Keywords lip augmentation - fillers - nodules - granulomas - systematic review
The lips are a central and defining aspect of an individual's face and have long been a target for enhancement and antiaging techniques. Due to the multitude of treatment modalities available today, treatments to the lips are becoming increasingly more common. There are numerous materials for lip augmentation including hyaluronic acid (HA), fat grafts, silicone, polyacrylamide, polymethylmethacrylate (PMMA), and poly-L-lactic acid (PLLA). Injections are used to treat lip asymmetry, lack of vermillion volume, vertical lip lines, downturned oral commissures, and/or an elongated upper lip, features which are normal consequences of aging.[1 ] Lip enhancement or augmentation with injectable fillers is rising in popularity as these treatments achieve rapid results with generally predictable outcomes.[2 ] This aesthetic treatment is also favorable due to its less invasive nature and minimal down time compared with surgical cosmetic procedures.
Soft tissue fillers are generally well-tolerated and major adverse events are rare. Mild side effects typically include limited and transient swelling, bruising, pain, and erythema. More severe complications include infection, nodule formation, vascular occlusion, and pigment changes.[3 ] Nodule formation may be characterized as early or delayed (4 weeks and later postinjection).[4 ] The incidence of delayed-onset nodules is uncommon and is reported to be 0.1 to 1.0%.[5 ] Delayed-onset nodules may be identified through histological analysis as foreign-body granulomas. If nodules or granuloma formation occur, they can be treated with intralesional steroids or hyaluronidase injections (for HA filler). However, if these treatments repeatedly fail, surgical excision may be required.[3 ]
[6 ]
Delayed-onset granuloma formation has been a rarely cited complication of lip augmentation with filler. In this review, we aim to perform a thorough systematic review of the published literature related to nodule or granuloma formation after lip filler injections. Our goal is to determine the details associated with this complication including symptom description, time of onset, nodule characteristics, treatment, and outcomes. Since various terms for nodular formations have been used across providers, including lumps, bumps, nodules, or granulomas, these terms will be interchangeably used throughout this study unless otherwise specified. By gaining a better understanding of this rare but challenging outcome of lip fillers, providers can prevent future complications and provide patients reliable information regarding potential side effects.
Methods
Search Strategy
A systematic review of the published literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to assess the association of granulomas with HA lip fillers. The literature search was performed in April of 2021, which included PubMed, ScienceDirect, Embase, Google Scholar, and Cochrane databases. The Medical Subject Headings (MeSH) terms used included the following terms: “lip filler,” “hyaluronic acid,” “lip injection,” “lip augmentation,” “silicone,” “poly-L-lactic acid,” “calcium hydroxyapatite,” “polymethylmethacrylate,” “complications,” “reaction,” “granuloma,” and “nodule.” The goal of the search was to compile and assess all of the published literature consisting of original articles including case reports, clinical trials, case series, and prospective case studies related to granuloma formation after filler lip augmentation.
Study Selection
Studies were included if they met the following criteria: (1) described granuloma formation after lip filler, (2) were published between 2000 and 2021, and (3) included specific patient case information. Exclusion criteria included studies that: (1) were not published in English, (2) included nonhuman subjects, (3) were abstracts, communications, letter to the editor, or review articles, (4) did not report on location, onset, and treatment of granuloma, and (6) those discussing granulomas in other areas of the face.
Data Abstraction
Titles and abstracts were screened for relevance by two separate reviewers (L.N.T. and K.C.M.). Of the selected articles that met the predetermined criteria, the full-text articles were retrieved and then independently reviewed by the two reviewers. Any discrepancies were resolved with the third investigator (A.G.). All studies which met the predetermined criteria were included in the final analysis. Relevant information from each included article was extracted which included author name, year of case reporting, patient age and sex, patient comorbidities, filler brand used, volume injected, site of injection, time of symptom onset after injection, presence of swelling or pain, number of nodules, nodule description, nodule duration/size, excision technique, treatment, and outcome. A summary of extracted information is depicted in [Table 1 ].
