Subcutaneous infection caused by Mycobacterium abscessus following botulinum toxin injections: A case report and literature review

The rapid development of cosmetic injections has led to an increased incidence of nontuberculous mycobacterial (NTM) infection.


| Strategy of literature search
We conducted a comprehensive search of PubMed/Medline from 2013 to 2023, using the following keywords for search strategy: cosmetic injection AND mycobacterium.We included only Englishlanguage articles and also reviewed the reference lists of all eligible studies and relevant reviews for additional citations.

| Case presentation
A 25-year-old Asian woman complained of multiple painful nodules on both cheeks about 10 days after injection of botulinum toxin (specific product name unknown) for masseter hypertrophy at a private clinic 4 months ago (Figure 1).The patient was given antibiotic treatment (oral clarithromycin) for 2 weeks in dermatology department, but she took medication irregularly and her symptoms did not improve.Then, the patient visited the infection department and was given another antibiotic treatment (oral azithromycin) for 2 weeks.Nevertheless, the patient's poor compliance to the regimen remained consistent, resulting in the persistence of the symptoms.
At the same time, the left nodule was punctured, and the pus specimens were cultured and then proven to be positive for M. abscessus after 10 days.The patient denied having a fever or experiencing any other systemic symptoms.Physical examination revealed multiple palpable subcutaneous erythematous nodules on both cheeks, without palpable lymphadenopathy.The patient also underwent an ultrasound examination of the nodules, which revealed three irregular nodules in the subcutaneous tissue of cheeks that measured 7 × 3 mm in the right (0.7 mm from the surface of the skin), 11 × 4 mm (0.7 mm from the surface of the skin), and 9 × 4 mm (3.4 mm from the surface of the skin) in the left (Figure 2).For further treatment, the patients went to plastic surgery department and asked for surgical excision.The tissue specimen was sent for cultures of common bacteria and fungi, and the results showed that M. abscessus was found in the left tissue but revealed negative in the right tissue.Following consultation with the expert in our hospital's infection department, 300 mg qd of clarithromycin was prescribed for 6 months.The patient was discharged on postoperative Day 2 and took her antibiotic prescription under the advice.She has had almost 3 months of follow-up with no signs of infection and underwent an excision surgery for a dog-ear deformity on her left cheek (Figure 3).

| Results of literature characteristics
A total of 24 cases across 18 studies of cutaneous NTM infection after cosmetic injections reported from 2013 to 2023 were identified in the search. 4-21  The characteristics of the included studies are summarized in Table 1.The majority of the patients were female (23 out of 24 patients), with ages ranging from 28 to 56 years old.Of these 24 cases, eight patients were infected after autologous fat grafting, seven were after botulinum toxin injection, five were after dermal filler, and the rest were after other procedures including hydrogel, poly-L-lactic acid, argireline, lipodissolve injection, and hair transplant.
None of these patients had human immunodeficiency virus (HIV) infection or immunodeficiency.The time from the onset of symptoms to the diagnosis of NTM was from 1 day to 2 months, and most were within 1 week.Erythema and nodules with/without tenderness were the two most common skin lesions, and some patients also present with subcutaneous abscesses, papules, and itching.The most commonly involved sites were face, followed by breast, extremeties, and buttock.Among 22 patients with detectable NTM species, the most common pathogen was Mycobacterium abscessus, followed by

