Bromhidrosis (Sweat and Odor)

To better understand where odor comes from, and how to control it, it helps to know a little bit about sweat glands.

Humans have two different types of sweat glands: the eccrine glands and the apocrine glands.

Eccrine sweat glands are found in large numbers on the soles of the feet, the palms, the forehead, the cheeks, and in the armpits. These glands produce large volumes of watery, usually odorless sweat. Hyperhidrosis, or excessive sweating, affects the eccrine glands.

Apocrine glands are different. They are found mostly in the armpits and genital region. They produce a thick, viscous fluid. When this fluid comes in contact with bacteria on the skin's surface, it produces a characteristic potent smell. Apocrine sweat is sometimes called "anxiety sweat." While eccrine sweat is typically produced to control body temperature (such as during exercise), apocrine sweat is produced as a reaction to stress, fear, pain, or sexual stimulation. 

Because the interaction between sweat and bacteria on your skin influences body odor, your microbiome is an important factor. The microbiome is defined by the U.S. National Institutes of Health as "the collection of all microbes, such as bacteria, fungi, viruses, and their genes, that naturally live on our bodies and inside us." Things that cause shifts in your skin microbiome can also cause changes in body odor. For example, many deodorants work by changing the pH of your skin so that the pH is not hospitable to odor-causing bacteria (a ph of ~6-7 is preferred by odor-causing skin bacteria). If you change your deodorant brand, you may notice a change in body odor while your microbiome adjusts to the new product and new pH. Experts recommend allowing a couple weeks for your body to adapt to a new deodorant before deciding whether that deodorant works for you, or not. Hormonal changes such as during puberty, pregnancy, menopause and old age can also impact your microbiome and body odor. Keep in mind that the microbiome is important for healthy skin. Attempting to rid your skin of all bacteria is not recommended. 

Typically, people who suffer from primary hyperhidrosis (hyperhidrosis not related to another medical condition and not related to a medication being taken) do not have unusual problems with body odor. This is because the large volume of sweat that their bodies produce comes from their eccrine glands and that sweat tends to wash away bacteria and apocrine sweat. Body odor can occur, however, if a person sweats sporadically and the sweat is allowed to dry on the skin. Bacteria on our skin "love" to ingest proteins from the apocrine sweat. When skin bacteria digest the sweat proteins and “poop” out their waste, characteristic body odor is created. This sweat-ingest-poop-smell cycle takes about one hour to complete.

To help reduce or prevent odor, consider the following tips:

• If you are experiencing an odor problem, with or without hyperhidrosis, keep the body area in question dry. Antiperspirants, powders, and frequent clothing changes can help in this regard.
  
  
• To help prevent and mask odor, a deodorant is also helpful (note that many antiperspirants include deodorants). While we recommend applying an antiperspirant at night to control sweating, for body odor you may want to ALSO apply a deodorant or antiperspirant/deodorant combination product in the morning.
  
  
• Another way to help decrease unwanted body odor is to remove body hair from the problematic area. Shaving works well but waxing, laser-based hair removal, or miraDry treatment of the underarms is even better. Hair removal helps by removing a biofilm in the hair follicles that contributes to body odor. miraDry destroys apocrine sweat glands. 
  
  
• If you have received botulinum toxin injections for excessive sweating, or another excessive sweating treatment, and have stopped using or needing an antiperspirant, note that you may still want a deodorant product but may not need to use it as often, some trial and error may be necessary.
  
  
• Also wash regularly with an antibacterial soap like Dial, Safeguard, or Zest.
  
  
• Sometimes changes in diet can help, too, especially limiting garlic intake, but experts say that diet is actually less impactful on body odor than most people think. 
  
  
• If you are having problems with odors lingering on clothing even after laundering, try rinsing clothing with white vinegar prior to washing and/or adding an extra rinse cycle post-wash. Washing sweaty clothes as soon as possible after wearing can also help. A laundry detergent review from the NY Times is available here. 
  
  
• If these methods do not work, consult a dermatologist or other medical professional.
  

If you are experiencing severe foot odor, wetness and the body's "regular" bacteria may not be the only issues. Extreme foot odor is often caused by an overgrowth of a different type of bacteria. This bacteria particularly likes the warm, moist environment of the feet. To help solve the problem, both the bacteria and the moisture must be addressed. To control moisture, change your shoes and socks frequently and use powders or antiperspirants as recommended above. If necessary, a dermatologist or podiatrist can help you find additional ways to control foot moisture. If you feel you have excessive sweating in your feet (plantar hyperhidrosis) read our complete content here. To help control bacteria, wash with an antibacterial soap, and discard any moist, odoriferous shoes or socks. Additionally, it will most likely be necessary for you to see a healthcare professional, such as a dermatologist or podiatrist. He or she may prescribe a topical or oral antibiotic.

While odor can be very embarrassing, help is available. Please do not suffer in silence. Talk to a podiatrist, dermatologist, or another physician about your concerns and use the tips above to start better managing odor. To learn more about body odor and how it can be associated with stress sweating, read our blog on the topic.