Advances in the treatment of axillary bromhidrosis

Abstract

Background

Bromhidrosis, characterized by foul‐smelling sweat, is a prevalent condition that significantly affects patients' social and psychological well‐being.

Methods

This review presents novel treatment approaches and discusses the pros and cons of various treatment options for axillary bromhidrosis.

Results

Extensive research has explored numerous treatment modalities for bromhidrosis. This article systematically reviews both surgical and nonsurgical interventions utilized in clinical practice.

Conclusion

By synthesizing available evidence, this review aims to offer evidence‐based recommendations for effectively managing bromhidrosis, considering factors such as treatment efficacy, safety profiles, patient preferences, and clinical outcomes.

1. INTRODUCTION

Bromhidrosis is thought to result from the degradation of unsaturated branched‐chain fatty acids excreted by the apocrine sweat glands located in the axilla, leading to a distinctive odor when metabolized by bacteria present on the skin in the axillary region. Patients with bromhidrosis typically exhibit an increased number and volume of sweat gland tissue in the axillae compared to individuals without this condition. The enlarged glandular cavities contain a higher number of secretory cells, resulting in an elevated secretion of sweat. According to surveys, the prevalence of bromhidrosis in Chinese individuals is 6%, in contrast to rates as high as 90% among Caucasians and 99.5% among individuals of African descent. ¹ The management options for bromhidrosis encompass a range of modalities, including local medications, injection therapy, phototherapy, and other physical interventions, as well as surgical procedures. While the field of bromhidrosis treatment continues to evolve with the introduction of new clinical approaches, each method presents its own set of advantages and limitations. This article aims to offer a comprehensive and systematic review of both surgical and nonsurgical treatments for bromhidrosis in clinical practice, outlining the strengths and weaknesses of each approach to guide clinicians in the optimal management of this condition.

1.1. The pathogenesis and treatment principles of bromhidrosis

The axilla harbors a substantial number of apocrine sweat glands, with the sweat initially secreted by these glands being sterile. However, upon interaction with microorganisms like Clostridium perfringens, the organic components in the sweat undergo decomposition, giving rise to the production of short‐chain fatty acids and ammonia, which impart a distinct odor characteristic of bromhidrosis. Furthermore, ongoing research into bromhidrosis has revealed the crucial role of the ABCC11 (MRP8) gene in its pathogenesis. ABCC11 has been identified as being expressed and localized within the sweat gland, and a common single‐nucleotide polymorphism (SNP) known as 538G‐A, prevalent in Asians, has been associated with the almost complete absence of the typical odorous compounds in axillary sweat. ² The current approach to treating bromhidrosis primarily involves the removal of apocrine sweat glands, inhibition of sweat secretion, and suppression of bacterial growth. These treatment methods can be broadly categorized into non‐surgical and surgical interventions.

Some people experience increased sweating due to physical illnesses, a condition known as secondary bromhidrosis, such as hyperthyroidism, endocrine disorders, mental illnesses, and hormonal imbalances during menopause. And primary bromhidrosis is characterized by excessive sweating caused by overactive sympathetic nerves rather than by an underlying illness, medically referred to as primary bromhidrosis. The diagnostic criteria for bromhidrosis are generally divided into level 0, level 1, level 2, level 3, etc. (Table 1).

TABLE 1.

Diagnostic grading of bromhidrosis.

Level 0	Fox odor is mainly caused by excessive secretion of sweat glands, which prevents sweat from evaporating but does not produce an unpleasant odor.
Level 1	Level 1 Fox odor usually has mild symptoms, mainly due to the pungent odor emanating from the armpits after physical labor or vigorous exercise, which can generally be smelled by oneself.
Level 2	The second level sheath is moderate and is generally prone to emitting a strong fox odor in the armpit area after completing daily activities, which can be smelled in close proximity.
Level 3	The symptoms of Level 3 body odor are quite serious, usually when there is no activity or physical labor, the armpits will also emit a pungent odor.

For patients presenting with mild bromhidrosis (levels 0 and 1), pharmacological or injection therapies are considered viable options, given their cost‐effectiveness and significant efficacy. In cases of moderate bromhidrosis (level 2), laser treatments or surgical interventions are recommended, as these methods can yield satisfactory outcomes. For severe bromhidrosis (level 3), surgical therapy is advised to eradicate the subcutaneous sweat glands and associated glandular tissues in the axillary region, aiming for a definitive resolution of the condition. The subsequent sections will detail the advantages and disadvantages associated with each treatment modality.

