Hyaluronic acid skin fillers: adverse reactions and skin testing

Dermatologic Complications Following Cosmetic and Reconstructive Plastic Surgery: A Systematic Review of the Literature

PURPOSE

Plastic surgery procedures, including minimally invasive cosmetic procedures, continue to grow in popularity. Although dermatologic complications following plastic surgery procedures are rare, the authors have encountered several of these complications in their practice, including herpes simplex virus (HSV-1) and varicella zoster virus (VZV) infections, pyoderma gangrenosum (PG), contact dermatitis, and suture hypersensitivity. These cases prompted a systematic literature review of dermatologic complications following plastic surgery procedures.

METHODS

The authors conducted a systematic review of PubMed, MEDLINE, EMBASE, Scopus, Web of Science, and the Cochrane Library to identify relevant articles published from 1975 to 2021. Articles were independently reviewed by the authors to determine whether studies met inclusion criteria.

RESULTS

The majority of articles that met inclusion criteria represented level V evidence. The most robust evidence in the literature was for PG, for which there were 63 total studies. Pyoderma gangrenosum was most frequently reported following breast surgery (85.1%), while HSV-1 infections were frequently seen following minimally invasive procedures (84.6%). VZV reactivation was reported after a range of interventions, including pedicled flap surgeries and laser treatments. Other complications, such as suture hypersensitivity, were less frequently reported in the literature, usually as isolated case reports.

CONCLUSIONS

Dermatologic complications represent a rare but serious concern following plastic surgery procedures. While most dermatologic complications resolve with appropriate treatment, sequelae of these conditions can be devastating to the patient's overall outcome. Plastic surgeons performing procedures at a high risk of these complications should recognize the diagnostic criteria to facilitate appropriate treatment.

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 .

The Aetiopathogenesis of Late Inflammatory Reactions (LIRs) After Soft Tissue Filler Use: A Systematic Review of the Literature

Background

Late inflammatory reactions (LIRs) are the most challenging complications after filler use. The immune system plays a prominent role in its etiology, albeit to an unknown extent. Bacterial contamination in situ has been hypothesized to be causative for LIRs. How this relates to the immunological processes involved is unknown. This article aims to provide an overview of immunological and bacterial factors involved in development of LIRs.

Methods

We undertook a systematic literature review focused on immunological factors and microbiota in relation to LIRs after filler use. This systematic review was performed in accordance with the PRISMA guidelines. PubMed, EMBASE and the Cochrane databases were searched from inception up to August 2019. Included studies were assessed for the following variables: subject characteristics, number of patients, primary indication for filler injection, implant type/amount and injection site, type of complication, follow-up or injection duration, study methods, type of antibiotics or medical therapies and outcomes related to microbiota and immunological factors.

Results

Data on immunological factors and bacterial contamination were retrieved from 21 included studies. Notably, the presence of histocytes, giant cells and Staphylococcus epidermidis within biopsies were often associated with LIRs.

Conclusion

This review provides a clear overview of the immunological factors associated with LIRs and provides a hypothetical immunological model for development of the disease. Furthermore, an overview of bacterial contamination and associations with LIRs has been provided. Follow-up research may result in clinical recommendations to prevent LIRs.

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..

Supplementary Information

The online version contains supplementary material available at 10.1007/s00266-021-02306-3.

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.

Immediate nor Delayed Type Hypersensitivity Plays a Role in Late Inflammatory Reactions After Hyaluronic Acid Filler Injections

Purpose

The exact etiology of late inflammatory reactions (LIRs) to hyaluronic acid (HA) fillers is currently unknown. Some argue that these result from a hypersensitivity reaction, although evidence to support this is very scarce. Most reports on such reactions are not substantiated by positive skin tests. The purpose of our study was to determine whether immediate or delayed type hypersensitivity reaction follows hyaluronic acid (HA) filler injections.

Patients and Methods

Twelve patients were referred for general allergic screening (patch tests), as well as specific intradermal testing (injection of 0.1cc boluses) on the medial upper arm with a selection of several currently available hyaluronic acid (HA) fillers on the market. A positive allergic reaction was defined as erythema, firmness or swelling.

Results

During the 4 month follow-up, no reactions to any of the tested HA fillers were reported. No correlation was found between results from the general allergic screening and a history with LIRs to HA fillers.

Conclusion

The results suggest that neither type I nor type IV hypersensitivity plays a role in late inflammatory reactions (LIRs) to hyaluronic acid (HA) fillers.

