Understanding and Comparing Current Practice for Ear Keloid Scars: A Narrative Systematic Review

Abstract

A keloid scar is a benign fibroproliferative disorder that is characterized by excessive tissue growth beyond the original wound. The psychosocial and surgical challenges that arise can present potentially devastating long-term consequences for patients, particularly in demographics with a high incidence of keloid scar formation. Considering the high incidence of keloids with an estimated 11 million cases annually, particularly in those of Asian and African backgrounds, an understanding of their exact pathophysiology remains challenging. Piercing-induced keloids of the ear are a common cause of ear keloids, yet the exact mechanism and optimal treatments are of considerable debate. This narrative review aims to evaluate current treatment modalities for ear keloids, focusing on their association with ear piercings and the implications for management.

A systematic review of Medline, Embase, and Mendeley identified 26 studies, covering a range of surgical and non-surgical treatment methods, indicating a considerable recurrence rate, with an average of 20.3%. Surgical excision remained the primary treatment modality, which was often accompanied by adjunctive therapies such as steroid injections and radiotherapy. Fractional carbon dioxide laser therapy may also be a useful treatment modality with fewer potential complication risks.

Overall, the findings identified significant variability in treatment protocols and outcomes, underscoring the need for personalized approaches based on keloid characteristics and patient preferences. Ultimately, the review highlights the importance of further research to establish standardized treatment protocols for ear keloid scars and to understand the role of piercing-specific pathophysiology in improving patient outcomes.

Introduction

Keloid scars are a benign, fibroproliferative disorder characterized by hypertrophy and margins beyond the original wound¹⁾. The estimated incidence varies, although it is thought that around 11 million individuals develop keloid scarring per year worldwide, with those of African or Asian descent at heightened risk^2,3). They present typically as a raised and firm entity at the site of scarring and are, on occasion, accompanied by pruritus and pain⁴⁾. Such scars rarely spontaneously regress and often continue to grow unless treated. Keloids, therefore, have the potential to cause a significant number of psychosocial complications for individuals internationally⁵⁾.

Despite extensive research on keloids, the exact pathophysiology remains unclear. It is thought that keloids develop due to an inflammatory response to an abnormal reaction of tissue to certain traumas in those with a genetic predisposition⁶⁾. A common inciting trauma is body piercings. Piercings, particularly in the ear, are a common form of jewelry, culturally and historically, to enhance aesthetics and beauty. Earlobes are the most common site of keloid scars secondary to piercing⁴⁾. The trauma induced by piercing is unique in that it involves the creation of a channel―known as a piercing tract―through the full thickness of the tissue. Non-sterile piercing conditions may contribute to exaggerated inflammatory responses, particularly in the presence of persistent foreign material. In cases where the tract closes, epithelial cells that have formed within the closed tract may continue to produce products such as keratin, which accumulate, acting as a nidus for chronic inflammation or immune activation. The ultimate result is the formation of scar tissue from the anterior to the posterior aspect of the ear, predisposing individuals to keloid development⁷⁾.

There exists no standardized method for treating keloid scars, due to a wide variety of different feasible options, and available evidence yet to suggest a single optimal therapy⁸⁾. Treatment method varies with the site of the keloid, but also based on the institution, available resources, and the clinician's experience and preference. Commonly used techniques include surgery combined with steroid or with post-operative radiotherapy, compression, or laser. Non-surgical methods include multiple steroid or 5-fluorouracil (5-FU) injections, compression alone, or cryotherapy^8,9). Despite so many management options, the treatment of ear keloids remains a challenge due to the predisposition of recurrence, a risk often enhanced by trauma from the treatment method itself. The recurrence rates for keloids have varied significantly across the literature, with some studies describing ranges as high as 20%-100%^1,2). Therefore, the factors that affect wound healing, and therefore keloid scar formation, would potentially play a key role in recurrence.

Given the likely distinct pathophysiology of piercing-induced keloids of the ear, evaluation of treatment regimens should be done with this in mind. Evidence-based medicine forms the basis of modern healthcare, and therefore, it is important to compare different management strategies to seek the most optimal. Currently, no study has evaluated the current evidence base for the pathophysiology and treatment of piercing-induced keloid scars of the ear. Thus, we aim to perform a narrative review of the literature to provide an insight into the current treatment modalities for these cases and for ear keloids in general.

Methods

Aims

This narrative review aimed to evaluate the current approaches to managing ear keloids and the outcomes for these patients. Additionally, the role of ear piercing in the pathophysiology of keloids will be reviewed, as well as how this might affect management.