1.2. Non‐surgical treatment of bromhidrosis

1.2.1. Topical application

This method is economical and convenient, offering minimal discomfort and a lower risk of complications and side effects associated with surgical interventions, thus enhancing patient acceptance. It is primarily appropriate for patients experiencing excessive sweating or mild odor. However, it proves ineffective for those with moderate to severe conditions, and prolonged usage may lead to skin irritation and other issues. Importantly, topical medications do not provide a cure for bromhidrosis. The mechanisms through which current medications address bromhidrosis are outlined in Table 2.

TABLE 2.

Topical medication.

Topical medication	Therapeutic mechanism	Advantage	Disadvantage	Radical treatment?
Deodorants	Reduces the effect of fatty acid odorants.	Convenient and cheap, high comfort.	Long‐term use will cause skin irritation and other problems.	NO
Fragrance	Eliminate or mask undesirable odors, or change malodors into pleasant smells.
Antimicrobials or fungicides	Inhibit the growth of pathogenic bacteria that produce body odor.
Antiperspirants	Inhibit the discharge of sweat.
Hormonal modulators	Probably by interfering with the secretion of lipoproteins or androgens, leading to a decrease in the concentration of malodorous substances.

1.2.2. Deodorants

Deodorants are a common class of topically applied drugs that work by neutralizing and reducing the impact of odorous fatty acids, effectively eliminating unwanted odors. ³ , ⁴ Takeshi et al. developed a white activated carbon with enhanced adsorption capacity for body odor compounds and demonstrated its ability to effectively reduce armpit odor. However, the limited accessibility of this product is attributed to the complexities involved in its production process. ⁵ However, it is still not widely used due to the production process.

1.2.3. Fragrances

Fragrances are chemicals that either neutralize or obscure unpleasant odors, or transform foul odors into more desirable scents. Nevertheless, deodorant products containing artificial fragrances have been linked to allergic reactions and may have adverse effects on skin well‐being. ⁶ Lam et al. conducted a prospective trial to assess the efficacy of lemon in treating bromhidrosis. While lemon exhibited odor‐masking properties and acid‐base neutralization effects that could mitigate the odor caused by certain amines, some patients experienced localized skin irritation as a potential adverse reaction. ⁷

1.2.4. Antimicrobials or fungicides

Antimicrobials or fungicides primarily act to inhibit or eradicate the growth of pathogenic bacteria responsible for body odor production, for example, trichlorodiphenylurea and copper zinc pyrithione. ⁸ However, these antibacterial agents not only target harmful bacteria but also disrupt the growth of normal skin flora, thereby perturbing the delicate microbial balance of the skin. ⁹ Recent studies have highlighted the symbiotic relationship between the skin and its flora, where the skin provides a conducive environment for flora to thrive, and the physiological activities of skin flora contribute to barrier protection. As understanding of the skin microbiota increases, there is growing interest in novel antimicrobial actives that selectively regulate the growth of skin flora, specifically targeting major odor‐causing species without disrupting resident skin bacteria. This approach aims to establish a healthier and more balanced skin flora, thereby promoting skin health. However, many novel antimicrobial actives are biofermented products, and their mechanisms of antimicrobial selectivity remain to be fully elucidated. ⁴

1.2.5. Antiperspirant

Antiperspirant drugs share a common mechanism of action, which involves inducing mechanical blockage of small secretory gland ducts. This leads to the atrophy of small secretory glandular vesicles, ultimately inhibiting the discharge of sweat and providing a deodorizing effect. Commonly used agents include aluminum oxide, aluminum chloride, and allantoin‐based compounds. ¹⁰ , ¹¹ , ¹² However, the acidity of metal salts can irritate the skin and lead to adverse reactions such as skin redness. In order to circumvent this issue, Lolla et al. developed a novel hygroscopic material, propylene glycol. This material facilitates the evaporation of sweat as it nears the sweat gland outlet, resulting in nearly complete dehydration of sweat. Additionally, it forms a natural gel‐like salt plug inside the sweat gland outlet, effectively blocking further sweat discharge. By utilizing this technique, the necessity for external metal salts to seal sweat ducts is eliminated, thus preventing the potential irritation caused by metal salts on the skin. ¹³ However, the material has a shorter duration of preventing sweat from draining.