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The art of prevention: COVID-19 vaccine preparedness for the dermatologist

As COVID-19 vaccinations begin, dermatologists must be aware of the cutaneous adverse events reported in the clinical trials, including injection site and hypersensitivity reactions, and emerging evidence of dermal filler injection reactions after vaccination. The filler reaction may represent the development of a delayed-type hypersensitivity in the setting of another immunologic trigger (i.e., the vaccine). After conducting a literature review of similar reactions, their pathophysiology, and management, we present a set of timely clinical considerations for counseling, prevention, and management of possible cutaneous sequelae of the COVID-19 vaccine. We encourage documentation of vaccine-related reactions to aid the safety data collection in the Vaccine Adverse Event Reporting System and the American Academy of Dermatology COVID-19 Registry.

Physicians' and patients' self-perceptions of hyaluronic acid-based facial volumization: Are they compatible?

BACKGROUND

Facial filling based on hyaluronic acid (HA) is an esthetic procedure that is widely performed worldwide.

METHODOLOGY

Fifty patients underwent facial filling based on HA, and 10 board-certified dermatologists evaluated clinical photographs before and after the procedure and completed a questionnaire to provide information about the procedure.

RESULTS

All doctors and 96% of patients were agreed about the pre- and postprocedural photographs. Physicians were more aware of the possibility of frequent pain and erythema. Both groups showed agreement in their responses on the following topics: the possibility of hematoma and edema, a lack of secretion, improvement in patients' self-confidence, recognition of the procedure by third parties, and knowledge of the procedure by the dermatologists themselves. However, physicians tend to overestimate the possibility of erythema, pain, and edema; they also tend to minimize the duration and discomfort of postprocedural edema and the risk of third parties noticing patients' HA filling and how much it bothers patients when third parties do notice.

CONCLUSION

Doctors and patients disagree on some questions about what actually happens and what is supposed to happen in facial filling procedures based on HA.

Lymphangioma Formation Following Hyaluronic Acid Injection for Lip Augmentation

Administration of hyaluronic acid (HA) filler for aesthetic lip augmentation is a routine and common procedure with a low rate of adverse reactions. This case report documents an extremely rare complication of lip augmentation with HA leading to the development of lymphangiomas.

Lymphangiomas are uncommon hamartomas of the lymphatic system. Although usually congenital, they can be acquired due to trauma, inflammation, or lymphatic blockage. They may be in the deep or superficial tissues, with superficial forms being either lymphangioma circumscriptum or acquired lymphangioma, also referred to as lymphangiectasia. Acquired lymphangiomas are typically formed by blockage of lymphatic drainage leading to dilation of the lymphatic channels. The diagnosis in our case report is acquired lymphangioma.

A 27-year-old female presented with a two-year history of linear swellings in her upper lip. These lumps followed the line where HA filler had been injected four years earlier. Hyaluronidase had previously been used unsuccessfully to remove these lumps. The patient was treated with surgery to excise the lesions. Five masses were excised, and histopathological analysis displayed the presence of variably ectatic lacunae, lined by cells with CD34 expression, a lymph-vascular-endothelial marker. There were also scattered macrophages with CD68 expression in the interstices. These are typical features of a lymphangioma. The patient was satisfied with the excellent aesthetic and functional outcome.

To our knowledge this is the first case of a lymphangioma following HA lip augmentation. Although rare, this complication can have aesthetic implications for the patient which may require further treatment or surgery to correct.

Majocchi's granuloma caused by Trichophyton rubrum after facial injection with hyaluronic acid: A case report

BACKGROUND

Facial cosmetic procedures become popular for people with a desire to have a younger appearance, and cosmetic technology has developed rapidly over the past several decades. However, increasing complications related to cosmetic injections have been reported, and infection is one of the most serious problems and can cause anxiety and facial injury. We here report a case of Majocchi's granuloma (MG) caused by Trichophyton rubrum after facial injection of hyaluronic acid.

CASE SUMMARY

A 37-year-old woman presented to our hospital with a history of red papules, nodules, and abscesses on her left zygomatic arch for 2 mo. She had received a cosmetic injection of hyaluronic acid on the left side of her face prior to the appearance of the lesions. MG caused by Trichophyton rubrum after facial injection of hyaluronic acid was diagnosed based on morphology and molecular biological identification. In vitro antifungal susceptibility testing was conducted according to the Clinical and Laboratory Standards Institute M38-A2 method. Minimal inhibitory concentrations were used to evaluate the antifungal susceptibility. The antifungal agents and their minimal inhibitory concentrations for the strain were terbinafine (< 0.5 μg/mL), itraconazole (0.06 μg/mL), amphotericin B (0.25 μg/mL), fluconazole (32 μg/mL), voriconazole (0.125 μg/mL), posaconazole (0.125 μg/mL), and isavuconazole (0.06 μg/mL). We initially administered 250 mg/d oral terbinafine for 2 mo, but the patient still had painful papules, nodules and abscesses on her face. Then, we adjusted the treatment to itraconazole 400 mg/d for 8 wk based on the in vitro antifungal susceptibility testing results. The skin lesions improved significantly, and there was no recurrence during follow-up.