Literature search

A Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA)-compliant systematic literature search was carried out in October 2024 by two independent reviewers (HH and LD). The databases Medline, Embase, and Mendeley were searched for articles published between 2014 and 2024. The following search terms were used to retrieve the relevant articles: “ear,” “helix,” “earlobe,” “lobe,” “tragus,” “cartilage,” “auricle,” “piercing,” “treatment,” “management,” “outcome,” “keloid,” “aetiology,” and “etiology.” Boolean operators were used to integrate the search terms. The search protocol is summarized in the search strategy outline and PRISMA flow diagram¹⁰⁾ (Figure 1 and 2).

Figure 1.

Formal search strategy for studies investigating the pathology and treatment of keloid scars of the ear.

Figure 2.

PRISMA flow diagram detailing the formal search strategy and study selection.

PRISMA: Preferred Reporting Items for Systematic reviews and Meta-Analyses

The following key study types were retrieved: randomized controlled trials, cohort studies, case-control studies, and case series. Both independent reviewers screened titles and abstracts for overall eligibility and inclusion, then subsequently screened full papers for inclusion.

Inclusion

English language studies published within the last 10 years that focused on keloid scars affecting the ears and the treatment modalities associated with them were included. Additionally, all studies that discussed piercings as a cause of ear keloids met the inclusion criteria.

Exclusion

Studies that did not focus on ear keloids or were not published or translated into the English language were excluded. Single case studies, reviews, commentaries, and opinion pieces were also excluded.

Data extraction

A pre-specified Excel document was used for data extraction. The population of interest was patients with ear keloids undergoing treatment. The intervention and comparators were the treatment modalities, including surgery, compression therapy, steroid injection, radiotherapy, “other” or combined treatments. Outcomes of interest were complications, recurrence rates, challenges of treatment, scenarios where multiple treatment modalities are applied to a single session (outcomes of combined treatments), and relevant considerations made for specific piercing pathophysiology. Themes were extracted from each paper to facilitate thematic analysis and narrative synthesis. Table 1^11-35) contains characteristics of all studies based on this extraction.

Table 1.

Study Characteristics.

Author (year)	Type of paper	Number of subjects	Number of keloids	Gender	Average age	Number caused by piercings	Average Follow-up (months)	Recurrence %	Complications
Aljodah et al.11)	Cohort Study	41	52	41F	29	Not mentioned	13.0	9.6%	None mentioned
De Sousa et al.12)	Cohort Study	10	22	1M 9F	23.2	11	12.0	9.1%	Gastritis (n = 1), bleeding (n = 2), pigmentation (n = 2)
Nishat et al.13)	Cohort Study	78	78	Not Specified	32	Not mentioned	12.0	0% (compression) vs 10.3% (control)	Poor cosmesis (n = 9)
Ogawa et al.14)	Cohort Study	57	63	5M 52F	Not Specified	Not mentioned	18.0	0% (intralesional excision) vs 8.1% (simple excision)	No complications
Park et al.15)	Cohort Study	70	76	76F	Not Specified	76	18.0	9.2%	None mentioned
Tanaydin et al.16)	Cohort Study	88	88	29M 59F	24	38	78.0	29.5%	Discomfort (n = 40), pruritus (n = 9), skin irritation (n = 22), pressure sore (n = 8)
Thierauf et al.17)	Cohort Study	38	38	16M 22F	27	20	48.0	30.0%	None mentioned
Litrowski et al.18)	Cohort Study	66	97	33M 33F	20	46	24.0	36.0%	None mentioned
Tripoli et al.19)	Cohort Study	18	27	10M 8F	36	10	24.0	0.0%	None mentioned
Kanjoor et al.20)	Cohort Study	71	106	6M 65F	24.8	Not mentioned	6.0	5.6%	None mentioned
Cherry et al.21)	Cohort Study	22	26	9M 13F	9.7	Not mentioned	61.2	16.4%	Maceration (n = 1), necrosis (n = 4)
Domenico et al.22)	Case series	52	52	36 M 16F	38.6	Not mentioned	18.0	10.7%	None mentioned
Han et al.23)	Case series	17	23	3M 14F	Not Specified	17	9.0	8.7%	None mentioned
Khan et al.24)	Case series	94	135	49F 45M	14	135	24.0	28.7%	None mentioned
Kim et al.7)	Case Series	36	40	Not Specified	Not Specified	Not mentioned	24.0	10.0%	None mentioned
Maeda et al.25)	Case Series	3	3	3F	Not Specified	Not mentioned	80.7	0.0%	No complications
Mohammadi et al.26)	Case Series	21	31	21F	24.29	21	15.9	0.0%	None mentioned
Piccolo et al.27) (2022)	Case Series	80	83	Not Specified	Not Specified	Not mentioned	42.0	12.0%	None mentioned
Ramesh & Mohan28) (2018)	Case series	22	26	Not Specified	Not Specified	26	18.0	9.1%	None mentioned
Yang et al.29)	Case Series	21	21	Not Specified	Not Specified	1	36.0	0.0%	None mentioned
Agbomhekhe Ogah30)	Case series	7	12	1M 6F	28.1	10	6.0	8.3%	None mentioned
Lee et al.31)	Case series	24	24	4M 20F	25.3	19	12.0	38.0%	None mentioned
Kumar32)	Case series	5	5	Not Specified	Not Specified	Not mentioned	24.0	0.0%	None mentioned
Burusapat et al.33)	Randomized Controlled Trial	34	34	10M 24F	25	32	6.0	22.2% (immediate) vs 56.25% (delayed)	None mentioned
Khalid et al.34)	Randomized Controlled Trial	60	60	16M 44F	32	42	20.0	26.7% (5-FU/TAC) vs 56.7% (radiation)	wound dehiscence(n = 2), erythema (n = 2)
Sundfeld et al.35)	Randomized Controlled Trial	73	77	41M 32F	24.4	68	22.0	76% (flap) vs 40% (simple excision)	None mentioned