1.2.6. Hormonal modulators

The secretory function of the apocrine sweat glands becomes evident only after the onset of puberty. Research has demonstrated the presence of androgen receptors in the secondary epithelial cells of the apocrine sweat glands, with higher concentrations observed in patients with bromhidrosis compared to those with normal levels. ¹⁴ This suggests a possible association between bromhidrosis and the presence of androgen receptors within the body. Gregoriou et al. conducted a study in which they applied a topical glycine‐soy steroid complex to successfully address bromhidrosis, potentially by modulating the secretion of lipoproteins or androgens, resulting in a reduction of malodorous compounds. ¹⁵ Research on the inhibition or eradication of bromhidrosis through hormone‐level regulation remains insufficient, necessitating further basic experiments and clinical trials to substantiate its potential application.

1.3. Injectable drug therapy

Drug injection therapy is considered a minimally invasive treatment option with a wide range of injectable drugs available for clinical use, particularly in China. However, the majority of these drugs lack substantial clinical trial data, with the exception of botulinum toxin type A. Hence, additional large‐scale clinical trials and fundamental research are necessary to validate the efficacy and safety of these injectables (Table 3).

TABLE 3.

Injectable drug therapy and oral drugs.

Injectable drug therapy	Therapeutic mechanism	Advantage	Disadvantage	Radical treatment?
Botulinum toxin type A	Block the acetylcholine‐mediated secretion of the exocrine and apocrine sweat gland.	Local injection of drugs is simpler than photoelectricity and surgery	Safety is affected by factors such as the type of drug and the level of injection. There is a wide variation in efficacy. The drugs that are recognized as safe and effective are few.	NO
Ethanol	By absorbing water in the surrounding tissues, it leads to aseptic inflammation, dehydration and necrosis of tissues.			YES
Other medications	Destroying the sweat glands or ducts.			NO/YES
Oral drugs	Mmainly based on anticholinergic drugs, which can inhibit the secretion of sweat by the glands.	Good treatment effect	Sserious side effects.	NO

1.3.1. Botulinum toxin type A

Botulinum toxin type A functions by inhibiting the release of acetylcholine from nerve axons at the neuromuscular junction, thereby impeding acetylcholine‐mediated secretion of the exocrine and apocrine sweat glands. Consequently, the utilization of botulinum toxin presents a rational therapeutic option for managing hyperhidrosis and bromhidrosis. ¹⁶ Utilizing botulinum toxin for managing hyperhidrosis and bromhidrosis represents a viable therapeutic avenue. Through intra‐dermal injection, a focal, reversible, and enduring chemical denervation can be attained. The resultant effect typically lasts for 6–9 months or even longer, manifesting in reduced sweating and bromhidrosis approximately 2–4 days post‐injection. This method has the characteristics of short surgical duration and relatively short onset time, and has been proven to be both convenient and effective. However, it should be noted that deodorization effects are not permanent, necessitating multiple injections for sustained benefit, thereby incurring higher costs over time. ¹⁷ He et al. administered botulinum toxin type A injections to 53 patients with secondary bromhidrosis, all of whom exhibited amelioration in bromhidrosis symptoms. These findings underscore botulinum toxin type A as a dependable option for secondary bromhidrosis management. ¹⁸ Furthermore, the initial low responsiveness to botulinum toxin type A treatment among bromhidrosis patients does not necessarily indicate a diminished response to long‐term therapy. ¹⁸

1.3.2. Anhydrous alcohol

Han et al. administered percutaneous ethanol injections to 165 patients diagnosed with bilateral bromhidrosis, with the majority demonstrating excellent or good outcomes at a follow‐up period of 14.5 months. ¹⁹ Asilian et al. conducted transdermal ethanol injections on 30 patients, with 50% of them experiencing significant improvements in outcomes ranging from good to excellent, all without encountering any serious complications. The discrepancies observed in the outcomes of these two trials could potentially be attributed to variances in the racial and ethnic profiles of the patient cohorts. By segmenting the axilla into three to four regions on average, this technique offers several advantages, including simplicity in execution, minimal invasiveness, absence of scarring, and swift recovery. Nonetheless, the use of anhydrous alcohol carries the risk of local skin necrosis if extravasation occurs, presenting challenges in controlling the depth of injection, and highlighting the limited clinical understanding of potential long‐term complications associated with this approach. ²⁰ Controlling the depth of injection poses a challenge, and there exists a lack of clinical data regarding potential long‐term complications.

1.3.3. Other medications

In China, various preparations such as hemorrhoid elimination injection, Chinese herbal medicine Paeoniflorin, and 5‐fluorouracil have been employed for local injections aimed at treating bromhidrosis by targeting sweat glands or ducts for destruction. Compared to phototherapy and surgical interventions, local drug injections offer a simpler approach; however, their safety profile is contingent upon factors such as the type of drugs used and the injection depth. The effectiveness of these treatments varies significantly, and some modalities deviate from standard protocols, leading to contentious safety concerns. Consequently, the utilization of such drug injections for bromhidrosis treatment remains limited, owing to the prevailing controversy surrounding their safety and efficacy.