CONCLUSION

This case revealed that facial injection of hyaluronic acid may cause serious MG. Antifungal susceptibility testing should be considered in the treatment of MG caused by Trichophyton rubrum.

Human Histology and Persistence of Various Injectable Filler Substances for Soft Tissue Augmentation

An increasing number of soft tissue filler substances have been introduced to the beauty market outside the U.S. which lackexperimental and clinical data in support of their claim. Ten commercially available filler substances were examined for biocompatibility and durability: 0.1 cc of each substance was injected deep intradermally into the volar forearm of one of the authors and observed for clinical reaction and permanence. At 1, 3, 6, and 9 months the test sites were excised, histologically examined, and graded according to foreign body reactions classification. Collagen (Zyplast) was phagocytosed at 6 months and hyaluronic acid (Restylane) at 9 months. PMMA microspheres (Artecoll) had encapsulated with connective tissue, macrophages, and sporadic giant cells. Silicone oil (PMS 350) was clinically inconspicuous but dissipated into the tissue, causing a chronic foreign body reaction. Polylactic acid microspheres (New-Fill) induced a mild inflammatory response and had disappeared clinically at 4 months. Dextran microspheres (Reviderm intra) induced a pronounced foreign body reaction and had disappeared at 6 months. Polymethylacrylate particles (Dermalive) induced the lowest cellular reaction but had disappeared clinically at 6 months. Polyacrylamide (Aquamid) was well tolerated and remained palpable to a lessening degree over the entire testing period. Histologically, it dissipated more slowly and was kept in place through fine fibrous capsules. Polyvinylhydroxide microspheres suspended in acrylamide (Evolution) were well tolerated, slowly diminishing over 9 months. Calcium hydroxylapatite microspheres (Radiance FN) induced almost no foreign body reaction but were absorbed by the skin at 12 months.Host defense mechanisms react differently to the various filler materials, but all substances- resorbable or nonresorbable-appeared to be clinically and histologically safe, although all exhibit undesirable side effects. Since the mechanism of late inflammation or granuloma formation is still unknown, early histological findings are not useful in predicting possible late reactions to filler substances.

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

First Aldol Cross-Linked Hyaluronic Acid Hydrogel: Fast and Hydrolytically Stable Hydrogel with Tissue Adhesive Properties

Currently, there are limited approaches to tailor 3D scaffolds cross-linked with a stable covalent C-C bond that does not require any catalysts or initiators. We present here the first hydrogels employing aldol condensation chemistry that exhibit exceptional physicochemical properties. We investigated the aldol-cross-linking chemistry using two types of aldehyde-modified hyaluronic acid (HA) derivatives, namely, an enolizable HA-aldehyde (HA-Eal) and a non-enolizable HA-aldehyde (HA-Nal). Hydrogels formed using HA-Eal demonstrate inferior cross-linking efficiency (due to intramolecular loop formation), when compared with hydrogels formed by mixing HA-Eal and HA-NaI leading to a cross-aldol product. The change in mechanical properties as a result of cross-linking at different pH values is determined using rheological measurements and is interpreted in terms of molecular weight between cross-links (M_c). The novel HA cross-aldol hydrogel demonstrate excellent hydrolytic stability and favorable mechanical properties but allow hyaluronidase-mediated enzymatic degradation. Interestingly, residual aldehyde functionality within the aldol product rendered the tissue-adhesive properties by bonding two bone tissues. The aldehyde functionality also facilitated facile post-synthetic modifications with nucleophilic reagents. Finally, we demonstrate that the novel hydrogel is biocompatible with encapsulated stem cells that show a linear rate of expansion in our 3-6 days of study.

Evaluating the Safety and Efficacy of a Highly Viscous 33-mg/mL Hyaluronic Acid Volumizing Filler in the Treatment of Facial Wrinkles: An Open-Labeled, Clinical Trials

Background:

The 33-mg/mL hyaluronic acid (HA) formulation is a highly concentrated, cross-linked, cohesive, smooth, and completely reversible volumizing filler approved by Conformité Européene. For the first time, we aimed to evaluate the long-term efficacy and safety of the 33- mg/mL HA filler for soft tissue augmentation in the treatment of facial wrinkles.