5-FU: 5-fluorouracil; F: female; M: male; TAC: Triamcinolone Acetonide

Bias and quality assessment

Each study was reviewed independently by two authors for risk of bias (RoB) and overall study quality, and results compiled. Due to the heterogeneous nature of the study types, three assessment scales were used to determine study quality. For both cohort studies and case-style studies, the Newcastle-Ottawa Tool (NOT) and SANRA were used to ascertain the selection, comparability, outcome, and study quality^36,37). The results from the NOT were translated into the Agency for Healthcare Research and Quality (AHRQ) scores³⁸⁾. Randomized controlled trials were assessed for bias using the Cochrane Risk of Bias 2 (RoB2) Tool³⁹⁾.

Results

Literature search

A systematic literature search yielded 120 total results. Following the removal of duplicates and the screening of abstracts, a further 58 papers were excluded. An additional 36 papers were removed following a full-text review. Twenty-six papers were included in the final review (Table 1, Figure 2)^11-33).

In total, 1,117 patients were included with 1,299 ear keloids (n = 572 explicitly stated to be caused by ear piercings, the remaining were either unknown or not stated) from three randomized controlled trials^33-35), 12 case series^7,22-32), and 11 cohort studies^11-21). Both adult and pediatric patients were included, with the average age being 25.7 years across both age groups (n = 8 for those whose age was “not specified”). The breakdown of gender for participants was omitted in six studies^{7,13,27-29,32)}.

Treatment modalities and complications

A breakdown of the treatment modalities provided for ear keloids in the literature is listed in Table 2 and 3. A variety of surgical approaches as the primary treatment modality to manage ear keloids are described in their respective studies (n = 959), with different techniques specified in their methodologies, as shown in Table 2^11-18,20-35). The predominant approaches were simple excision (60.8%), intralesional excision (22.0%), and fillet flap (10.4%). Other approaches included advancement flaps (0.3%)²⁵⁾ and triple surgical technique (ABC technique―arcuate incision, blind dissection, and core serial shave excision) (2.4%)²³⁾. While it is generally accepted that adjuvant treatment forms a part of the treatment pathway of keloid scars, two studies included surgery alone as a comparative limb^13,19).

Table 2.

Specified Surgical Approaches to Ear Keloid Scars.

Specified surgical technique	N
Simple excision	583
Intralesional excision	211
Fillet flap	100
Radical excision	27
Triple surgical technique (ABC)	23
Low-tension wound closure	12
Advancement flap	3

ABC: arcuate incision, blind dissection, and core serial shave excision

Table 3.

Specified Adjuvant Treatment for Ear Keloid Scars.

