(See also Introduction to Sweating Disorders Introduction to Sweating Disorders There are two types of sweat glands: apocrine and eccrine. Apocrine glands are clustered in the axillae, areolae, genitals, and anus; modified apocrine glands are found in the external auditory... read more .)
Apocrine secretions are lipid-rich, sterile, and odorless but become odoriferous when decomposed by bacteria into volatile acids on the skin surface.
Eccrine sweat is generally not malodorous because it is nearly 100% water.
Eccrine bromhidrosis can occur when bacteria degrade keratin that has been softened by eccrine sweat. Eccrine bromhidrosis can also result from ingestion of foods (eg, curry, garlic, onion, alcohol) and drugs (eg, penicillin).
Studies suggest a strong correlation between bromhidrosis and wetness or stickiness of earwax (in association with a single nucleotide polymorphism of the ABCC11 gene [1 Reference Bromhidrosis is excessive or abnormal body odor caused by decomposition by bacteria and yeasts of sweat gland secretions and cellular debris. (See also Introduction to Sweating Disorders.) Apocrine... read more ]).
In some people, a few days of washing with an antiseptic soap, which may be combined with use of antibacterial creams containing clindamycin or erythromycin, may be necessary. Shaving the hair in the armpits may also help control odor.
1. Nakano M, Miwa N, Hirano A, et al: A strong association of axillary osmidrosis with the wet earwax type determined by genotyping of the ABCC11 gene. BMC Genetics 10:42, 2009. doi: 10.1186/1471-2156-10-42.