Materials and Methods:

After optimal wrinkle correction was achieved in the patients undergoing treatment by injecting the 33-mg/mL HA filler at the injection site plus one touch-up at a 2-week interval, the safety and efficacy of the filler were assessed on the 5-point Facial Volume Loss Scale through the 1-year study period. Patients were evaluated daily for 14 days and after 6 and 12 months post-treatment.

Results:

A total of 86 subjects were treated. The mean wrinkle scores of the patients were 3.95+0.79 (range of 3-5) before treatment, 2.3+0.94 (range 1-5) six months after treatment, and 2.93+1.29 (range of 1-5) one year after treatment. Clinically significant mean wrinkle correction (P=0.001) was still evident at>12 months of treatment through 33-mg/ mL HA formulation. A clinically significant correction at>12 months after treatment was maintained by 79% of patients. Nodule formation and swelling were more frequent when the 33- mg/mL HA filler was used compared with the use of less concentrated HA fillers. One patient developed angioedema-like swelling and induration last few months.

Conclusion:

The 33-mg/ mL HA filler can provide long-term correction lasting for one year or more. Adverse effects, especially swelling and nodule formation were more common in this filler compared with less concentrated HA fillers. The side effects were correlated with the volume of the injected filler. We recommend using this concentration with low volume or combining high volume with lower concentration.

Full-face augmentation using Tissuefill mixed with platelet-rich plasma: "Q.O.Fill"

BACKGROUND

Hyaluronic acid fillers have become popular soft tissue filler augmentation agents over the past several years. Q.O.Fill (JW Pharmaceutical Co., Ltd., Seoul, Korea) is a newly developed soft tissue augmentation agent using Tissuefill (hyaluronic acid derivatives) mixed with platelet-rich plasma (PRP). The purposes of this study were to describe the Q.O.Fill method and evaluate the outcome of face augmentation.

METHODS

A retrospective chart review was performed over a 2-year period. Seventy-five Asian participants with a mean age of 43.5 years were enrolled in the study. Mean total injection volume (baseline and touch-up) per participant was 8.9 mL. All participants underwent injection of Tissuefill mixed with PRP, Q.O.Fill. The results were evaluated using photographs and according to patients' satisfaction.

RESULTS

Six months after the last injection, 100% of participants had improvement. At month 6, 97.3% of participants remained least improved over the baseline, and 90.7% felt much better or a little better until 2 years after the injection. The incidence of complications was low.

CONCLUSIONS

The study showed that Q.O.Fill injection resulted in a very good aesthetic outcome and few adverse events. We believe that a facial augmentation with Tissuefill mixed with PRP is a safe and effective treatment method.

Microneedles containing cross-linked hyaluronic acid particulates for control of degradation and swelling behaviour after administration into skin

Microneedles (MN) containing cross-linked hyaluronic acid (X-linked HA) particulates were prepared to control the degradation and swelling behaviour after transdermal drug delivery. The X-linked HA particulates were prepared by cross-linking HA chains and then passing the particulates through a sieve. Then, microneedles were prepared by micromolding method. The rheological properties of X-linked HA were studied. The penetration success rate, mechanical failure and dissolution rate of microneedles containing only hyaluronic acid (HA MN) and microneedles containing X-linked HA were compared. The delivery of fluorescein into the skin with X-linked HA MN was also observed using a confocal microscope. The size of the pulverised particulates in water ranged between 29 and 82 μm in diameter. The HA MN and X-linked HA MN were 270 μm in length. X-linked HA MN with fluorescein was inserted to a depth of 90% of the microneedle length successfully. There was no decrease in the penetration success rate for MN with up to 20% content of X-linked HA particulates. X-linked HA MN with up to 20% of particulate content did not change the dissolution time. Delay in degradation of HA, sustained drug release, and swelling behaviour of the skin layer can be obtained by X-linked HA MN.

Evaluation of MC3T3 Cells Proliferation and Drug Release Study from Sodium Hyaluronate-1,4-butanediol Diglycidyl Ether Patterned Gel