Specified adjuvant treatment	N
Topical treatments	486
Steroid injections	285
Radiotherapy	225
CO2 laser	135
Cryosurgery	97
5-Fluorouracil injections	30
Oral tranilast	24

CO₂: carbon dioxide

The variety of adjuvant therapy given either peri-operatively, post-operatively, or independent of surgery varied considerably between the literature (n = 1,282) (Table 3). The predominant adjuvant treatments included: topical treatments (including compression dressings and silicone gel) (37.9%), steroid injections (pre-operative, intra-operative, or post-operative) (22.2%), radiotherapy (17.6%), and cardon dioxide (CO₂) laser (10.5%). One study described combined triple therapy, which included surgical excision with a fillet flap, intralesional steroid injection, and topical treatments¹²⁾. Regarding the timing of steroid injections, two studies administered pre-operative steroid injections 4 weeks before surgical excision^11,33). Eight studies administered intra-operative steroid injections at the time of excision^{11,12,19,24,26,30,32,33)}. A further eight studies administered post-operative steroid injections^{11,17,19,20,26,30,32,33)}. Of these eight studies, the frequency of post-operative steroid treatments ranged from a one-off week one post-operative dose to weekly or monthly for up to 10 months^26,32,33). One study incorporated steroid injections as an adjunct at all three treatment windows (pre-operative, perioperative, and post-operative)¹¹⁾. Two studies described the use of CO₂ laser as a primary treatment without a surgical technique^22,27). Of these two studies, one used exclusively CO₂ lasers without describing any adjuvant topical treatment²⁷⁾.

Seven studies reported on post-treatment complications outside of recurrence of disease^{12-14,16,21,25,34)}. The overall complication rate was 37.2% (n = 102 reported complications, n = 274 patients in these seven studies), with most of these being generally accepted post-treatment complications. Pain was deemed the most common post-treatment complication (n = 40). However, other complications include skin irritation (n = 22), pruritis (n = 9), poor cosmesis (n = 9), pressure sore (n = 8), necrosis (n = 4), wound dehiscence (n = 2), erythema (n = 2), bleeding (n = 2), abnormal pigmentation (n = 2), maceration (n = 1) and gastritis (n = 1). Where a patient was reported to develop gastritis, this was considered a result of their post-operative steroid treatment, which necessitated postponement of one dose¹²⁾. Two studies that monitored post-treatment complications reported that all their patients had none^14,25).

Piercings

Fifteen studies described piercings as a cause of either primary or recurrent ear keloid scars (n = 572)^{12,15-19,23,24,26,29-31,33-35)}. Two studies described the potential specific pathophysiology of keloid scars in relation to piercings as a mechanism of injury^15,28).

Recurrence and follow-up

All 26 studies reported recurrence of disease, with an average recurrence rate of 20.3%^7,11-35). Five studies compared two treatment modalities and their recurrence rates^13,14,33-35), with reported recurrence ranging from 0%-76%^13,35). The recurrence rate for each study was compared against the reported planned follow-up for each patient. All 26 studies reported their variety of timelines for follow-ups, between 6 months and 6 years, with the average follow-up period being 25.8 months^7,11-35).

Quality assessment

The average SANRA sumscore for the cohort studies and case series was 5.7, which constituted fair quality of study selection (Table 4). Using the NOT, 14 studies had a fair AHRQ rating, six were good, and three were poor (Table 5). Using the Cochrane RoB2 Tool (Table 6), two randomized controlled trials were deemed to have “high” risk of study bias^31,35), whereas the third had “some concerns”³⁴⁾.

Table 4.

SANRA Scores for Cohort Studies and Case Series.

Author (year)	Justification for articles importance for readership	Statement of concrete aims or formulation of questions	Description of literature search	Referencing	Scientific reasoning	Appropriate presentation of data	Sumscore
Aljodah et al.11)	1	2	2	2	1	1	9
De Sousa et al.12)	1	2	1	1	1	1	7
Nishat et al.13)	0	1	0	1	1	0	3
Ogawa et al.14)	1	1	0	1	1	1	5
Park et al.15)	1	1	1	1	1	1	6
Tanaydin et al.16)	1	1	0	1	1	1	5
Thierauf et al.17)	1	1	0	1	1	1	5
Litrowski et al.18)	1	1	0	1	1	1	5
Tripoli et al.19)	1	0	1	1	1	1	5
Kanjoor et al.20)	1	1	2	1	1	1	7
Cherry et al.21)	1	0	1	1	1	1	5
Domenico et al.22)	1	1	2	2	1	1	8
Han et al.23)	1	1	1	1	1	1	6
Khan et al.24)	1	1	1	1	1	1	6
Kim et al.7)	1	0	0	1	1	1	4
Maeda et al.25)	1	0	0	1	1	0	3
Mohammadi et al.26)	1	1	1	1	1	1	6
Piccolo et al.27) (2022)	1	1	1	1	1	1	6
Ramesh and Mohan28) (2018)	1	1	1	1	1	1	6
Yang et al.29)	1	1	1	1	1	1	6
Agbomhekhe Ogah30)	0	1	1	1	1	0	4
Lee et al.31)	1	1	1	1	1	1	6
Kumar32)	1	1	0	1	1	1	5

SANRA: Scale for Assessment of Narrative Review Articles

Table 5.

