Bromhidrosis

Bromhidrosis is a chronic medical condition that presents with excessive sweating (i.e., hyperhidrosis) and is associated with foul-smelling body odor. Although most individuals produce sweat-related body odor, individuals with bromhidrosis experience excessive sweating and odor, which can negatively interfere with their quality of life. Bromhidrosis is subdivided into two types, including apocrine bromhidrosis and eccrine bromhidrosis. 

These subtypes are named according to the types of sweat glands that are involved in secreting sweat, specifically the apocrine glands and eccrine glands. The apocrine glands develop after puberty, secrete pheromones, and are located in areas with many hair follicles (e.g., the scalp, axilla, areola, and anogenital regions). Apocrine sweat contains lipids and proteins that can be broken down by bacteria, leading to a foul-smelling odor. Eccrine glands are widely distributed all over the body with the exception of the genital region. Eccrine sweat is composed of water and salt and is responsible for thermoregulation.

The cause of bromhidrosis is multifactorial; however, the primary mechanism for the associated foul smell is bacterial degradation of sweat gland secretion. For example, in apocrine bromhidrosis, the foul-smelling lipids and proteins found in apocrine and eccrine secretions are degraded by certain types of bacteria (e.g., Corynebacterium spp., Staphylococcus spp., and Cutibacterium spp.). Apocrine secretion of pheromones also contributes to malodorous perspiration, even prior to its bacterial degradation.

Other factors associated with bromhidrosis include hormonal changes (e.g., increased hormone levels during puberty, pregnancy, or menopause), ingestion of odor-promoting compounds (e.g., garlic, onions, curry, alcohol), poor hygiene that results in a build-up of bacteria, underlying medical conditions (e.g., liver and renal failure produces ammonia-like smell; phenylketonuria, a rare disorder that causes phenylalanine to build up and produces a characteristic musty odor), heavy metal exposure, and medications (e.g., penicillin, duloxetine).

Risk factors for bromhidrosis include elevated levels of dihydrotestosterone, individuals with larger and more numerous apocrine glands, and concomitant hyperhidrosis (i.e., excessive sweat production).

Signs and symptoms of bromhidrosis include unpleasant and offensive smells described as “sour" or “rancid” in areas associated with hyperhidrosis and bromhidrosis (i.e., axillae, groin, feet). Individuals may notice more foul-smelling odors during high-intensity activity or warm temperatures. Clothing stains may also be present due to the interaction between sweat, bacteria, and clothing fabrics. 

Diagnosis of bromhidrosis is purely clinical and begins with a thorough review of symptoms and medical history. Pertinent information includes hygiene habits (e.g., how often the individual bathes), diet, heavy metal exposure, medical conditions (e.g., renal and liver dysfunction, phenylketonuria), and medication history (i.e., history of antidepressant use or antibiotics). Individuals should be questioned as to whether their body odor has been noticed by others. The most common chief complaint is malodorous odor in characteristic areas (i.e., axilla, groin, feet) that slightly improves with bathing and worsens in warm temperatures and with high-intensity exercise. Most importantly, these symptoms must interfere with the individual’s quality of life in order to meet diagnostic criteria. A physical exam can help identify the affected areas. In individuals with obesity, the exam may reveal skin maceration in intertriginous areas as a result of excess sweating. Laboratory blood testing is often normal and is not necessary for individuals with localized bromhidrosis. In individuals with generalized bromhidrosis, blood testing (e.g., comprehensive metabolic panel) can help to evaluate systemic conditions, such as liver and renal failure.

Treatment of bromhidrosis consists of a combination of non-pharmacologic and pharmacologic options aimed at improving personal hygiene and reducing sweating and bacteria on the skin. This can be accomplished by washing the affected areas daily, though excessive washing is not recommended as it can cause skin irritation. Non-pharmacologic options such as antibacterial soaps may help decrease bacterial colonization, whereas deodorants may help decrease odor. Individuals with hyperhidrosis may benefit from an antiperspirant, which reduces sweating by temporarily plugging the sweat glands. Because body hair can trap bacteria and debris, hair removal (i.e., shaving, epilation, or laser removal) may reduce odor. Pharmacologic options to reduce odor can also include antibacterial creams, including topical erythromycin or clindamycin. Botulinum toxin injections may also be useful as they block the release of acetylcholine (i.e., a neurotransmitter that signals sweat glands to produce sweat) and treatment effects may last up to 6 to 12 months. In individuals who do not respond to the aforementioned treatment strategies, surgical removal of the sweat glands or destruction of glands via laser therapy may be reasonable options, although the evidence on these approaches is limited.

Bromhidrosis is a chronic medical condition that presents with excessive sweating (i.e., hyperhidrosis) and is associated with foul-smelling body odor. Bromhidrosis is subdivided into two types, including apocrine bromhidrosis and eccrine bromhidrosis. These subtypes are named according to the types of sweat glands that are involved in secreting sweat, the apocrine glands and eccrine glands, respectively. Bromhidrosis is multifactorial; however, its primary mechanism is due to the build-up of bacterial degradation of sweat gland secretions. Diagnosis is clinical and is confirmed with a thorough review of symptoms and medical history. Treatment includes a combination of pharmacologic (e.g., botulinum toxin injection, antibacterial topical agents) and non-pharmacologic modalities aimed at decreasing bacterial colonization (e.g., antibacterial soaps), perspiration (e.g., antiperspirants) and odor (i.e., deodorants). In refractory cases, surgical resection or destruction of the sweat glands may be a reasonable choice, although data is limited to case reports.