A pattern gel has been fabricated using sodium hyaluronate (HA) and 1,4-butanediol diglycidyl ether (BDDGE) through the micro-molding technique. The cellular behavior of osteoblast cells (MC3T3) in the presence and absence of dimethyloxalylglycine (DMOG) and sodium borate (NaB) in the pattern gel (HA-BDDGE) has been evaluated for its potential application in bone regeneration. The Fourier transform infrared spectroscopy (FTIR), 13C-nuclear magnetic resonance spectroscopy (13C NMR), and thermogravimetric analysis (TGA) results implied the crosslinking reaction between HA and BDDGE. The scanning electron microscopy (SEM) analysis confirmed the formation of pattern on the surface of HA-BDDGE. The gel property of the crosslinked HA-BDDGE has been investigated by swelling study in distilled water at 37 °C. The HA-BDDGE gel releases DMOG in a controlled way for up to seven days in water at 37 °C. The synthesized gel is biocompatible and the bolus drug delivery results indicated that the DMOG containing patterned gel demonstrates a better cell migration ability on the surface than NaB. For local delivery, the pattern gel with 300 µM NaB or 300 µM DMOG induced cell clusters formation, and the gel with 150 µM NaB/DMOG showed high cell proliferation capability only. The vital role of NaB for bone regeneration has been endorsed from the formation of cell clusters in presence of NaB in the media. The in vitro results indicated that the pattern gel showed angiogenic and osteogenic responses with good ALP activity and enhanced HIF-1α, and Runx2 levels in the presence of DMOG and NaB in MC3T3 cells. Hence, the HA-BDDGE gel could be used in bone regeneration application.

The use of mastoid fascia for dorsal nasal augmentation

Background and aim

Dorsal augmentation of the nose is needed after trauma, rhinoplasty or for ethnic reasons. Alloplastic or autogenous materials may be used. In this paper, postauricular mastoid fascia was used for dorsal nasal augmentation.

Methods

This study included ten patients who underwent dorsal nasal augmentation. Fascia over mastoid area was taken in all cases and was fixed with Steri-Strips and external nasal splints.

Results

All patients were female except one case. Five patients had the operation because of ethnic causes and five patients did the operation due to post traumatic deformity. Donor sites healed uneventfully. Digital photography was taken to assess the grafts and follow up was extended up to 9 months.

Conclusions

Mastoid fascia is a reliable method and its donor site is hidden. In addition, it can be a potential site for conchal graft if needed.

Hyaluronic acid-supported combination of water insoluble immunostimulatory compounds for anti-cancer immunotherapy

A novel powder-form combination adjuvant system containing two immunostimulatory compounds was firstly developed and evaluated as a therapeutic intervention for cancer immunotherapy. With the help of hyaluronic acid (HA), water insoluble monophosphoryl lipid A (MPL), QS21 and imiquimod (R837), could be easily dispersed in aqueous solution and lyophilized as powder-form, which have an advantage in room-temperature storage stability compared with those conventional liquid formulation that requires cold storage. Two kinds of HA-based combination vaccine adjuvants (HA/MPL/QS21, HMQ and HA/MPL/R837, HMR) contributed to the increase of both humoral and cellular immunity, which is very important for efficient cancer immunotherapy. Through the challenge experiments in EG7-OVA (mouse lymphoma-expressing OVA) tumor-bearing mice model, we found out that the immunostimulatory effects of HMQ and HMR were successful in the inhibition of tumor proliferation. Taken together, both HA-based powder-form combination adjuvant systems are expected to be used as potent prophylactic and therapeutic cancer vaccine.

Delayed immunologic complications due to injectable fillers by unlicensed practitioners: our experiences and a review of the literature

For a number of years, there have been unauthorized practitioners who have been illegally injecting substances. In this series of cases, delayed type hypersensitivity reactions occurred after having unknown material fillers injected by unlicensed practitioners. When injecting an unknown material, there can be a severe immune reaction due to the unknown number of antigens in the material, and therefore may act as a much stronger superantigen than conventional filler materials. It appears that the adverse effects in these cases are more severe and have tendency to break out after a longer period of time in comparison with those caused by approved fillers, likely due to operative technique and use of unverified materials. It is important to recognize the danger of such illegal procedures and to increase awareness of the public, as this has evolved into a significant public health issue.

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

Hyaluronic acid (HA) fillers in cosmetic medicine have been considered relatively safe, though fillers used in European countries and throughout the world are not necessarily approved by the Food and Drug Administration. As their use continues to expand worldwide, physicians in a wide range of medical specialties are authorized to perform HA injections, including general medicine practitioners and even dentists. An increasing number of reports have appeared regarding side effects to these products. It is now known that reactions to Hyaluronic acid are related not only to technical faults of the injections, but also to immune responses, including delayed hypersensitivity and granulomatous reactions. Herein, we describe five cases treated by a variety of treatment modalities, all with delayed reactions to different brands of hyaluronic acid fillers. As there is currently no standardization of treatment options of adverse effects, these cases accentuate the debate regarding the approach to the individual patient and the possible need for pre-testing in patients with an atopic tendency.

New-generation filler based on cross-linked carboxymethylcellulose: study of 350 patients with 3-year follow-up

Purpose

In recent years there has been a growing interest in nonsurgical procedures for facial rejuvenation. Hyaluronic acid is currently the most widely used dermal filler for the treatment of facial wrinkles. However, new products with interesting features are being introduced into the market. Cross-linked carboxymethylcellulose is one of these and represents a new alternative for the correction of wrinkles and facial defects.