Newcastle-Ottawa Scores and AHRQ Classification.

Author (year)	Selection	Comparability	Outcomes	AHRQ rating
Aljodah et al.11)	2	1	3	Fair
De Sousa et al.12)	0	2	3	Fair
Nishat et al.13)	2	1	1	Fair
Ogawa et al.14)	2	2	3	Good
Park et al.15)	1	0	2	Fair
Tanaydin et al.16)	2	1	3	Good
Thierauf et al.17)	2	2	2	Good
Litrowski et al.18)	3	1	1	Fair
Tripoli et al.19)	1	2	2	Fair
Kanjoor et al.20)	2	1	3	Good
Cherry et al.21)	0	0	3	Fair
Domenico et al.22)	1	1	1	Fair
Han et al.23)	2	1	0	Fair
Khan et al.24)	2	1	1	Fair
Kim et al.7)	3	1	3	Good
Maeda et al.25)	1	0	1	Poor
Mohammadi et al.26)	2	0	1	Fair
Piccolo et al.27) (2022)	2	0	1	Fair
Ramesh and Mohan28) (2018)	2	0	1	Fair
Yang et al.29)	2	2	2	Good
Agbomhekhe Ogah30)	2	0	0	Poor
Lee et al.31)	2	0	1	Fair
Kumar32)	1	0	1	Poor

AHRQ: Agency for Healthcare Research and Quality

Table 6.

RoB2 Scores for Bias for RCTs.

Author (year)	Type of paper	Outcomes	Randomization process	Deviation from intended interventions	Missing outcome data	Measurement of the outcome	Selection of the reported result	Overall bias
			1.0 Algorithm result	2.0 Algorithm result	3.0 Algorithm result	4.0 Algorithm result	5.0 Algorithm result	Assessor’s overall judgment
Burusapat et al.33)	Prospective Randomized Controlled Trial	Recurrence rate	Low	Low	Low	Low	High	High
Khalid et al.34)	Randomized Controlled Trial	Recurrence rate	Low	Low	Low	Low	Some concerns	Some concerns
Sundfeld et al.35)	Prospective Randomized Controlled Trial	Recurrence rate	Low	High	Some concerns	Low	Some concerns	High

RCT: randomized controlled trial

Discussion

Summary of findings

This present study serves as an up-to-date review of current considerations and approaches to managing keloid scars of the ear. As is consistent with previous literature reviews of keloid scars from all anatomical locations, the treatment modalities evaluated in the 26 eligible studies were widely heterogeneous⁸⁾. While most (88%) included surgical excision as a treatment arm, the specific surgical procedure varied from simple excision to intralesional excision or a flap-technique. Twenty-three studies that evaluated surgical excision of keloids included a peri-operative adjuvant therapy. While this is widely accepted as necessary to minimize risk of recurrence, the specific adjuvant therapy used was also highly variable. In most studies, the primary outcome of interest was recurrence rate, with successful treatment frequently defined as freedom from recurrence. Rates of recurrence varied with study size, follow-up period, and treatment strategy. The overall mean rate of recurrence was 20.3%. For the 23 studies involving surgical repair followed by adjuvant therapy, the average rate of recurrence was 19.4%. Both are consistent with the current accepted standards for keloid scars across all anatomical locations^8,40,41).

Treatment Modalities

Surgical options

When supplemented with preventive adjuvant therapy, surgical management of keloid scars provides an effective treatment strategy for the treatment of ear keloids. The most common surgical technique across all studies was simple excision, in which the entirety of the keloid scar is excised. This technique is an adequate option, provided the keloids are small enough to allow for primary tension-free wound closure. Litrowski et al.¹⁸⁾ (2014) describe keloid excision followed by immediate application of cryotherapy following complete or partial wider excision of 97 large ear keloids. A partial excision was conducted where complete excision would have resulted in significant deformity of the ear (n = 23). The recurrence rate was 36%; complications were few and limited to transient sensory symptoms. It is possible that the inclusion of only recurrent or long-lasting keloids may have contributed to the higher rate of recurrence in this study. As such, until more research on this modality has been conducted, it is difficult to say how promising this technique may ultimately become. Other reports of large ear keloids in the literature have described the following surgical techniques for management.