1.4. Oral medication

The current oral medications utilized for treating bromhidrosis predominantly rely on anticholinergic drugs. These agents function by impeding sweat gland secretion, thereby proficiently alleviating bromhidrosis and hyperhidrosis. Notably, bromelain and oxybutynin represent the prevalent anticholinergic drugs employed for this purpose. Nevertheless, these medications frequently provoke a plethora of adverse reactions and contraindications, engendering widespread anticholinergic effects such as xerostomia, xerophthalmia, urinary retention, and cephalalgia. Moreover, discontinuation often results in relapse, posing challenges for patients in embracing prolonged pharmacotherapy. ²¹

1.5. Laser and others

It is currently widely accepted that the efficacy of laser treatment for armpit odor primarily stems from the photothermal effect induced by the laser. The laser output is absorbed by melanocytes, leading to a thermal effect that results in the destruction of local hair follicles, apocrine sweat glands, and surrounding tissues. This process renders these structures incapable of secretion, thereby effectively addressing armpit odor. Similarly, other treatments such as radiofrequency and microwave therapy predominantly operate by thermally destroying the apocrine sweat glands, thereby achieving their therapeutic effect (Table 4).

TABLE 4.

Phototherapy and other non‐surgical treatments.

	Therapeutic mechanism	Advantage	Disadvantage	Radical treatment?
Nd: YAG laser, CO2 laser and Semiconductor laser	Destruction of the sweat glands by photothermal action of laser light	Simple operation, less invasive short treatment time, fast postoperative recovery	Lack of targeting and selectivity for sweat glands, high recurrence rate, and high equipment requirements	YES
Radiofrequency technology	By resonating with the water molecules in the sweat gland tissue, heat is generated to destroy the sweat gland tissue
Microwave therapy	Using the heat energy of electromagnetic waves to selectively heat the moisture‐rich dermis and sweat glands
High‐frequency electroacupuncture	Tthrough the discharge of electrocoagulation to destroy the sweat gland tissue
β‐particle bromhidrosis treatment device	The release of β‐rays continuously destroys sweat glands
Ultrasonic emulsification aspiration	Use ultrasonic cavitation effect on the tissue to produce emulsification, fragmentation effect and negative pressure scraping and suction double destruction of sweat gland tissue and hair follicles

1.5.1. Nd: YAG (neodymium‐doped yttrium aluminum garnet) laser

Currently, two primary methods exist for treating bromhidrosis with Nd: YAG. The first method involves a non‐cutaneous approach, wherein local anesthesia is administered to the treatment area, followed by the configuration of working parameters. Subsequently, the fiber optic head is directed toward the hair follicle openings, and individual spots are cauterized to disrupt the functionality of the sweat glands. ²² The subcutaneous approach entails creating multiple puncture holes in the axillary periphery following tumescent anesthesia. A tonoplast or sharp separator is then utilized to carefully separate the deep dermis from the subcutaneous tissues through the puncture holes. Subsequently, a fiber optic is inserted directly into the subcutaneous layer via a 1–2 mm metal tube. The acromegaly glands are then cauterized directly beneath the skin to effectively treat bromhidrosis. ²³ , ²⁴ The aforementioned methods each possess distinct advantages and drawbacks. Lee et al. conducted a comparative study involving 1444 nm Nd:YAG laser treatment in the left axilla and a modified Inaba's method in the right axilla. ²⁵ The recovery from postoperative bruising and impaired movement was notably quicker in the left axilla. At the 12‐month postoperative mark, residual malodor in the left axilla was deemed “tolerable,” whereas in the right axilla, it was deemed “absent.” ²⁶ Piccolo et al. conducted a follow‐up study involving 24 patients who underwent treatment with the 1444 nm Nd: YAG laser for bromhidrosis. Six months postoperatively, bromhidrosis was evaluated as “absent” in 14 patients, “fair” in 9 patients, and “strong” in 1 patient. ²⁷

Youn et al. demonstrated that 1444 nm laser beam is stronger than 1064  and 1320 nm. This indicates that the wavelength of 1444 nm exhibits a more potent lipolytic effect, leading to increased efficiency and restricted thermal diffusion to surrounding tissues. Consequently, this wavelength enables more effective destruction of sweat glands in adipose tissue, with limited thermal impact on surrounding tissues. ²⁸

1.5.2. CO₂ laser

Currently, the most commonly utilized methods include CO₂ fractional mode or CO₂ super pulse mode. These methods involve treating the entire axillary hair area and expanding it appropriately by 1 cm. Axillary skin tissue and sweat gland tissue are rapidly vaporized in a fractional pattern. The treatment endpoint is standardized by the presence of yellow cloudy liquid or a burnt odor emanating from the holes. The CO₂ laser, with its higher peak energy, promptly vaporizes the superficial sweat gland tissue and penetrates deeper. ²⁹ However, this may result from deliberately leaving some sweat glands intact during treatment to mitigate potential complications.