Patients and methods

The retrospective, multicenter, open-label study on nasolabial folds reported here was carried out between January 2010 and April 2014 on 350 subjects between 22 and 67 years of age for a 36-month follow-up period in order to consistently and extensively assess the safety and performance of this treatment.

Results

The study revealed effective and durable correction of nasolabial wrinkles for periods of 9–12 months. Product reapplication over a 36-month period did not lead to an increase in adverse effects, which always remained rare and of little clinical significance, usually consisting of bruising and redness.

Conclusion

Cross-linked carboxymethyl cellulose has been shown to be a safe and effective alternative to the resorbable products currently on the market.

New adipose tissue formation by human adipose-derived stem cells with hyaluronic acid gel in immunodeficient mice

BACKGROUND

Currently available injectable fillers have demonstrated limited durability. This report proposes the in vitro culture of human adipose-derived stem cells (hASCs) on hyaluronic acid (HA) gel for in vivo growth of de novo adipose tissue.

METHODS

For in vitro studies, hASCs were isolated from human adipose tissue and were confirmed by multi-lineage differentiation and flow cytometry. hASCs were cultured on HA gel. The effectiveness of cell attachment and proliferation on HA gel was surveyed by inverted light microscopy. For in vivo studies, HA gel containing hASCs, hASCs without HA gel, HA gel alone were allocated and subcutaneously injected into the subcutaneous pocket in the back of nude mice (n=6) in each group. At eight weeks post-injection, the implants were harvested for histological examination by hematoxylin and eosin (H&E) stain, Oil-Red O stain and immunohistochemical staining. The human-specific Alu gene was examined.

RESULTS

hASCs were well attachment and proliferation on the HA gel. In vivo grafts showed well-organized new adipose tissue on the HA gel by histologic examination and Oil-Red O stain. Analysis of neo-adipose tissues by PCR revealed the presence of the Alu gene. This study demonstrated not only the successful culture of hASCs on HA gel, but also their full proliferation and differentiation into adipose tissue.

CONCLUSIONS

The efficacy of injected filler could be permanent since the reduction of the volume of the HA gel after bioabsorption could be replaced by new adipose tissue generated by hASCs. This is a promising approach for developing long lasting soft tissue filler.

Biological evaluation of micro-patterned hyaluronic acid hydrogel for bone tissue engineering

Design of micro-patterning of hydrogel is of critical importance in both understanding cellular behaviors and mimicking controlled microenvironments and architectures of diverse well-organized tissues. After micro-patterning of hyaluronic acid (HA) hydrogel on a poly(dimethyl siloxane) substrate, its physical and biological properties have been compared with those of a non-patterned hydrogel for its possible applications in bone tissue engineering. The micro-patterned morphologies of HA hydrogel in both swollen and dehydrated forms have been observed with light microscope and scanning electron microscope, respectively, before and after in vitro cell culture. When MC3T3 bone cells were in vitro cultured on both HA hydrogels, the micro-patterned one shows excellence in cell proliferation and lining for 7 days along the micro-pattern paths over those of the non-patterned one, which have shown less cell-adhesiveness. The cytotoxicity of the micro-patterned HA hydrogels was in vitro evaluated by the assays of MTT, BrdU and Neutral red. The viability and morphology of MC3T3 cells on both HA hydrogels were observed with a fluorescence microscope by the live & dead assay, where their viability was confirmed by staining of F-actin development. The results of their H&E staining showed that both micro-patterned and non-patterned hydrogels induced development of tissue regeneration as observed by cell attachment, proliferation, and survivability, but the micro-patterned one induced distinctive patterning of both better initial cells adhesion on the micro-patterns and subsequently development of their proliferation and extracellular matrix, which were considered as important characteristics in their applications to tissue engineering.

Dermal fillers: facts and controversies

Dermal fillers have been used for decades in soft tissue augmentation. Currently, filler implementation is among the most common minimally invasive procedures for rejuvenation and body sculpturing. There is a broad variety of filler materials and products. Despite immense experience, a number of controversies in this topic exist. Some of these controversies are addressed in this review, for example, who should perform filler injections, the difference between permanent and nonpermanent fillers, the off-label use of liquid silicone, and the role of pain reduction. Implementation of guidelines and restriction of filler use by trained physicians can improve safety for patients.