Intralesional keloid excision tends to be utilized in cases where the size or location of the ear keloid will likely result in aesthetic compromise or will not permit tension-free primary closure. In these cases, the keloid scar is surgically debulked, while the peripheral fibrotic borders of the scar are preserved. Provided appropriate adjuvant therapy is used, this has been shown to lead to similar rates of recurrence to complete excision^14,26,29,34).

The keloid fillet flap is a relatively novel technique, involving the removal of the bulk of the keloid and the creation of a flap from the superficial-most layer of scar tissue. This provides another option for large, bulky keloids in which wound tension is likely to prevent primary closure. This technique aims to create a flattened lesion to which adjuvant therapy can be applied, and when used for large keloids, has in many cases been shown to be superior to other surgical techniques^12,17,23,31). One study described a novel surgical approach in three patients with large ear keloids, using a chondrocutaneous bilateral advancement flap, comparable to an Antia-Buch technique²⁵⁾. While the authors report no evidence of recurrence after an average of 80.7 months, further study is required before inferences can be drawn regarding its efficacy.

Adjuvant therapy

While adjuvant therapy was utilized in almost all studies, the method and timing were widely variable. Intralesional steroid injections are considered to be an effective adjunct to surgical management of keloids through suppression of the inflammatory response, which is thought to be the basis of keloid formation. Two randomized controlled trials have investigated the benefits of intralesional triamcinolone acetate (TA) injection as an adjunct to surgery for the treatment of ear keloids^33,34). Khalid et al.³⁴⁾ (2018) found the injection of TA combined with 5-FU to be superior to electron-beam radiotherapy in minimizing the incidence of recurrence, with similar safety profiles (dosage: 150 mg 5-FU mixed with 0.2 ml/cm² TA). When surgery is combined with TA injections (either pre-operative, intra-operative, post-operative, or all three treatment windows), rates of recurrence across all non-trial studies varied from 0%-9.6%, with studies involving at least three injections faring better (pre-operative, perioperative, and post-operative)^{11,12,17,19,26,27,30,32)}. Outcomes were similar when limited to piercing-specific keloids. The timing of injection was heterogeneous across studies, although it mostly involved intra-operative or immediate post-operative injection. A randomized controlled trial performed by Burusapat et al.³³⁾ (2021) found immediate intra-operative TA injections (dosage: 0.1-0.2 ml to 10 mg/ml) to be significantly more effective at reducing recurrence risk when compared to delayed injections at 1 week post-surgery. Complication rates were low and were either surgery-related (wound dehiscence) or minor skin changes such as hypopigmentation.

Compression therapy involves applying mechanical pressure to the keloid site with the aim of reducing blood flow and therefore fibroblast activity and collagen lay-down⁷⁾. Ear clips or magnets are used to apply pressure, which in many cases are specifically designed to cater for the range of different keloid wound sites and sizes. The obvious challenge of ear discomfort when wearing the pressure device is difficult to overcome and was present across most studies incorporating compression therapy. Cherry et al.²¹⁾ (2021) reported this challenge to be enhanced in cases of bilateral keloids, in which to minimize discomfort, pressure clips were alternated. This resulted in higher rates of recurrence. As an adjunct to surgery, this technique avoids steroid-related complications, although recurrence rates were higher in many cases (0%-29.5%)^{7,13,15-17,21,30,31)}.

Electron-beam radiotherapy used in isolation for ear keloids is considered to have a high recurrence rate and is controversial; however, when used as an adjunct to surgical excision may be a useful treatment modality^14,34). The average treatment regimen was three doses over 3 days. The range of total doses of each regime varied from 10-20 Gy (average = 13 Gy). Apart from a 56.7% recurrence rate in the trial conducted by Khalid et al.³⁴⁾, recurrence across the literature did not exceed 8.7% when radiotherapy was employed as an adjunct. When appropriate measures are taken, adverse effects appear to be limited to redness of the target area, with cancer risk being reported as very low^{14,23-25,29,42)}. Two studies described the use of radiotherapy in primary keloid scars (n = 66)^14,35). Six studies described the use of adjunctive radiotherapy in both primary cases of keloid scars and recurrent keloids (n = 159)^{23-25,29,35,42)}. Of these studies, none highlighted the difference in outcomes in adjunctive radiotherapy in primary versus recurrent keloid groups. Furthermore, no studies included in this review described the use of radiotherapy exclusively on patients presenting with recurrent keloids. Cryotherapy was utilized in a single study, although recurrence was higher (36%) due to the inclusion only of recurrent or long-lasting keloids¹⁸⁾.