1.5.3. Semiconductor laser

When irradiated in a 360‐degree manner, the device exhibits an expanded action range and provides a more uniform energy distribution, overcoming issues associated with traditional narrow‐angle laser irradiation and photothermal focusing. Specifically, the utilization of a 980 nm semiconductor laser for indirect photothermal action shows promising results in effectively targeting superficial subcutaneous fat tissue and sweat glands. Additionally, lasers with wavelengths of 810 , 980 , and 1440 nm demonstrate the capacity to heat water molecules. Of particular note, the 810  and 980 nm wavelength lasers exhibit the ability to penetrate the skin to a depth of approximately 1.5 mm, enabling the targeted elimination of superficial subcutaneous fat tissue and apocrine sweat glands in the axillary region while maintaining a high level of safety with minimal impact on the epidermis.

1.5.4. Radiofrequency technology

By resonating with water molecules present in sweat gland tissue, heat is generated, facilitating the destruction of said tissue, consequently addressing bromhidrosis. Li et al. conducted a comparative analysis between radiofrequency microneedling and surgical interventions, revealing no statistically significant difference in efficacy. However, patients subjected to high‐frequency electro‐acupuncture exhibited greater satisfaction levels 1‐month post‐surgery. Furthermore, the high‐frequency electro‐acupuncture group reported minimal complications, whereas the surgical group experienced two instances of bleeding‐related complications. ³⁰ Cho et al. investigated the comparative efficacy of long conduction time and low power versus short conduction time and high power in treating bromhidrosis across 10 pairs of split axillae. The findings revealed that the long conduction time and low power groups exhibited greater effectiveness. ³¹ The findings indicated that the long conduction time and low power groups were more effective. Radiofrequency technology for treating bromhidrosis is characterized by its simplicity, minimal contraindications, and low invasiveness. Patients may experience only erythema and slight bruising in the early postoperative period, with hyperpigmentation and mild numbness of the skin sensation in the operated area typically resolving in the short term. However, a notable disadvantage is the risk of recurrence, and research in this area remains limited.

1.5.5. Microwave therapy

Microwaves are electromagnetic signals characterized by frequencies ranging between 300 MHz and 300 GHz. Leveraging the heat energy inherent in electromagnetic waves, microwaves selectively target and heat the moisture‐rich dermis and sweat glands. Johnson et al. provided evidence indicating that microwave technology can effectively concentrate heat at the interface between the skin and subcutaneous tissue, a region coinciding with the distribution of sweat glands, irrespective of variations in skin thickness. ³² Consequently, it proves to be an effective remedy for bromhidrosis. Following Johnson's pioneering application of microwave technology in bromhidrosis treatment, numerous scholars have undertaken related clinical investigations. In a systematic review conducted by Hsu et al., encompassing five clinical trials involving 189 patients, the outcomes indicated that microwave treatment for axillary bromhidrosis offers sustained efficacy with minimal adverse effects. Additionally, the majority of patients expressed satisfaction with the outcomes of these studies. ³³ Specialized instrumentation and the associated high costs of treatment continue to pose significant constraints on the advancement of these therapeutic approaches. ³⁴ , ³⁵ , ³⁶ , ³⁷

1.5.6. High‐frequency electroacupuncture

High‐frequency electroacupuncture is applied to the sweat glands via the pores, utilizing electrocoagulation to destroy the sweat gland tissue and reduce sweat secretion, thereby effectively eliminating armpit odor and treating bromhidrosis. ³⁸ The efficacy of this treatment is directly dependent on the experience of the operator, with varying results and potential adverse reactions. While some scholars and small‐scale institutions continue to utilize this method, its use is declining as newer instruments and techniques emerge.

1.5.7. β‐particle bromhidrosis treatment device

The β‐rays emitted by the β‐particle bromhidrosis treatment device continuously target and radiate the sweat glands in the axilla, leading to the suppression of their secretion function. ³⁸ Due to the short‐range nature of β‐rays, the primary mechanism of action of the treatment apparatus is ionization damage, with minimal radiation exposure. With proper absorption levels, the surrounding skin is not at risk of radiation damage.

