors provided by PRP help stimulate collagen synthesis in the aging face. However, the potential recruitment of the patient’s own mesenchymal stem cells to the PRP injection site would produce the most favorable and sustained aesthetic outcome. With the advancement of amniotic allograft procedures, the introduction of live mesenchymal cells of the amniotic membrane into the aging midface could be performed in-office similarly to the PRP treatment. This retrospective chart review compares aspects of the amniotic allograft procedure (office time, level of comfort, and downtime) with the aesthetic results of injection into the midface of those undergoing PRP therapy. Analysis of the changes to midface volume, specifically the Ogee curve, observed in the chronological progression of photographs illustrates aesthetic improvements in both PRP and amnion allograft treatment groups, with changes in the facial grading scale. Less patient downtime and slightly more rapid improvements were noted in the amnion group in comparison with the PRP treatment participants.

Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Cetuximab associated dermal filler reaction

A 52-year-old male patient with hyaluronic acid-based dermal fillers injected in his cheeks was diagnosed with glossotonsillary malignancy, and managed with concurrent cetuximab (epidermal growth factor receptor inhibitor) and radiation therapy. He developed significant inflammation around the dermal filler sites after first cycle of cetuximab which improved with dissolution of the dermal fillers with hyaluronidase. This suggests that cetuximab can lead to inflammation around the dermal filler sites, which can be treated with dissolution of the filler.

Delayed hypersensitivity reaction to hyaluronic acid dermal filler following influenza-like illness

Background: Delayed reactions after facial hyaluronic acid injection are relatively rare complications. Their cause may be infectious or immune-mediated in origin, and their outbreak can be triggered, for example, by an influenza-like illness. Objective: To describe potential adverse event of influenza like illness following dermal filler injection. Methods: We report fourteen unusual cases of delayed hypersensitivity reaction to several brands of hyaluronic acid dermal filler following influenza like illness. Results: Increasing evidence implicates influenza infection in the pathogenesis of late onset filler reaction. Conclusion: Although there is a low risk of late onset adverse reaction with hyaluronic acid fillers, injecting physicians must be aware of the possible filler reaction following the influenza infection.

Complication Management following Rejuvenation Procedures with Hyaluronic Acid Fillers-an Algorithm-based Approach

BACKGROUND

Hyaluronic acid is an ideal facial filler, however, although established as both safe and effective, complications do occur. Treatment recommendations that combine both expert opinions and clinical trial data are currently lacking, partly due to difficulties with diagnoses, nonspecific diagnostic investigations, and certain disorders presenting with similar symptoms, thereby confounding diagnosis and treatment.

METHODS

The purpose of this article was to provide the aesthetic clinician with practical recommendations regarding complication diagnosis arising as a consequence of hyaluronic acid filler rejuvenation treatment. It also provides recommendations for their management using step-wise treatment algorithms that are based on published expert opinions, as well as the author's clinical experience.

RESULTS

Algorithms are provided for the most common categories of complication associated with hyaluronic acid filler treatment, that is, skin discoloration, edema, nodules, infection, and vascular compromise.

CONCLUSIONS

These guidelines are not intended to be complete or exhaustive but may prove informative for aesthetic clinicians who are responsible for treating patients with hyaluronic acid fillers. It may help to guide them on recognizing potential complications and it provides clear guidance on optimum treatment pathways.

Beyond photoaging: additional factors involved in the process of skin aging

Studies assessing the impact of extrinsic factors on skin aging have increased during the last with the increase in life expectancy. Although most of the studies are about the sun radiation impact, many factors should be considered in elderly people, beyond environmental conditions. Lifestyle factors, like diet, sleeping, smoking, should be analyzed carefully, as common age-related conditions (menopause, diabetes, pulmonary diseases, etc.). All these factors could accelerate the natural decline of skin structure and functions, possibly affecting the responses to treatments and drugs. This review demonstrates that growing evidence regarding environmental factors that are associated with lifestyle and comorbidities deserve greater attention from researchers and dermatologists and may require new approaches in the management of skin aging.

An Effective Translation: The Development of Hyaluronan-Based Medical Products From the Physicochemical, and Preclinical Aspects

This review shows the steps toward material selection focalized on the design and development of medical devices based on hyaluronan (HA). The selection is based on chemical and mechanical properties, biocompatibility, sterilization, safety, and scale-up costs. These facts play a vital role in the industrialization process. Approved medical devices containing-HA are illustrated to identify key parameters. The first part of this work involves the steps toward a complete characterization of chemical and mechanical aspects, reproducibility of the processes and scale up. In a second stage, we aimed to describe the preclinical in vitro and in vivo assays and selected examples of clinical trials. Furthermore, it is important to keep in mind the regulatory affairs during the research and development (R&D) using standardization (ISO standards) to achieve the main goal, which is the functionality and safety of the final device. To keep reproducible experimental data to prepare an efficient master file for the device, based on quality and recorded manufacturing data, and a rigorous R&D process may help toward clinical translation. A strong debate is still going on because the denominated basic research in HA field does not pay attention to the purity and quality of the raw materials used during the development. So that, to achieve the next generation of devices is needed to overcome the limitations of state of art in terms of efficacy, biodegradability, and non-toxicity.