Experimental and Clinical Efficacy of Two Hyaluronic Acid-based Compounds of Different Cross-Linkage and Composition in the Rejuvenation of the Skin

BACKGROUND

In the field of aesthetic medicine there is an increasing demand for safe and effective hyaluronic acid (HA) fillers to counteract the aging process.

METHODS AND AIMS

We designed a study to evaluate the safety and histological biocompatibility of Aliaxin® Global Performance, a cross-linked HA filler and Viscoderm® Skinkò E, a product composed of non-cross-linked HA and a complex including vitamins, antioxidants, amino acids and minerals injected into the skin of guinea pigs. Then, we translated our findings into the clinical setting, administering a combination of these compounds to patients seeking a facial rejuvenation procedure targeting moderate-to-severe wrinkles affecting the nasolabial folds.

RESULTS

The animal study showed that the two compounds did not induce any significant inflammatory reactions and increased collagen and elastic fibers in the skin. In the clinical setting, injection of Aliaxin® Global Performance, followed by Viscoderm® Skinkò E, resulted in a higher improvement in nasolabial fold hydration, trans-epidermal water loss and wrinkle aesthetic appearance, if compared with a protocol based on Aliaxin® Global Performance alone.

CONCLUSION

In summary, we show evidence on the safety and mechanism underlying two new HA-based compounds of different cross-linkage and composition, proposing that they can be safely used in combination in patients seeking facial rejuvenation procedures with long-lasting efficacy.

The utility of soft tissue fillers in clinical dermatology: treatment of fine wrinkles and skin defects

This review discusses treatment strategies for wrinkles and skin defects through an in-depth overview of current soft tissue fillers utilized within the fields of dermatology and plastic surgery. From the review, it is evident that the utilization of different materials for various skin abnormalities is extremely wide in scope. Many clinicians have adopted their own preferences based on not only the knowledge provided by their experience but also the respective profiles of each individual filler, including their efficacy, practicality and safety. With the ongoing emergence of commercially available products designed for soft tissue augmentation, the market will continue to present new and improved treatment options. Although the search for the perfect or most ideal filler is far from over, this review demonstrates that there are a number of commercially available products that are more than acceptable to both patients and clinicians in the treatment of wrinkles and other skin defects.

Clinical data on injectable tissue fillers: a review

Treatment with injectable tissue fillers for aesthetic purposes is increasingly popular. In parallel with this success, questions related to the safety of these treatments and the products involved are being raised more prominently. To gain insight in the safety aspects of injectable tissue fillers, we performed a literature review to collect studies reporting clinical data of injectable tissue fillers. We found several case reports where serious complications after more than three years are described. However, there are only a limited number of well-defined prospective clinical studies available with follow-up periods longer than three years. Furthermore, causes of complications, that is, treatment or product related, are often not specified in literature. Considering the intended functional period of fillers in combination with the known occurrence of long-term complications, there is a need for well-defined prospective clinical studies. In order to be able to discriminate between product failure (a product safety issue) or application methodology (a physician expertise or training issue), better identification of observed complications and whether they are product or treatment related, is needed. For the safe use of the fillers it is important that treatment with injectable tissue fillers is performed by a trained physician, who knows the product specifications and its applications.

Current status of surgery in dermatology

An article titled "Current issues in dermatologic office-based surgery" was published in the JAAD in October 1999 (volume 41, issue 4, pp. 624-634). The article was developed by the Joint American Academy of Dermatology/American Society for Dermatologic Surgery Liaison Committee. A number of subjects were addressed in the article including surgical training program requirements for dermatology residents and selected advances in dermatologic surgery that had been pioneered by dermatologists. The article concluded with sections on credentialing, privileging, and accreditation of office-based surgical facilities. Much has changed since 1999, including more stringent requirements for surgical training during dermatology residency, and the establishment of 57 accredited Procedural Dermatology Fellowship Training Programs. All of these changes have been overseen and approved by the Residency Review Committee for Dermatology and the Accreditation Committee for Graduate Medical Education. The fertile academic environment of academic training programs with interaction between established dermatologic surgeons and fellows, as well as the inquisitive nature of many of our colleagues, has led to the numerous major advances in dermatologic surgery, which are described herein.

Inflammatory nodules following soft tissue filler use: a review of causative agents, pathology and treatment options

Nodule development is a common complication following the use of fillers for soft tissue augmentation and is commonly categorized as inflammatory or non-inflammatory in nature. Inflammatory nodules may appear anywhere from days to years after treatment, whereas non-inflammatory nodules are typically seen immediately following implantation and are usually secondary to improper placement of the filler. Although inflammatory nodules are more common with permanent fillers such as silicone, inflammatory nodule development following administration of temporary fillers such as hyaluronic acid and collagen has also been reported. Treated many times with corticosteroids due to their anti-inflammatory properties, inflammatory nodules may be secondary to infection or biofilm formation, warranting the use of alternative agents. Appropriate and prompt diagnosis is important in avoiding delay of treatment or long-term complications for the patient. This paper addresses the etiology, development, and studied treatment options available for inflammatory nodules secondary to each of the major classes of fillers. With this knowledge, practitioners may expeditiously recognize and manage this common side effect and thus maximize functional and aesthetic benefit.