Table 1
Summary of the post-HA filler granuloma presentation and outcome
Author (first author)
Year
Country
Age
Sex
Brand
Site of injection (lips)
Onset (time after injection, mo)
Site of nodule (lips)
HAdase given?
Treatment start after Injection (mo)
Surgical treatment
Other treatments
Outcome
Kaczorowski[26 ]
2019
Poland
52
F
NA
Both lips, NLF
24
Right buccal area
No
24
Excision
NA
Resolved
Alcântara [27 ]
2017
Brazil
54
F
Perlane
Both
12
Both
No
NA
Excision
NA
Resolved
Rongioletti[15 ]
2015
Italy
72
F
NA
Upper
36
Upper
No
36
Excision
NA
Resolved
Curi[10 ]
2015
Brazil
65
F
Restylane
Upper
144
Upper
Yes
12
Punch biopsy
Oral steroids for 2 months
Remission after 3 months
Fernández-Aceñero [28 ]
2003
Spain
48
F
Restylane
Upper
2
Upper
No
2
Punch biopsy
NA
Lost to follow-up
Edwards[29 ]
2006
United States
74
F
Restylane
Both
6
Lower
No
6
Excision
NA
Resolved
Farahani[30 ]
2012
United States
55
F
Restylane
Both
4
Upper
NA
4
Excision
NA
Resolved
57
F
Restylane
Both
24
Lower
NA
24
Excision
NA
Resolved
56
F
Restylane
Both
NA
Lower
NA
NA
Excision
NA
Resolved
Alijotas-Reig[8 ]
2013
Spain
47
F
Restylane
Both lips, NLF, cheeks
15
Upper
No
15
Excision
Antibiotics (quinolones) and NSAIDs: no effect, oral prednisone + hydroxychloroquine (400 mg/d): nodules resolved
Resolved
50
F
Restylane
Both
6
Upper
No
6
NA
NA
NA
Park[31 ]
2011
South Korea
23
F
Unspecified
Lower
36
Lower
Yes
36
Excision
NA
Resolved
2018
United Kingdom
24
F
NA
Upper
NA
Upper
No
NA
NA
NA
NA
43
F
NA
Upper
NA
Upper
No
NA
NA
NA
NA
Alghonaim[32 ]
2016
Canada
52
F
Restylane
Both
1
Lower
NA
36
Excision
NA
Resolved
Abbreviations: F, female; NA, not available or reported.
Results
Study Selection
The initial search for filler-related nodules or granulomas yielded 2,955 articles. After removing 1,016 duplicates, 1,939 studies were screened by title and abstract. A total of 1,852 studies were eliminated based on the predetermined inclusion and exclusion criteria. Five articles were unable to be retrieved. The remaining 82 articles underwent full-text review. Fifty-three studies were excluded due to wrong treatment area of the face (n = 17), do not include specific case information (n = 14), wrong study design (n = 10), wrong outcomes (n = 2), abstract only (n = 6), and published in a language other than English (n = 4). A total of 29 articles were included in the final analysis. [Fig. 1 ] demonstrates the breakdown of the literature search.
Fig. 1 PRISMA 2020 flow diagram of screening process.
Study Characteristics
An overview of the study characteristics is summarized in [Table 1 ] for HA and in [Table 2 ] for non-HA. Of the 29 included studies, there were 68 cases reported on the incidence of nodule or granuloma formation following lip augmentation with dermal filler. This selection of 29 articles included 15 (51.7%) case reports (articles containing the description of one case) and 14 (48.3%) case series (articles evaluating more than one case). Most studies originated from Spain (n = 6; 20.7%). Four were from the United States, and many other countries were also represented ([Fig. 2 ]). The article publication years ranged from 2003 to 2019 ([Fig. 3 ]).
Fig. 2 Country of study publication.
Fig. 3 Number of study publication by year.