Combined therapy was utilized in three studies^12,30,31). De Sousa et al.¹²⁾ (2014) describe the use of intra-operative TA injection and silicone sheet application as “triple therapy” on 22 keloids, with an overall recurrence rate of 9.1%. A similar recurrence rate of 8.3% was found with a combination of steroid injections and pressure therapy, although this study investigated only 12 keloids and had a poor SANRA score³⁰⁾. Finally, a case series of fillet flap procedures followed by pressure dressings and silicone gel by Lee et al.³¹⁾ (2024) saw a higher recurrence rate of 38%. This brings some doubt as to whether the risk of side effects with combination therapy provides justifiable long-term benefits.

Fractional CO₂ laser (with a combined pulsed dye laser [PDL]) as a primary treatment strategy was investigated in two case series, with adjunctive compression therapy only present in one^22,27). Piccolo et al.²⁷⁾ (2022) described a regime where two groups of patients (n = 83) received a single fractional CO₂ laser followed by a single immediate PDL treatment. The first group did not have any further treatment (n = 40), whereas the second group (n = 43) was offered a further immediate Enerjet (jet volumetric remodeling) treatment. Domenico et al.²²⁾ (2023) also integrated immediate fractional CO₂ laser followed by immediate PDL treatment for ear keloids in a single session. Additionally, patients were given a single immediate EmoLED (blue light LED emission treatment) followed by 2 weeks of compression as an adjunct. In both studies, patients whose keloids were greater than 2.5 cm were also offered an additional adjunct PDL 40 days before the primary CO₂ laser treatment. This was with the view to impact vascularity and stimulate VEGF cytokines, to soften and “prepare” the keloids for treatment. Overall, both studies reported good recurrence rates (11.5% vs 10.7%), which are comparable to those of surgical excision followed by adjunctive therapy. While there appears to be some demonstrable benefit of CO₂ laser for ear keloids, there may be a greater benefit of combined CO₂ laser treatment and PDL in comparison to monotherapy. The demonstrable efficacy of a third adjunctive treatment, such as Enerjet or EmoLED, is less clear in these studies. Additionally, neither paper discussed the use of topical steroids, which is a common adjunct following laser treatment. The anti-inflammatory properties of topical steroids may limit the initial inflammatory response to laser treatment, and there is scope to consider its benefit in keloid treatment⁴³⁾. Furthermore, CO₂ laser treatment has limited reliability due to high costs, limited availability of laser devices in many units, and significant dependence on operator experience.

The pathophysiology of piercings

Many studies failed to report the etiology of their keloids, and many of those that did, did not provide results specific to those that were piercing-induced. Ramesh and Mohan²⁸⁾ (2018) based their surgical approach on a theoretical understanding of the pathophysiology of piercing-induced keloids. Cha et al.⁴⁴⁾ (2013) previously described the presence of a sinus tract associated with piercing-induced keloids. The tract develops because of an inflammatory response to trauma and foreign bodies introduced by ear piercing. This penetrating injury connects scarred tissue on either side of the ear. They proposed that if part of the tract is left in situ, it can become a cause of keloid relapse. Ramesh and Mohan²⁸⁾ (2018) highlighted the importance of ensuring all the tract is removed, especially in cases where scarring only appears to exist on a single side of the ear. Loupe magnification is utilized, both ensuring all tract is removed and maximizing the extent of remaining healthy tissue. Results of this case series demonstrated freedom from recurrence in 90.9%, although investigation with more rigorous methodology is required to evidence whether this approach can improve outcomes.

In studies that did report outcomes for piercing-induced ear keloids, the method of keloid induction did not appear to impact outcomes^{7,13,15,21,23,26,28,30-32)}. Instead, the predominant factors in determining outcomes within such studies were keloid size, previous recurrence, and family history. It should also be noted that these studies also specified that ear lobes had the highest rates of keloid formation in comparison to other anatomical zones of the ear, such as the helical rim. They did not specify why this may be the case, although it can be inferred that cultural use of piercings is most frequently inserted in earlobes compared to other zones of the ear^{7,13,15,21,23,26,28,30-32)}.