Late-Onset Inflammatory Response to Hyaluronic Acid Dermal Fillers

Objective:

Even though injectable hyaluronic acid (HA)–based fillers are considered safe, rare complications, such as late-onset inflammatory reactions have been reported. Possible causes and effective treatments have not been formally described, so this work aims to discuss these and offer a formal protocol for treatment.

Methods:

This article presents 5 clinical cases of late-onset inflammatory response occurring at least 3 months after uneventful injection of HA dermal filler.

Results:

Inflammation appeared spontaneously, usually 4–5 months after the last injection, but in 1 patient, almost 14 months later. One patient was injected at the same time with fillers manufactured by 2 different technologies. In this case, all areas treated with the same filler showed diffuse swelling of inflammatory nature, whereas the lips, treated with the second filler brand, remained unaffected. Four patients reported a flu-like illness or gastrointestinal upset a few days before the onset of dermal filler inflammation.

Conclusion:

Late-onset inflammatory reactions to HA fillers may be self-limiting but are easily and rapidly treatable with oral steroids, and with hyaluronidase in the case of lumps. It is likely these reactions are due to a Type IV delayed hypersensitivity response. Delayed inflammation associated with HA fillers is nonbrand specific. However, the case where 2 different brands were injected during the same session, but only 1 brand triggered a hypersensitivity reaction, suggests that the technology used in the manufacturing process, and the subsequent differing products of degradation, may have an influence on potential allergic reactions to HA fillers.

Immunological reaction after facial hyaluronic acid injection

We report two rare cases of inflammatory reactions with multiple subcutaneous facial painful collections after Hyaluronic acid injections, expose their management and discuss aetiologic hypothesis. Due to unfavourable evolution despite antibiotic treatment, surgical drainage was performed. Immune-mediated delayed hypersensitivity reactions were the most probable cause.

Consensus statement on prevention and management of adverse effects following rejuvenation procedures with hyaluronic acid-based fillers

Facial fillers play an important role in the correction of facial changes associated with ageing. They offer quick treatments in the outpatient setting with minimal subsequent downtime that provide predictable, natural-looking, long-lasting results. Adverse reactions after hyaluronic acid injections tend to be mild or moderate and rather temporary. However, as with all injected or implanted biomaterials, severe adverse events can occur and patients must be fully informed of potential risks prior to undergoing treatment. A panel of experts from Germany (D), Austria (A) and Switzerland (CH) developed recommendations, and this study provides the 'DACH Consensus Recommendations' from this group specifically on the use of hyaluronic acid fillers. The aim is to help clinicians recognize potential risks and to provide guidance on how best to treat adverse events if they arise. Contraindications to hyaluronic acid fillers are also detailed, and ways to prevent adverse events occurring are discussed. Hyaluronic acid-based products are claimed to be very close to an ideal tissue augmentation agent; nevertheless, profound medical, anatomical and product knowledge are of paramount importance to minimize the occurrence of adverse reactions.

Hyaluronic acid fillers with cohesive polydensified matrix for soft-tissue augmentation and rejuvenation: a literature review

Background

Cohesive monophasic polydensified fillers show unique viscoelastic properties and variable density of hyaluronic acid, allowing for a homogeneous tissue integration and distribution of the material.

Objective

The aim of this paper was to review the clinical data regarding the performance, tolerability, and safety of the Belotero^® fillers for soft-tissue augmentation and rejuvenation.

Methods

A literature search was performed up until May 31, 2015 to identify all relevant articles on Belotero^® fillers (Basic/Balance, Hydro, Soft, Intense, Volume) and equivalent products (Esthélis^®, Mesolis^®, Fortélis^®, Modélis^®).

Results

This comprehensive review included 26 papers. Findings from three randomized controlled trials showed a greater reduction in nasolabial fold severity with Belotero^® Basic/Balance than with collagen (at 8, 12, 16, and 24 weeks, n=118) and Restylane^® (at 4 weeks, n=40), and higher patient satisfaction with Belotero^® Intense than with Perlane^® (at 2 weeks, n=20). With Belotero^® Basic/Balance, an improvement of at least 1 point on the severity scale can be expected in ~80% of patients 1–6 months after injection, with an effect still visible at 8–12 months. Positive findings were also reported with Belotero^® Volume (no reduction in hyaluronic acid volume at 12 months, as demonstrated by magnetic resonance imaging), Soft (improvement in the esthetic outcomes when used in a sequential approach), and Hydro (improvement in skin appearance in all patients). The most common adverse effects were mild-to-moderate erythema, edema, and hematoma, most of which were temporary. There were no reports of Tyndall effect, nodules, granulomas, or tissue necrosis.

Conclusion

Clinical evidence indicates sustainable esthetic effects, good safety profile, and long-term tolerability of the Belotero^® fillers, particularly Belotero^® Basic/Balance and Intense.