Table 2
Summary of the post-non-HA filler granuloma presentation and outcome
Author (first author)
Year
Country
Age
Sex
Type of filler
Site of injection (lips)
Onset (time after injection, months)
Final treatment
Outcome
Wang[33 ]
2018
United States
63
F
Silicone
Upper lip, NLF
36
Surgical
Resolved
Sanchis-Bielsa[12 ]
2006
Spain
70
F
Collagen
Upper lip, NLF
12
Systemic steroids
Resolved
43
F
Silicone
Both lips
30
Systemic steroids
Resolved
Schmidt-Westhausen[34 ]
2004
Germany
56
F
Silicone
Lower lip
12
Surgical
Resolved
Hamilton[35 ]
2008
France
58
F
PLLA
Both lips
18
Intralesional steroids
Resolved
Dijkema[36 ]
2005
Netherlands
64
F
PLLA
Upper lip
14
Surgical
Not reported
Bigatà [37 ]
2001
Spain
30
F
Silicone
Lips (unspecified)
8
NSAIDs, systemic and intralesional steroids
Resolved
Maly[38 ]
2002
Israel
32
F
Silicone
Upper lip
24
–
Not reported
Ficarra[16 ]
2009
Multiple
5656
F
Silicone
Both lips
120
NSAIDs, systemic steroids
Persistent
34
M
Silicone
Upper lip
84
Surgical
Resolved
50
F
Silicone
Lower lip
60
Intralesional steroids
Stable (asymptomatic and no change)
39
F
Silicone
Lower lip
84
Surgical
Stable
38
F
Silicone
Lower lip
60
Surgical
Resolved
52
F
Silicone
Upper lip
12
Surgical
Lost to follow-up
77
F
Silicone
Upper lip
180
Surgical
Lost to follow-up
Alijotas-Reig[39 ]
2009
Spain
65
F
PLLA
Both lips, NLF
15
HCQ, systemic steroids, NSAIDs
Remission
60
F
PLLA
Both lips, NLF
60
Intralesional steroids, HCQ, allopurinol, prednisone, minocycline
Minor bouts
48
F
PLLA
Lips (unspecified)
10
Intralesional steroids
Remission
39
F
PLLA
Lips (unspecified)
6
Intralesional steroids, NSAIDs
Recurrent bouts
59
F
PLLA
Both lips, NLF
17
Intralesional steroids, NSAIDs
Remission
Akrish[40 ]
2009
Israel
41
F
PAIG
Lips (unspecified)
12
Surgical
Not reported
43
F
PAIG
Upper lip
−
Surgical
Not reported
Baumann[41 ]
2003
United States
31
F
Silicone
Both lips
6
Imiquimod topical cream
Resolved
Da Costa Miguel[42 ]
2009
Brazil
56
F
PMMA
Lips (unspecified)
12
Surgical
Not reported
Dionyssopoulos[7 ]
2007
Multiple
45
F
PLLA
Both lips
4
Intralesional steroids
Significant volume reduction, granulomas not completely resorbed
Friedmann[43 ]
2016
Multiple
46
F
Silicone
Both lips, NLF
12
Intralesional 5-FU
Significant reduction in lesion size/firmness
47
F
Silicone
Upper lip
120
Intralesional 5-FU
Progressive improvement
Weyand[44 ]
2008
Germany
62
F
Mixed (HA + HEMA + EMA)
Lips (unspecified)
0
Surgical, antibiotics, intralesional steroids
Persisted (physical + psychological complications)
Grippaudo[9 ]
2014
Italy
28
F
Silicone
Lips (unspecified)
12
Antibiotics
Resolved
58
F
Mixed (silicone + HA + EMA + HEMA)
Lips (unspecified)
–
Antibiotics
Resolved
34
F
PAAG
Lips (unspecified)
0.25
Surgical
Resolved
45
F
PAAG
Lips (unspecified)
24
Antibiotics, surgical
Resolved
55
F
PAAG
Lips (unspecified)
0.25
Antibiotics, surgical
Resolved
43
F
PAAG
Lips (unspecified)
72
Surgical
Resolved
40
F
PAAG
Lips (unspecified)
36
Antibiotics, surgical
Resolved
32
F
Mixed
Lips (unspecified)
12
Antibiotics
Resolved
48
F
Mixed
Lips (unspecified)