| DISCUSS ION
Through this study, we reported a case of infection of M. abscessus after botulinum toxin injection for masseter hypertrophy and summarized 24 cases from 18 studies of subcutaneous infections caused by NTM following cosmetic injections.
Based on colony form, growth rate, and pigment, NTMs are divided into four types. 22The rapidly growing mycobacteria (RGM), of which the primary clinically significant species are M. abscessus, M. chelonae, and M. fortuitum, 23 are the principal pathogenic group of invasive operations, which is consistent with the findings of our literature review.In addition, relatively rare cases of M. immunogemom, M. wolinskyi, and M. mucogenicum have been reported, and all of them were RGM and had comparable characteristics, indicating that the number of infected species is increasing and changing.
The source of infection is worthy of discussion and attention.
One of the most common causes of infection is a failure to follow aseptic procedures during invasive procedures, such as non-standard aseptic injection, equipment contamination, or intraoperative infection. 6This is the primary suspect factor in most cases, which also reminds operators to adhere the idea of sterility in all aspects when performing cosmetic injection, from skin disinfection preparation to thorough sterilization of used equipment.Another possible source of NTM infection is the use of tap water.The application of nonsterile ice to the skin prior to injection was found as a potential infection source in one case.The practitioner's contamination of his non-sterile gloves or rinsing of nonsterile equipment used in the procedure are two additional potential for tap water exposure at the injection site.Once tap water source contamination is identified, it is important to pay attention to it since it frequently results in clustered diseases.In our case, we suspected that the source of infection was non-standard aseptic operation or the contaminated medication as the injection was performed in a private clinic and with an unknown product.
The majority of the period between the injection and the onset of symptoms was within 1 week, although there were few cases where nodules developed more slowly and appeared 2 months after the injection.Therefore, when patients experience unexplained infection at The treatment of NTM infection is also challenging.NTM are intracellular colonies resistant to conventional antituberculosis medications due to their high hydrophobicity on the cell surface and cell wall permeability barrier. 24Through our review of the literature, macrolides and aminoglycosides were the antimicrobials most frequently employed.The choice of the agents usually depends on the doctor's experience and is directed by the patient's tolerability.Although surgical interventions along with medication were recommended in cases of NTM infection associated with foreign body material for better prognosis, we think the indications of this intervention should take the areas and symptoms into considerations. 19If mild erythema and nodules were presented on the exposed areas like the face, scars, and pigmentation are unavoidable after surgery and will influence appearance; therefore, only medication therapy would be a good choice.If abscesses occurred, it is better to perform debridement and drainage to avoid dissemination and deformity.In our case, the patient was annoyed with the persistent nodules on the face and therefore chose a surgical incision.
Infection following cosmetic facial injections has a significant social TA B L E 1 Summary data of nontuberculous mycobacterial (NTM) infection after cosmetic injection procedures in the literature.and economic impact on patients. 25Further research into the most effective treatment for NTM infection is needed, especially considering the apparent increase in incidence of this form of infection.

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et al. macrolides, fluoroquinolones, tetracyclines, rifampin, diarylquinoline, ethambutol, aminoglycosides, trimethoprim-sulfamethoxazole, and cephalosporins, in which macrolides and aminoglycosides were most frequently used.The patient follow-up period ranged from 30 days to 18 months.All patients were successfully cured with only one patient reported with recurrence followed by a secondary antibiotic therapy and surgery.
the injection site within a few months after injection, the possibility of NTM infection should be considered.Skin lesions presented as nonspecific manifestations in most cases, there by rendering the diagnosis F I G U R E 2 Ultrasound examination of the nodules.F I G U R E 3 Photos of the patient at a 3-month follow-up after treatment.(A) Right cheek.(B) Left cheek.more intricate.Mild cases may present with skin erythema and nodules with/without tenderness, and in severe cases, even accompanied by abscesses or ulcers, causing both physical and emotional distress.
dence of NTM infections has booming increased during the past decades is the rapid development of cosmetic injections.This case report and literature review aims to raise the awareness of surgeons about NTM infection after nonsurgical cosmetic injections, and to emphasize the importance of early diagnosis and timely treatment.Further studies are needed to provide evidence-based guidelines for better managing this continuously increasing complication and form consensus.AUTH O R CO NTR I B UTI O N SYanting Ou and Dandan Liu performed the study and wrote the manuscript.Jun feng, Yihan Zhang, Lin Luo, and Mengfan Wu participated in the design.Tingyin Lin and Xiangwen Xu revised the paper.Yongyan Cui designed the study.All authors contributed to the article and approved the submitted version.