Limitations

The present work aimed to evaluate the current management options for keloids of the ear, as well as the pathophysiology and role of piercing as a cause. However, this study has some notable limitations. First, while limited only to keloids of the ear, the included studies were heterogenous about keloid location (lobe vs helix), size, previous recurrence, patient demographic, and follow-up period. This explains the high variability of recurrence rates across the literature, and makes direct comparison of recurrence rates potentially misleading. Although a significant portion of patients with ear keloids were caused primarily by piercings, where no cause was described, it was assumed these were caused at least secondarily due to piercings. Furthermore, management protocols even for the same method of treatment were varied. These factors rendered statistical analysis of results inappropriate, meaning no definitive conclusions can be drawn regarding relative treatment efficacies. Study quality was assessed as being “low” to “moderate” in most cases by our RoB tools, highlighted further by all but one of the included studies having less than 100 patients. This demonstrates the paucity of available high-quality evidence to guide optimal treatment and hinders result interpretation. Additionally, outcomes of interest were limited to recurrence rates and complications, and this review does not take into account other important measures such as cost-effectiveness and accessibility. It is worth noting that certain novel treatments, such as CO₂ laser treatment, are likely expensive and inaccessible for most centers treating keloid scars.

Two reviews have been conducted recently that highlighted similar outcomes. Anderson et al.⁴⁵⁾ (2021) highlighted the variety of strategies that may be utilized in conjunction with surgical excision, with particular emphasis on intralesional steroid injections, 5-FU, and laser therapy for reducing recurrence rates. However, they focused on keloid scars across the entire human body, and it has been highlighted in our review that ear keloids may act differently, both through their etiology (piercings as the most common cause) and pathophysiology. Tahir et al.⁴⁶⁾ conducted a review and meta-analysis on compression therapy following surgical excision of keloids. They concluded that post-operative compression therapy, such as silicone gel and compressive earrings, has a place in reducing recurrence rates, although they admitted that more research is required, as there is no “single-best” compressive treatment available⁴⁶⁾.

Finally, this review's search strategy was limited to English (or those which had been translated to English). This potentially disregards numerous studies in Asian and African countries, in which keloid incidence is notably higher.

Conclusions

Various treatment options exist for the management of ear keloids, with no single optimal treatment strategy having yet been identified. Evidence suggests that surgery combined with a single therapeutic adjunct can result in favorable outcomes, even in cases of previously recurrent or long-lasting keloids. Surgical strategy should be tailored to each case, considering the keloid's size, location, and shape to ensure proper wound healing. However, alternative treatment modalities such as CO₂ laser should also be considered as a potential treatment option. As with surgical therapy, CO₂ laser is best utilized in conjunction with an additional treatment of PDL. Adjunctive treatment strategies have not yet been directly compared in high-quality large-scale research. Based on the available body of evidence, intralesional steroid injection, compression therapy, and electron-beam radiotherapy are all feasible options, and decisions should continue to be made with consideration of patient preference. The evidence for utilizing further novel treatments in addition to CO₂ laser, such as Enerjet, is poor thus far, with more research at larger scale and other centers to demonstrate transferability and accessibility. The current evidence base would benefit from the direct comparison of adjunctive therapies to be given alongside surgery in a larger randomized controlled trial. Furthermore, a direct comparison between CO₂ laser treatment and surgical therapy (with adjunctive treatment) in a large single center that conducts these treatments would highlight outcomes on the same patient population group. There is additional scope to consider the integration of post-treatment topical steroids and then monitor patient outcomes, including adverse effects. Although this study did not focus on patient-reported outcome measures, there is scope to focus on patient perspectives on their outcomes of treatment, keloid scars, especially recurrent scars, can significantly impact patient quality of life. Finally, given that most keloid scars of the ear are a result of piercing, future studies should consider the role played by the pathophysiological scarring pattern specific to piercing-induced keloids. Addressing this when managing ear keloids may well further improve outcomes.

Author Contributions: HH and LD contributed equally to the article and have submitted for joint first authorship. HH designed the study. HH and LD conducted the literature review and completed each element of the manuscript. LD provided edits to the manuscript feedback. BD was supervisor for this manuscript and provided amendments to the draft.

Conflicts of Interest: There are no conflicts of interest.

Ethical Approval: No ethical approval was required for this review article.

Consent to Participate: No patient consent was required for this review article.

Consent for Publication: No patient/participant consent was required to publish this review article.