What is Bromhidrosis?
Bromhidrosis, also known as Osmidrosis, or body odour, is a common condition in postpubertal individuals. In rare cases, bromhidrosis may become pathologic if it is particularly overpowering or if the bromhidrosis significantly interferes with the lives of the affected individuals. Bromhidrosis is a chronic condition in which excessive odour, usually an unpleasant one, emanates from the skin. Bromhidrosis is determined largely by apocrine gland secretion and can substantially impair a person’s quality of life.
Types of sweat glands and their functions
Human sweat glands are primarily divided into two types: apocrine and eccrine.
Eccrine glands are distributed over the entire skin surface, where they are involved in thermoregulation by means of sweat production.
In contrast, apocrine glands have a limited distribution involving the axilla, genital skin, breasts, periorbital and periauricular areas. Apocrine glands have no thermoregulatory role but are responsible for characteristic pheromonal odours.
They secrete a small amount of oily fluid, which is odourless upon reaching the skin surface. The characteristic odour is due to bacterial decomposition of the oily fluid.
Studies have shown that in comparison to controls, individuals with bromhidrosis display more numerous and larger apocrine glands.
Apocrine bromhidrosis is the most prevalent form of bromhidrosis and should be differentiated from the less common eccrine bromhidrosis. Several factors contribute to the pathogenesis of apocrine bromhidrosis. Bacterial decomposition of apocrine secretion yields ammonia and short-chain fatty acids, with their characteristic strong odours. The most abundant of these acids is (E)-3-methyl-2-hexanoic acid (E-3M2H), which is brought to the skin surface bound by 2 apocrine secretion odour-binding proteins, ASOB1 and ASOB2.
Axillary bacterial florae have been shown to produce the distinctive axillary odour by transforming nonodoriferous precursors in sweat to more odoriferous volatile acids. The most common of these are E-3M2H and (RS)-3-hydroxy-3-methlyhexanoic acid (HMHA), which are released through the action of a specific zinc-dependent N -alpha-acyl-glutamine aminoacylase (N-AGA). This aminoacylase has been demonstrated to also release other odoriferous acids from glutamine conjugates in sweat, which may be the basis of individual body odour.
In certain circumstances, eccrine secretion, which is typically odourless, assumes an offensive aroma and causes eccrine bromhidrosis. When eccrine sweat softens keratin, bacterial degradation of the keratin yields a foul smell. Ingestion of some foods, including garlic, onion, curry, alcohol, certain drugs (e.g., penicillin, bromides), and toxins may also cause eccrine bromhidrosis. Lastly, eccrine bromhidrosis may result from underlying metabolic or endogenous causes.
The role of excessive eccrine secretion, or hyperhidrosis, in the pathogenesis of bromhidrosis is unclear. Hyperhidrosis may promote the spread of apocrine sweat and contribute further to bromhidrosis by creating a moist environment, one ripe for bacterial overgrowth. Conversely, eccrine hyperhidrosis may cause a decrease in odour because the eccrine sweat flushes away the more odoriferous apocrine sweat.
Apocrine bromhidrosis is believed to be associated with a positive family history of hyperhidrosis in some ethnic groups, such as in Asians. Apocrine bromhidrosis occurs typically after puberty and is more common in men related to a greater number of apocrine gland activity.
Unlike eccrine bromhidrosis, apocrine bromhidrosis is believed to be more common in dark-skinned individuals. Epidemiologic studies have shown that an individual of African ancestry has the largest and most active apocrine glands based on the histological or pathological sections of their skin.
Eccrine bromhidrosis occurs in persons of all races.
Patients with bromhidrosis should be encouraged to maintain an appropriate level of hygiene with the use of antibacterial soaps and antiperspirants. Bromhidrosis patients also should be aware of the odour that may arise from dried sweat on clothes.
Patients present with particularly offensive body odour that most commonly originates from the axillary region. However, the condition may also occur as genital or plantar bromhidrosis. The odour has been described as pungent, rancid, musty, or sour in character.
Bromhidrosis is a metabolic and functional disease not typically associated with any anatomic disturbance. Therefore, results of physical examination of patients with axillary bromhidrosis are usually unremarkable. The skin appears normal, except when bromhidrosis is associated with concomitant skin conditions such as erythrasma, or trichomycosis axillaris, in which case concretions are visible on the hairs in the affected area.
Excessive secretion from either theapocrine or eccrine glands that become malodorous on bacterial breakdown is the predominant cause of bromhidrosis.
