Body odor

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Body odor
Classification and external resources
ICD-10 L75.0
ICD-9 705.89
DiseasesDB 28886
eMedicine derm/597 

Body odor (spelled body odour outside the United States), often abbreviated as B.O., or bromhidrosis (also called osmidrosis and ozochrotia) (also known as "Apocrine bromhidrosis," "Bromidrosis," "Fetid sweat," "Body smell," "Malodorous sweating," and "Osmidrosis"[1]:779[2]:707) is the smell of bacteria growing on the body. These bacteria multiply rapidly in the presence of sweat, but sweat itself is almost completely odorless to humans. Body odor is associated with the hair, feet, groin (upper medial thigh), anus, skin in general, armpits, genitals, pubic hair, belly button and ears (behind the ears)[citation needed].

Contents

[edit] Specificity

Body odor can smell pleasant and specific to the individual, and can be used to identify people, though this is more often done by dogs and other animals than by humans. An individual's body odor is also influenced by diet, gender, genetics, health and medication. Propionic acid (propanoic acid) is present in many sweat samples. This acid is a breakdown product of some amino acids by propionibacteria, which thrive in the ducts of adolescent and adult sebaceous glands. Because propionic acid is chemically similar to acetic acid with similar physical characteristics including odor, body odors may be identified as having a vinegar-like smell by certain persons.[citation needed] Isovaleric acid (3-methyl butanoic acid) is the other source of body odor as a result of actions of the bacteria Staphylococcus epidermidis,[3] which is also present in several strong cheese types.

[edit] Genetics

Body odor is largely influenced by major histocompatibility complex (MHC) molecules. These are genetically determined and play an important role in immunity of the organism. The vomeronasal organ contains cells sensitive to MHC molecules in a genotype-specific way. Experiments on animals and volunteers have shown that potential sexual partners tend to be perceived more attractive if their MHC composition is substantially different. This behavior pattern promotes variability of the immune system of individuals in the population, thus making the population more robust against new diseases.

A recent study suggests that body odor is genetically determined by a gene that also codes the type of earwax one has.[4][5] East Asians (those of Chinese, Japanese and Korean descent) have the type of sweat glands which even after hitting puberty still don't produce the chemicals found in the perspiration of other races. East Asians evidently have a greater chance of having the 'dry' earwax type and reduced axial sweating and odor. This may be due to adaptation to colder climates.[6]

[edit] Alterations

Body odor perceived as offensive may be reduced or prevented by using deodorants, and although body odor is commonly associated with hygiene, its presentation can be affected by changes in diet as well as those other factors discussed above.[7]

[edit] See also

[edit] References

  1. ^ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0721629210.
  2. ^ Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0071380760.
  3. ^ Ara K, Hama M, Akiba S, et al. (2006). "Foot odor due to microbial metabolism and its control". Can. J. Microbiol. 52 (4): 357–64. doi:10.1139/w05-130. PMID 16699586. 
  4. ^ "Japanese Scientists Identify Ear Wax Gene". New York Times. http://www.nytimes.com/2006/01/29/science/29cnd-ear.html?ex=1296190800&en=7f6c667589328421&ei=5088&partner=rssnyt&emc=rss. Retrieved on 2007-07-05. 
  5. ^ Yoshiura K, Kinoshita A, Ishida T, et al. (2006). "A SNP in the ABCC11 gene is the determinant of human earwax type". Nat. Genet. 38 (3): 324–30. doi:10.1038/ng1733. PMID 16444273. http://www.nature.com/ng/journal/v38/n3/abs/ng1733.html. 
  6. ^ Morris, Desmond (2007). The Naked Woman. New York: Thomas Dunne Books. pp. 121. ISBN 0312338538. http://books.google.com/books?id=Wa9zntiEKeAC&pg=PA121&dq=desmond+morris+orientals+incidentally&ei=JvWxSMWvBZu2tgPZ98i4BA&sig=ACfU3U1ZQgijLEIHuOwbEe41jpaziBbWOQ. 
  7. ^ "Learn How to Fight Body Odor". http://www.mdhealthnetwork.org/BodyOder.html. Retrieved on 2007-07-05. 

[edit] External links

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