In today′s world, natural body odour is mostly considered as being unpleasant and combated by intensive cleansing, deodorants and perfumes. However, there is evidence that volatile body compounds provide the recipient with important information. Here, we present the chemical identity of odorous compounds derived from odourless precursors within sweat and sebum. Moreover, distinct volatile markers may be relevant for the clinical diagnosis of disease. Interestingly, ageing seems to correlate with the appearance of specific compounds that convey the so-called old man smell. Finally, it is discussed if human skin odour has the quality to act as pheromone transmitting information between individuals in terms of major histocompatibility complex type or reproductive status.Key words: body odour -pheromone -chemosignalling -behaviourageing -disease
Accepted for publication 24 May 2012Skin Odour: nothing is more remarkable than a smell!The sources of skin odour contributing to an individual 'odour signature' are diverse. A chief producer is the apocrine gland, located in the axillary, groin and anogenital regions, as well as in the umbilicus, eyelid (Moll's glands), areola and the external auditory meatus. They are fully developed up to reproductive maturity. The characteristic odour of anatomic sites rich in apocrine glands is formed from the interaction between odourless (water soluble) precursor molecules found in the glands secretion and the cutaneous microflora (1,2). In particular, aerobic Corynebacteria metabolize odourless steroids producing 16-androstenes (5a-androstenol, 5a-androstenone) with a pungent musk-and urine-like odour (3). It is, therefore, not surprising that men have been reported to have more numerous and larger apocrine glands than women (4). Correspondingly, axillary androstenone levels are much higher in men than in women (5). Moreover, volatile C6-C11 acids, the most prominent being 3-methyl-