Inadequate hygiene and medical or dermatologic conditions associated with hyperhidrosis or overgrowth of bacteria may further contribute to its development. Examples include the following:
- diabetes mellitus
- trichomycosis axillaris
- colonization with other bacteria
Eccrine bromhidrosis may rarely be caused by metabolic disorders, primary disturbances in amino acid metabolism, sweaty feet syndrome, the odour of cat syndrome and hypermethioninemia.
Ingestion of certain foods, drugs, or toxic materials may cause eccrine bromhidrosis. Older medical textbooks report that offensive smells were characteristic of diseases like gout, scurvy, or typhoid.
- Liver failure (fetor hepaticus), which has a characteristic rotten-eggs odour in the breath and urine Renal failure, which is associated with urinelike odour.
- Schizophrenia, which may be associated with a characteristic unpleasant body odour.
- Olfactory hallucinations, in which the patient’s perception of body odour may be represented, sign of neurologic disease or organic brain lesions.
- Body dysmorphic disorder.
- Fish odour syndrome.
- Olfactory reference syndrome, which is characterized by a false belief of having significant and offensive body odour.
Typically, the olfactory perception of the diagnostician is the only clinical tool required for diagnosis. Chromatography or spectroscopy may help identify odour-producing chemicals; however, the specific identification of odoriferous molecules is largely of academic interest and lacks diagnostic or therapeutic importance. In addition, results of chromatography or spectroscopy do not help in differentiating normal odour from odour caused by bromhidrosis. A starch-iodine test can demonstrate areas of excessive sweating but would not characterize the associated malodor.
Skin biopsy is rarely indicated in bromhidrosis. However, skin biopsy may be used to evaluate apocrine glands if surgical treatment options are being
Evidence about histologic findings in patients with bromhidrosis is conflicting. Although some research indicates that no histologic abnormalities are seen in the skin or glands of patients with apocrine bromhidrosis when compared with control subjects, a few studies have shown that the number and the size of apocrine glands are increased in bromhidrosis skin. This finding suggests increased apocrine sweating as a possible cause of this troublesome condition.
Treatment and management
Several therapeutic modalities are available to treat body odour. Only miraDry provides a non-invasive treatment that offers a lasting solution for axillary hyperhidrosis and bromhidrosis. It should be understood that various surgical methods provide lasting results, however, they are associated with an increased risk of morbidity and risk of recurrence. When a treatment method is chosen, it is important to consider the cultural implications and the degree of impairment in quality of life, as well as the patient’s expectations and goals of treatment.
- Non-invasive miraDry treatment – long-lasting results
MiraDry is the only non-invasive treatment to permanently eliminate the axillary hyperhidrosis and bromhidrosis. The treatment is completed in one single session that takes about one hour. The procedure is painless, easy and the results are immediate and long-lasting.
The miraDry treatment uses the most advanced microwave technology applied in various fields of medicine over the past three decades and is now applied in dermatology to effectively eliminate the axillary hyperhidrosis and bromhidrosis. Miramar Labs in U.S.A. is the first company to gain FDA clearance to use microwave energy to combat excessive underarm sweating and odour.
MiraDry uses a non-invasive handheld device to deliver precisely controlled electromagnetic energy beneath the underarm skin to the specific area where eccrine and apocrine sweat glands are located, resulting in thermolysis of the sweat glands. While the sweat glands are being eliminated through electromagnetic technology, the top layers of the skin are simultaneously cooled and protected. Microwaves lie in the electromagnetic spectrum between infrared waves (such as LASER) and radio waves (RF devices).
With minimal to no downtime, miraDry is indicated for primary axillary hyperhidrosis and bromhidrosis treatment in adults 18 and older, as well, as in patients under the age of 18 with the consent of a legal guardian.
- Hygiene and topical antibacterial agents – temporary solution
Conservative measures, which aim to reduce bacterial florae and maintain a dry environment, include improved hygiene and topical therapy. Hygienic measures, such as adequate washing of the axillary vault, prompt removal of sweaty clothing, and the use of topical deodorant (which covers the odour and decreases bacterial counts) are beneficial in cases of apocrine bromhidrosis. Regular shaving of axillary hair prevents the accumulation of sweat and bacteria on the hair shafts. Electrolysis might also be considered for hair removal to minimize bacterial growth.
Use of topical antibiotics such as clindamycin and erythromycin and antiseptic soaps may yield clinical benefit by limiting the growth of the contributory bacteria that decompose apocrine secretions, liberating fatty acids that have peculiar smells. Topical antibiotics should only be used when other antiseptics are ineffective because they are associated with a greater risk of bacterial resistance.