1.6. Surgical treatment of bromhidrosis

Surgical intervention stands as one of the foremost effective approaches in addressing bromhidrosis presently. Ongoing advancements in surgical techniques and equipment contribute to a reduction in postoperative complications associated with bromhidrosis. Nonetheless, it is not without its limitations. Lengthy postoperative recovery periods and the potential for specific complications unique to each surgical procedure are among its drawbacks (Table 5).

TABLE 5.

Surgical methods.

Surgical methods	Therapeutic mechanism	Advantage	Disadvantage	Radical treatment?
Local skin excision surgery	Surgical removal of the skin tissue where the sweat glands are located.	Effective treatment with low recurrence rate.	Long postoperative recovery time and each surgical procedure has its own postoperative complication.	YES
Radical resection with small incision and Small incision scratching	Surgery destroys sweat gland tissue under the skin but preserves the skin.
Liposuction and curettage	Using tumescent anesthesia with other instruments to destroy the sweat gland tissue under the skin.
Endoscopic‐assisted bromhidrosis treatment	Destruction of sweat gland tissue under the skin with the aid of an endoscope.
FUE hair follicle extraction technology application	Removal of hair follicles and sweat gland tissue using FUE technology.
Thoracic sympathectomy	Cutting off the sympathetic nerves and blocking sweat secretion.

1.6.1. Local skin excision surgery

The bilateral axillary hair areas are surgically treated by excising the skin and subcutaneous tissues in a shuttle shape. The depth of excision is above the superficial fascial layer of the axilla, ensuring complete removal of the apocrine sweat gland tissues. Subsequently, the wound edges are slightly separated subcutaneously and then meticulously sutured together. However, this technique may result in the formation of thread‐like scars postoperatively, and some patients may experience scar contracture and varying degrees of upper limb impairment due to tension or scarring.

To address these concerns, Z‐plasty can be employed to modify the scar's tension line, transforming a linear scar into an arc‐shaped scar. By altering the tension line of the scar, the occurrence of scar contracture deformity can be avoided, thus reducing its impact on upper limb function. Despite its effectiveness, the application of Z‐plasty has become less frequent in recent years due to concerns over the conspicuousness of large scars, which can adversely affect both the patient's appearance and upper limb activities. ³⁹

1.6.2. Radical excision with small incision

A small incision is made parallel to the axillary fold line in the center of the axilla. The incision is dissected under the skin and the flap is then inverted. Subcutaneous fat and sweat gland tissue are subsequently excised under direct visualization. ⁴⁰

Dai et al. added multiple micro perforations of approximately 3 mm in length to facilitate drainage of the operative area and reduce the incidence of subcutaneous hematoma, but whether pigmentation or scarring was left at the micro perforation site was not addressed by the authors. ⁴¹

He et al. meticulously excised the tissue spanning from the dermis to the superficial axillary fascia. Initially, they delicately separated the dermis from the subcutaneous tissue layer using fine scissors, thereby preserving the subdermal vascular network. Subsequently, they utilized an electric knife to dissect the subcutaneous tissue from the superficial axillary fascia layer. Finally, the entire sweat gland‐superficial axillary fascia complex, encompassing the distribution area of the apocrine sweat glands, was meticulously removed. ⁴² The entire subcutaneous sweat gland‐superficial axillary fascia complex is meticulously excised in this method, with a focus on preserving the subdermal vascular network to minimize the risk of flap necrosis. However, findings from current clinical studies suggest that apocrine sweat glands are predominantly distributed in the subcutaneous fat layer near the dermis, raising questions regarding the necessity of excising to the depth of the superficial axillary fascia layer. Additionally, the subfascial region beneath the superficial axillary fascia is known for its rich vascular supply. Consequently, inadvertent damage to subfascial blood vessels following intraoperative fascial disruption may lead to increased bleeding and postoperative complications.

Li et al. successfully preserved the superficial axillary fascia, leading to the disappearance of bromhidrosis post‐surgery. However, the follow‐up duration was limited, necessitating further long‐term observation. ⁴³ Yoshikawa et al. employed a double transverse incision approach, incorporating two incisions within the central axilla. In cases where the axillary hair distribution area is extensive, achieving clear removal of sweat gland tissue with a single incision can be challenging. ⁴⁴ Often, a single incision leads to excessive stretching of the skin for adequate visualization, resulting in suboptimal wound healing. The double transverse incision method addresses the need for enhanced visualization and offers greater convenience, while minimizing excessive skin stretching during the procedure. Nonetheless, a drawback of this approach is the presence of an additional incision scar post‐operation.