60
Antibiotics, surgical
Resolved
45
F
Collagen
Lips (unspecified)
12
Systemic steroids
Resolved
38
F
PAIG
Lips (unspecified)
60
Systemic steroids
Resolved
73
F
PAIG
Lips (unspecified)
36
Filler for asymmetry
Resolved
28
F
PAIG
Lips (unspecified)
24
Surgical
Resolved
55
F
PAIG
Lips (unspecified)
60
Antibiotics, surgical
Resolved
Sanchis-Bielsa[12 ]
2009
Spain
63
F
Silicone
Lips (unspecified)
168
Systemic steroids
Partial healing
70
F
Collagen
Lips (unspecified)
24
Systemic steroids
Resolved
71
F
Silicone
Lips (unspecified)
2
Systemic steroids
Not resolved
54
F
Silicone
Lips (unspecified)
1
Systemic steroids
Partial healing
Martin[45 ]
2018
United Kingdom
24
F
HA (unspecified)
Upper lip
NA
NA
NA
43
F
HA (unspecified)
Upper lip
NA
NA
NA
67
F
HA + acrylic
Lower lip
NA
NA
NA
62
F
HA + acrylic
Upper lip
NA
NA
NA
44
F
Silicone
Lower lip
NA
NA
NA
36
F
CaHA
Lower lip
NA
NA
NA
48
F
Collagen
Lower lip
NA
NA
NA
36
F
Silicone
Upper lip
NA
NA
NA
Abbreviations: CaHA, calcium hydroxyapatite; EMA, ethyl-methacrylate; F, female; FU, fluorouracil; HA, hyaluronic acid; HEMA, hydroxyl-ethyl-methacrylate; M, male; NA, not available or reported; PAAG, polyacrylamide gel; PAIG, polyalkylimide gel; PLLA, poly-L-lactic acid; PMMA, polymethylmethacrylate.
Case Characteristics
There were 67 (98.5%) females and one (1.5%) male described in our cases. The average age was 50.0 years (range: 23–77 years). The mean time of onset of masses or nodules was 34.4 (n = 55) months. Most patients presented with swelling, asymmetry, or erythema of their lips. Twenty-six cases (38.2%) presented with multiple nodules, 19 (27.9%) reported single nodules, and 23 cases (33.8%) did not report on the number of nodules. Masses were frequently described as discrete, indurated, mobile, firm, and slowly growing.
A histological analysis of 37 cases was reported. Thirty-one (83.8%) of these confirmed a foreign-body granuloma. The other cases reported extensive or chronic inflammation, sarcoid-like reaction, and a pseudocystic, fibrous-structure-containing translucent, viscous material that stained positive for Alcian blue (a marker for HA).
Only one case reported on the injection volume, which was 3 mL for both lips.[7 ] No studies reported on the method of injection or qualifications of the injector. Regarding the initial treatment area for augmentation, many studies reported injecting in the “lips” and did not specify if it was both lips and one lip. The frequency of other injected areas is displayed in [Fig. 4 ].
Fig. 4 Initial site of injection for augmentation.
Product Used
The most commonly reported dermal filler product used was silicone (21/66, 31.8%) followed by HA (14/66, 21.2%). Various other dermal fillers were used ([Fig. 5 ]).
Fig. 5 Reported filler type used. CAHA, calcium hydroxy apatite; HA, hyaluronic acid; Mixed, combination of HA and hydroxy-ethyl-methacrylate (HEMA) and ethyl-methacrylate (EMA); PAAG, polyacrylamide gel; PAIG, polyalkylimide gel; PLLA, poly-L-lactic acid, PMMA, polymethyl-methacrylate microspheres.