- Drying agents – temporary solution
Measures to enhance drying and limit maceration, such as the use of antiperspirants including aluminium chloride, may improve bromhidrosis of either apocrine or eccrine origin, particularly if hyperhidrosis is a contributing factor. Antiperspirants, unlike deodorants, contain aluminium salts, which inhibit sweat production.
Iontophoresis, which disrupts sweat production, has a role in the treatment of eccrine bromhidrosis. With this method, a small electric current is passed through the skin while the affected area is placed under tap water. Typically used only for volar skin, this treatment is time intensive and should be considered only if excessive eccrine sweating contributes to the patient’s body odour. Amelioration of hyperhidrosis does not reduce apocrine sweat production.
Conservative methods are ideal for mild cases. However, they do not offer a definitive cure, and results may be unsatisfactory if odour reduction is short lived and incomplete. Systemic agents decrease sweating, but their use can be limited by their adverse effect profile.
- LASER και btx – temporary solution
For patients who desire more long-lasting treatment, a few nonsurgical options have been developed, although the data on these options are limited. A frequency-doubled, Q-switched Nd:YAG laser (1064 nm) has been effective in axillary bromhidrosis. More recently, the 1444-nm Nd:YAG laser has been used to achieve subdermal coagulation and destruction of apocrine glands, leading to effective management of bromhidrosis. Over 75% of patients reported satisfaction with the procedure up to 6 months afterwards.
The inhibitory action of botulinum toxin A (btx) to decrease sweat production by denervating eccrine sweat glands has also been applied to successfully treat axillary hyperhidrosis. The effect on axillary apocrine gland secretion is unknown; however, local injections of botulinum toxin A reduced axillary body odour in a small number of healthy subjects, and 1 case of improved genital bromhidrosis after botulinum toxin A treatment is reported.
- Surgical Care – long-lasting results
Surgical treatment for axillary bromhidrosis has been used in a limited fashion in the United States; however, several surgical techniques are used more widely in Asian countries, where axillary odour causes more social and psychological distress.
Clearly, surgical reduction in the number of apocrine glands diminishes apocrine secretion, and because some histologic evidence to suggest overactive apocrine sweat glands contributes to bromhidrosis, surgical techniques may be the most satisfactory methods of treatment. Surgical treatment improves the long-term management of bromhidrosis, but it is associated with an increased risk of morbidity, including scarring, surgical complications, and risk of recurrence. In recent years, new minimally invasive techniques with less morbidity have been developed. These include procedures with smaller incisions, which leave the vascular plexus as well as superficial fascia intact and may lead to satisfactory results with fewer adverse effects.
- Surgical removal – long-lasting results
A multitude of surgical methods have been reported to date, which can be categorized into the following 3 classic types:
- Removing only subcutaneous cellular tissue without removing skin: In some reports, axillary superficial fascia is removed in addition to the apocrine glands, with good results. In minimally invasive procedures, this fascia is left intact. One novel technique used subcutaneous curettage combined with fat trimming to create a smooth surface on the axillary skin flap while removing the apocrine glands.
- Removing skin and subcutaneous cellular tissue en bloc.
- Removing skin and cellular tissue en bloc, as well as removing the subcutaneous cellular tissue of the adjacent area: this is often performed by using a shaving technique on the subcutaneous tissue.
Depending on the depth of the surgical injury, regeneration of gland function over a period of years may be observed. Subcutaneous tissue removal has also been combined with carbon dioxide LASER to vaporize the residual apocrine glands.
- Superficial liposuction curettage – long-lasting results
The superficial liposuction curettage technique is an outpatient procedure that has the advantage of being less traumatic than open surgery. Small incisions are made in the axilla, and a suction device is inserted that removes the subcutaneous tissue. This procedure offers a smaller incision, lower complication rates, and minimal postoperative care. However, its associated recurrence rate is higher than that of open surgery, leading to decreased patient satisfaction on long-term follow-up. A similar procedure, ultrasound-assisted suction aspiration, liquefies fat and sweat glands. This treatment has recurrence rates lower than those of traditional superficial liposuction curettage and results in similarly small scars.
Upper thoracic sympathectomy has also been performed for axillary bromhidrosis and palmar hyperhidrosis.
The omission of certain foods may be of value if these factors can be isolated or identified as contributory factors to the bromhidrosis. Common culprits include curry spices, onions, garlic, and alcohol.
The goals of pharmacotherapy are to reduce morbidity and to prevent complications.