Li et al. innovatively altered the conventional incision pattern by implementing two W‐shaped incisions at the upper and lower poles of the axillary hair region for the removal of sweat gland tissue. This modification not only mitigates scarring but also facilitates improved wound drainage due to the strategic placement of the incisions. Furthermore, positioning the incisions at the upper and lower poles of the axilla reduces the likelihood of postoperative hyperpigmentation. ⁴⁵

1.6.3. Small incision scraping

Two small incisions approximately 1 cm in length are meticulously made within the axillary hair region to access the subcutaneous cavity. Utilizing a bromhidrosis scraping spoon, subcutaneous fat and sweat gland tissue are carefully scraped away, while also targeting the destruction of hair follicles until a lavender hue appears on the skin surface. This surgical technique effectively eradicates sweat gland tissue to alleviate bromhidrosis, albeit with a minimal risk of recurrence attributed to incomplete gland destruction.

Wang et al. introduced a novel serrated spatula, demonstrating superior efficacy in tissue removal compared to conventional spatulas. However, this innovation is accompanied by an elevated risk of skin necrosis. ⁴⁶

Some physicians employ a combination of clipping and scraping techniques in their approach. Certain surgeons opt for a combined approach involving both clipping and scraping methodologies. This entails creating a small incision in the mid‐axilla to access the subcutaneous cavity of the axillary hair region. Subsequently, under direct visualization, hair follicles, sweat glands, and adipose tissue are meticulously excised, followed by scraping of any residual subcutaneous fat, hair follicles, and sweat gland tissue using an axillary scraper. This dual‐manipulation approach, despite involving two surgical interventions, offers enhanced efficacy in treatment and diminishes the likelihood of recurrence.

1.6.4. Ultrasonic emulsification aspiration

Tumescent anesthesia is applied to the surgical site, followed by a small 5 mm incision. The ultrasonic cavitation effect induces tissue emulsification and fragmentation, complemented by negative pressure scraping to effectively target sweat gland tissue and hair follicles, achieving therapeutic outcomes. This approach is characterized by its simplicity, minimal scarring, and the ability of ultrasound to simultaneously separate and fragment tissue while promoting coagulation hemostasis, thus minimizing bleeding. However, prolonged exposure to subcutaneous ultrasound may result in local skin damage and necrosis. ³⁹ Therefore, careful attention to the dosage of tumescent anesthesia and the duration of subcutaneous ultrasound is imperative during this procedure. ⁴⁷

1.6.5. Liposuction

Injecting tumescent anesthesia within 1 cm of the outer axillary hair area, an incision of approximately 1 cm is made at the lowest point of the outer contour line. Subsequently, ophthalmic scissors ⁴⁸ , ⁴⁹ or a sharp liposuction tube ⁵⁰ is employed to meticulously separate the subcutaneous fat from the superficial fascial layer. The destruction of sweat glands ensues through suction with a blunt liposuction cannula under negative pressure until the inner surface skin attains a porcelain‐white appearance. In the event of residual sweat glands, they can be trimmed using a scraping spoon or ophthalmic scissors. This technique accelerates surgical proceedings, diminishes the risk of intraoperative infection, and results in minimal postoperative scarring owing to the exceedingly small incision. The advantages of the equipment utilized also contribute to reduced postoperative drainage, improved treatment outcomes, and a low recurrence rate, thus fostering high patient satisfaction. Nevertheless, proficiency in both equipment operation and technique execution is paramount. Since this method entails complete separation of subcutaneous fat from the superficial fascial layer during surgery, complications such as inadequate contact between the skin and subcutaneous tissue or sliding of the contact surface may occur despite postoperative axillary pressure dressing, potentially leading to skin ischemia and necrosis.

Zhang et al. refined this technique by implementing —one to two incisions measuring approximately 1 cm, tailored to the size of the treated area post‐tumescent anesthesia. Subsequently, they delicately separated the subcutaneous fat from the superficial fascial layer utilizing ophthalmic scissors. Sweat gland destruction ensued through suction using a specialized rotary cutter under negative pressure, followed by meticulous elimination of residual sweat gland tissue with a scraping spoon. ⁵¹ Post‐surgery, —four to five micro‐perforations were made for drainage purposes, and —three to five rolls of petroleum jelly gauze were employed for oil tincture application to secure the flap to the subcutaneous tissue. Notably, the utilization of a specialized rotary cutter device offers enhanced precision and ease of operation compared to traditional blunt liposuction cannula suction methods for sweat gland destruction. The mechanical principle advantageously ensures uniform suctioning and cutting of subcutaneous sweat glands in the axilla, mitigating the risks of over‐trimming or under‐trimming associated with liposuction. Additionally, the postoperative incorporation of drainage holes and oil tincture fixation technology effectively prevents postoperative wound fluid accumulation and reduces the likelihood of skin necrosis on the wound surface.