Treatment
Treatment typically consisted of oral antibiotics, intralesional steroids, or oral steroids ([Fig. 6 ]). For instance, Alijotas-Reig et al initially treated a case of multiple nodules with antibiotics (quinolones) and nonsteroidal anti-inflammatory drugs (NSAIDs), which had no effect.[8 ] However, when oral prednisone and hydroxychloroquine (400 mg/day) were added, many of the nodules resolved. Grippaudo et al described a case with “multiple angry red lumps” 12 months following lip augmentation, which was successfully treated with three rounds of antibiotics.[9 ] Curi et al reported a non-well-defined nodule which was initially evaluated by a punch biopsy. This identified the foreign granuloma which was successfully treated with oral steroids for 2 months.[10 ] Goldman and Wollina reported granulomas after PMMA injection which was first treated by intralesional 1,064 nm Nd:YAG laser in combination with suction using a blunt liposuction cannula either alone or combined with surgery.[11 ] Sanchis-Bielsa et al described a nodule with associated swelling that partially resolved with oral steroids (30–90 mg/day) for 10 to 15 days.[12 ] Surgical treatment was often offered to those with persistent nodules (25/66, 37%), which led to complete resolution of the nodule.
Fig. 6 Treatment of cases. FU, fluorouracil.
Outcomes
A summary of the outcomes is reported in [Table 3 ]. In most cases, there was resolution of the nodule(s) or remission (42/68, 61.8%). Eight cases reported only partial healing or persistent disease. Two cases reported a significant reduction in lesion size. Seventeen cases were lost to follow-up or did not report on the outcome.
Table 3
Outcomes of reported cases
Outcome
Number of cases (%)
Resolved or remission
42 (61.8%)
Incomplete resolution
(partial, persistent disease, minor bouts)
7 (10.3%)
Significant reduction in lesion size or progressive improvement
3 (4.4%)
Lost to follow-up
3 (4.4%)
Not reported
13 (19.1%)
Discussion
Lip augmentation with dermal fillers is rising in popularity. This systematic review analyzed reported cases of granulomas or nodules secondary to any dermal filler for lip augmentation. Of the 66 cases, 31 (47.0%) confirmed the presence of a delayed-onset foreign-body granuloma. Of note, not all nodules are considered granulomas.
Nodules following treatment of filler are commonly categorized as inflammatory or noninflammatory in origin.[13 ] Inflammatory nodules may occur days to years after treatment as a result of host response to a foreign body. In contrast, noninflammatory nodules commonly occur immediately after treatment and are typically caused by improper placement of the filler material. These cases may not be reported in the literature as observation, massage, or hyaluronidase may resolve these nodules. Temporary and biodegradable HA should have a minimal foreign-body response compared with permanent and nonresorbable fillers such as silicone.[14 ] However, our study demonstrates that treatment with HA does not preclude a risk of granuloma formation.[15 ]
Diagnosis of lip nodules can be challenging as patients may not associate them with filler treatment performed weeks, months, or years prior. A broad range of differential diagnoses commonly includes abscesses, sialadenitis, mucocele, benign salivary gland neoplasm, or malignancy. Infection can present early or late in the clinical course and are more commonly single nodules. The involvement of multiple sites more likely suggests a foreign-body granulomatous response. Timely and proper diagnosis of these masses is crucial as they may mimic a neoplasm, which is particularly important given the generally older age group of these patients.
Silicone liquid (dimethylpolysiloxane) has been widely used for soft tissue augmentation. When it was first introduced in the late 1950s, it was considered safe as it was not known to elicit pathological disease in humans. Additionally, non-medical-grade silicone fluid was used in many patients. Years later, the term “siliconoma” was coined to describe the granulomatous reactions in soft tissues of patients who had received liquid silicone injections.[16 ] The pathogenesis of silicone granuloma is unknown, but factors such as the volume of the injection, impurities present in the fillers, and the physical properties of fillers have been reported to affect granuloma formation.[17 ] Silicone granulomas have been reported in other areas of the face such as the eyelids and cheek and the onset ranged from 5 months to 15 years, which is similar to that of our observed cases.[18 ]
[19 ] Liquid silicone injections remain controversial, particularly in countries where there is inadequate control of quality of material used for soft tissue augmentation.