Nonanimal stabilized hyaluronic acid for tissue augmentation of the dorsal hands: a prospective study on 38 patients

BACKGROUND

Often ignored, hands are one of the most telltale signs of aging. This prospective study was initiated to evaluate the effect of subcutaneous hyaluronic acid (HA) injections in aging hands, with special attention to complications and long-term outcomes.

METHODS

Between January 2010 and December 2010, a total of 38 patients with skin phototypes II-IV and between 58 and 76 years old were treated with HA injection for aging hands. The quantity of injection never exceeded 1.0-1.5 ml HA per hand. A clinical follow-up was performed at 2 weeks, 4 weeks, 3 months, and 6 months after injection. Complications were reviewed for the whole series. At the first follow-up, 2 weeks after the procedure, ultrasound was carried out to determine if additional filling material was required. At each follow-up, patients were asked to fill out a satisfaction questionnaire.

RESULTS

Nine patients developed slight ecchymosis that disappeared after 1 week. No other complications were seen in the series. Pain during the injection and discomfort after the procedure were minimal. At the 2-week follow-up, after ultrasound control, nine patients received a complementary injection. At each follow-up, overall patient satisfaction was high and was validated by clearance of rhytids, veins, bony prominences, and dermal and subcutaneous atrophy.

CONCLUSION

Skin revitalization with injectable HA can improve the clinical appearance of the back of the hands. However, this therapy requires knowledge of the possible complications and their remediation as well as knowledge and respect of injected doses. Moreover, despite excellent results at each follow-up, the results of our series are not as good after 6 months, and a longer follow-up would be needed to determine if this procedure provides long-lasting benefit.

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 .

Clinical comparison of two hyaluronic acid-derived fillers in the treatment of nasolabial folds: Mesoglow® and IAL System®

Hyaluronic acid (HA) dermal fillers are widely used to reduce the appearance of aging. However, comparative research on the efficacy and safety of products of similar composition is limited. We compared outcomes achieved with two non-cross-linked HA fillers of almost identical composition, Mesoglow® and IAL System® . Forty subjects with visible nasolabial folds (NLFs) were enrolled in a randomized study. Wrinkle severity was rated using the 5-point Wrinkle Severity Rating Scale (WSRS). Each subject was injected with Mesoglow® in one NLF and IAL System® in the other. An optimal cosmetic result was established at two weeks after a second treatment. Participants were then reassessed at 2, 6, and 12 weeks, respectively, post-optimal cosmetic result using the WSRS. The degree of improvement was also assessed by subjects and investigators using the Global Aesthetic Improvement Scale (GAIS). At baseline, the mean WSRS score was 3.20 ± 0.41. At the optimal cosmetic result, 98% of subjects showed a 1- or 2-point change in WSRS score with either treatment. All subsequent WSRS scores were significantly improved over baseline for both treatments. There was no significant difference between treatments or improvement in WSRS score at any point in time. Investigator GAIS scores at weeks 4 and 6 were slightly but not significantly higher for Mesoglow®-treated skin. There was no significant difference in the frequency of local adverse responses. No serious systemic adverse events occurred. This study indicates that Mesoglow® and IAL System® are equally effective in achieving short-term correction of NLFs, but the longevity of their effects is limited.

Lip nodules caused by hyaluronic acid filler injection: report of three cases

Many dermal fillers have been used for reducing facial skin lines and for providing lip augmentation, and hyaluronic acid (HA) is one of the most widely used agents. One of the main commercial forms of HA is Restylane (Q Med, Sweden) produced by microbiological engineering techniques. Although HA is non-immunogenic, hypersensitivity and Granulomatous foreign body reactions have been reported. Herein, we report three female patients (average age 56 years) who presented with firm nodular lesions of the lip and a history of injection with HA (Restylane, Q Med, Sweden). Histopathologically, all cases showed pools of amorphous hematoxyphilic material surrounded by bands of densely collagenized connective tissue with no inflammation or foreign body reaction. Histochemical stains confirmed the presence of acid mucopolysaccharides such as hyaluronic acid. We conclude HA (Restylane, Q Med, Sweden) is an inert filler that may persist at an injection site, resulting in a tumor-like nodule.