Letter: Foreign Body Reaction to Hyaluronic Acid Filler Injection: In Search of an Etiology

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.

Post-injection syringe bacterial contamination of hyaluronic acid fillers

AIMS

Hyaluronic acid (HA) gel fillers are the most commonly used filler materials for dermal purposes to augment soft tissue due to their superior properties and advantages over other alternative filling materials. One of the key drawbacks associated with the use of fillers is contamination and possible subsequent infection.

METHODS

A prospective cross-sectional study conducted in Renew Cosmetic Clinics and King Abdulaziz University, Faculty of Medicine, female section from November 2019 to March 2020.

RESULTS

A total of 50 samples with different concentrations (from five different brands) of hyaluronic acid gel fillers were collected. Samples were taken at four different time points: before injection, immediately after injection, 1 month after injection, and 3 months after injection. The 50 samples were injected into nine different sites and collected from 27 females, aged between 18-55 years. No bacteria were detected in the culture media from any samples from the aerobic and anaerobic culture plates.

CONCLUSION

Our study did not find any evidence of contamination associated with the reuse of HA gel fillers regardless of the concentration and the injection site. Applying appropriate sterilization procedure for HA gel fillers extends its usability. There was no correlation between the length of storage time and the risk of contamination.

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.

An unusual and delayed complication of hyaluronic acid filler injection: a case report

48-year-old female with facial granulomatous nodules and fungal/bacterial infection after hyaluronic acid injection. She underwent anti-fungal/antibacterial therapy and local excision. The proposed mechanisms include inflammatory foreign body reaction and pathogen contamination. Providers must exercise caution with the use of facial fillers and demonstrate expertise in avoiding and managing potential complications.

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.

Complications of injectable fillers, part I

Dermal filling has rapidly become one of the most common procedures performed by clinicians worldwide. The vast majority of treatments are successful and patient satisfaction is high. However, complications, both mild and severe, have been reported and result from injection of many different types of dermal fillers. In this Continuing Medical Education review article, the author describes common technical errors, the signs and symptoms of both common and rare complications, and management of sequelae in clear, easily adaptable treatment algorithms.

Probable biofilm formation in the cheek as a complication of soft tissue filler resulting from improper endodontic treatment of tooth 16

Injectable filling agents offer the promise of a better appearance without surgery and, among them, hyaluronic acid is the most commonly used. Although complications are rare, it is necessary to know the possible side effects and complications in order to be prepared for their management. That is why many researchers have been focusing on the interactions between hyaluronic acid and pathogens, inflammatory mediators, the immune system, and markers of oxidative stress to achieve efficient drug delivery, given that hyaluronic acid has widening applications in the field of nanomedicine. Here we report the case of a 37-year-old female patient who returned to our clinic with an abscess in her left cheek 3 months after a deep injection of 1 mL of stabilized hyaluronic acid in both cheeks. Steroid and antibiotic therapy was initiated without success, and abscess drainage was performed. Extraction of tooth 16 was performed 11 days after insertion of drains into the abscess. Laboratory blood tests showed acute inflammation of presumed bacterial etiology. Microbiological examination of pus was negative. Bacterial cultures were found in the extracted tooth. After antibiotic therapy, a complete reversal of the pathological process was observed. The present report highlights the need to assess periodontal problems prior to any aesthetic facial treatment. Analyses of further case reports and clinical studies are necessary to understand the potential role of hyaluronic acid in the formation of biofilm, and how to avoid this complication, thereby increasing the safety of hyaluronic acid-based procedures.