Several hypotheses have been suggested for the pathogenesis of granulomatous reactions to HA. HA is a polysaccharide that is fermented from bacteria and impurities from this process may elicit a hypersensitivity response, particularly in patients who have undergone repeated injections.[15 ]
[20 ] Additionally, during the production of HA filler products, stabilization through a cross-linking process occurs, which allows the product to be resistant to natural hyaluronidases. Over time, the breakdown and byproducts of the cross-linked material may induce a host inflammatory response.[21 ] Lastly, bacteria inoculated during the injection may form a biofilm. The biofilm surrounding the HA material creates a matrix that can inhibit natural hyaluronidases from degrading the HA. These biofilms can induce a minimal infection with little host response, making them asymptomatic for months or even years.[22 ] In our cases, microscopic examination of the nodules confirmed the presence of HA years following treatment, indicating failure in the degradation process. A subsequent delayed foreign-body tissue reaction to biofilm could have been elicited in the months or years following initial injection.
Restylane was the most common HA filler used in our reported cases. One explanation of this finding may be due to the rheological properties (i.e., cohesion) or processing technologies of the fillers. Popular Restylane products for lip augmentation are non-animal HA, while Juvéderm uses Hylacross and Vycross cross-linking technologies.[23 ] Bhojani-Lynch reported a case where two different brands (Teosyal Puresense Ultra Deep and Belotero Intense) were injected into various parts of the face during the same session and only areas treated with Teosyal triggered a hypersensitivity reaction characterized by diffuse redness and swelling without lumps. The authors suggest that reactions to HA fillers may be attributed to rheological or processing technologies of the fillers.[24 ] Additionally, more reports of Restylane may be published as it was Food and Drug Administration-approved and more widely used earlier than Juvéderm and Belotero. In our cases, granuloma formation was more likely found in the upper lip compared with the lower lip, which may be due to the fact that the upper lips are more commonly treated. While our review includes studies involving granuloma formation following the use of calcium hydroxyl apatite and PLLA, current standard practice does not use these products.
Many patients were initially treated with nonoperative methods such as NSAIDs, antibiotics, and systematic and/or intralesional steroids. Laser therapy has also been successfully used.[11 ] Goldman and Wollina reported the use of a subdermal, intralesional 1,064 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser in combination with a blunt liposuction cannula suction in 81 patients with facial lumps or granulomas following PMMA. The procedure was well tolerated and 86.4% of the patients were satisfied.[25 ] In our subset of patients, many ultimately required surgical removal of the granuloma, particularly if there was a single nodule. For those with multiple nodules, more aggressive treatments were pursued, including intralesional 5-FU.
Limitations
This systematic review has some limitations. The sample size is small with only 66 cases of dermal filler-related lip granuloma or nodules reported in the literature. There was also a lack of uniformity in describing the cases such as time of onset versus time the patient presented for care. There are many factors that determine the likelihood of dermal filler complications such as injector experience, training, and techniques used. However, this information was not available in any cases, potentially owing to the long duration from initial injection to time of onset of nodule(s). Some studies reporting on lip nodules or granulomas secondary in filler were excluded from our study because they did not provide enough patient case information. Therefore, our review may not have included all reported cases in the literature.
Conclusion
Understanding the sequelae of lip augmentation with dermal filler products allows clinicians to provide safe and effective treatment. Nodules that present months to years following filler treatment may represent a foreign-body granuloma. A combination of oral antibiotics, intralesional or oral steroids, and surgical excision successfully treated the majority of cases in our study. Future studies evaluating the development of granulomas should include treatment injection methods and techniques to better elucidate potentially related causes.