1.6.6. Endoscopic‐assisted bromhidrosis treatment

Hu et al. performed incisions of 10 and 5 mm in the mid‐axillary and posterior axillary lines, respectively, avoiding the axillary hair area. The deep fascia was gently dissected to establish a catheter gap. A 10 mm trocar and a 5 mm trocar were inserted through the incisions for observation and surgery, respectively. Carbon dioxide gas was insufflated intraoperatively, and a scalpel was utilized to create the subcutaneous surgical space. The apocrine gland was disrupted using endoscopic scissors. ⁵² This technique results in the presence of only —two to three minimally visible incisional scars post‐surgery. It provides a clear intraoperative field of view, ensuring reliable removal of acromegaly glands, minimizing the risk of recurrence, and achieving complete hemostasis. However, its implementation demands sophisticated equipment and presents operational challenges.

1.6.7. Application of FUE follicle extraction technology

Li et al. innovatively applied follicular unit extraction (FUE) technology in the treatment of bromhidrosis. The specific procedure involved shaving the operative area to a length of 1–2 mm, injecting a swelling solution, selecting an appropriate inner diameter follicle extractor, punching in the same direction as the hair follicle growth, inserting to a skin depth of approximately 2.5 mm, and extracting all hair follicles. ⁵³ The FUE technique results in only a few punctate bleeding spots post‐procedure, characterized by minimal trauma, few postoperative complications, and negligible disruption to daily activities. Significant improvement in odor was observed during the follow‐up period, suggesting the efficacy of the treatment. While the method shows promise, comprehensive clinical trials are necessary to validate its effectiveness and refine operational protocols.

1.6.8. Thoracic sympathectomy

The procedure operates by disrupting the fibers of the sympathetic ganglion, resulting in cessation of axillary sweat secretion. While this approach effectively eliminates sweat production, potential postoperative complications such as compensatory sweating, sensory abnormalities, Horner's syndrome, neuralgia, or pneumothorax may arise. Additionally, the procedure incurs higher costs, leading to reluctance among patients to undergo it. ⁵⁴

2. CONCLUSION

Current treatments for bromhidrosis primarily focus on removing or inhibiting the secretion of sweat glands and controlling bacterial growth. There is no universally ideal treatment method, and selection should be based on factors such as the severity of bromhidrosis, patient preferences, available hospital resources, and economic considerations.

For mild cases or those with scarring, topical medications represent a convenient, cost‐effective option with minimal side effects, albeit with limited efficacy and no curative potential. Injectable therapies and non‐surgical options like phototherapy may be considered if topical treatments prove ineffective. Patients with severe bromhidrosis or without scarring may opt for surgical or physical interventions aimed at gland destruction.

Botulinum toxin injections are commonly chosen due to their precise efficacy, safety profile, minimal adverse effects, and limited impact on daily activities. However, the safety and efficacy of alternative injectable drugs require further investigation due to limited clinical data. Oral medications are generally not recommended due to their potential for serious side effects.

Physical treatments such as phototherapy offer less invasive alternatives but lack specificity for sweat glands, leading to higher recurrence rates compared to surgical interventions. Some devices may also have limited popularity and demand higher operator proficiency.

Surgery remains the most effective option for radical reduction of sweat glands and symptom improvement in bromhidrosis. Advancements in surgical techniques have led to reduced complications, such as scar contracture and flap necrosis. Innovative equipment, such as negative pressure suction tubes and rotary cutters with negative pressure, have been introduced to enhance surgical outcomes. Although FUE shows promise as a new surgical approach, its efficacy requires validation through extensive clinical practice.

CONFLICT OF INTEREST STATEMENT

The authors have no conflicts of interest to declare.

ETHICS STATEMENT

Ethical approval does not apply to this article. This article does not include any research involving humans or animals. There are no human subjects in this article, therefore informed consent is not applicable.

Zhang J, Han P, Yang F, Jiang B. Advances in the treatment of axillary bromhidrosis. Skin Res Technol. 2024;30:e13895. 10.1111/srt.13895

DATA AVAILABILITY STATEMENT

Data sharing is not applicable to this article, as no new data were created or analyzed in this study.