To a micro-organism, the human skin seems very much like the planet Earth seems to us. Just like our planet, our bodies contain numerous different environments, ranging from dry deserts (e.g. the forearm) to tropical forests (e.g. the groin). Each environment possesses certain advantages and disadvantages and different micro-organisms have adapted to certain regions of the body for their particular needs.
The surface of the skin itself comprises several distinct environments. Areas such as the axilla (armpit), the perineum (groin) and the toe webs provide typically moister regions for bacterial growth. These "tropical forest" environments often harbour the largest diversity amongst the skin flora. Typical organisms include Staphylococcus aureus, Corynebacterium and some Gram-negative bacteria. The bulk of the human skin surface, however, is much drier and is predominantly inhabited by Staphylococcus epidermidis and Propionobacterium ( SIUC).
How many micro-organisms inhabit our skin?
|Scanning electron microscope image of a modern human head louse, Pediculus humanus. Credit: Vincent S. Smith, University of Glasgow.|
A mite photographed in very high magnification, using a scanning electron microscope. Credit: Gary Wife
|Scanning electron microscope image of Sarcoptes scabiei. Image from Jens G. Mattssen, MSc., Ph.D., Department of Parasitology, |
National Veterinary Institute, Uppsala, Sweden.
Lice are perhaps the most common of these body dwellers. They have the ability to get everywhere from your hair to your armpits to your groin. Nonetheless, they tend to be more itchy than damaging -- unlike ticks, which can cause any number of nasty and exotic diseases from Royal Farm Virus to Omsk Hemorrhagic Fever. [ Editor's Note: And don't forget Lyme Disease.] And then there is the scabies mite, which is believed to infest millions of humans worldwide, and is able to burrow into the body to hide itself, causing a nasty itch.
Fortunately, its close relative, the follicle mite, which is found on everybody in the world, happily munches dried skin cells and causes far less aggravation. [ Editor's Note: Don't forget, however, that many persons are allergic to the excretions of mites that can also live on pillow and mattress dust for long periods of time. By the way, have you ever taken a close look at the standard electron microscope snap-shots of these weird creatures. They look like they just stepped out of a B-class science fiction or horror movie.] And not all body parasites creep and crawl - you can find fungi in your hair and mould in your skin folds if you look closely enough.
In addition to his statistics, Rosebury treats us to a fascinating tour through little-known by-ways of literature and anthropology, documenting historical and cultural attitudes to obscenity - regaling us with tales from Rabelais and other great scatologists.
1. Theodor Rosebury, Life on Man (Secker and Warburg, London, 1969).
2. Question by Roger Taylor, "Bodily Breeding: How Many Different Species Live on or in the Average Human Body and What is the Total Population of These Guests?, "New Scientist (September 30, 1999)[ www.newscientist.com ].
3. The New York Times, Science Section D (October 2, 2000).
4. The Los Angeles Times, p. B2 (October 26, 2000).
5. Paul Taylor (January 28, 2000) [ www.nous.org.uk/Rosebury.html ].
6. Roger M. Knutson, Fearsome Fauna: A Field Guide to the Creatures That Live in You (W. H. Freeman; 1999)
7. Roger M. Knutson, Furtive Fauna: A Field Guide to the Creatures Who Live on You (Penguin; 1992)(Ten Speed Press; 1996).
With this multitude of organisms living on our skin, some good, some not so good, how can we make sure we maintain our skin to be a healthy, balanced ecosystem?
Our skin continually replaces itself, new skin cells are replacing dead ones and the process keeps going until we die. There are however ways, we can promote the health of our skin and its micro-organisms.
Following a natural skin care regime, that is using natural exfoliants, cleansers, toner and moisturisers, we can reduce the risk of certain microbes becoming dominant and potentially causing problems.
Exfoliation is very important to keep the number of dead cells on our skin to a healthy level and in reducing the number of some mites and other micro-organisms discussed above.
Cleansing our skin, using a natural skin cleansing lotion on a daily bases, and two or three times a week applying a deep cleansing facial/body mask, helps to keep pores and skin folds clean and reduces the risk of skin irritation, acne, fungal infections as well as other skin problems.
Toning is a process often left out of a skin care regime, but this is a big mistake, because toning the skin closes pores and thus reduces the risk of external environmental particles, including bacteria, from entering the pores and potentially causing problems. In addition, it helps to re-establish and maintain the Acid Mantel which provides protection of our skin. It is a must include step for anyone who is serious about maintaining healthy, vibrant skin.
Finally, moisturising helps to preserve the moisture in your skin and adds nutrients and therapeutic substances, which your skin can utilise to protect, hydrate and defend itself from the various environmental assaults on it.
As we age and the skin looses some of it regenerative power, we may wish to provide it with additional help. Using anti-aging creams that help in stimulating circulation, promote collagen production and is soothing and hydrating, may well be added to a skin care regime to help reduce the wrinkles and fine lines that start to form as we get older.
Danny Siegenthaler is a doctor of traditional Chinese medicine and together with his wife Susan, a medical herbalist and Aromatherapist, they have created Natural Skin Care Products by Wildcrafted Herbal Products to share their 40 years of combined expertise with you.
They practice Herbal and Chinese medicine at their Wildcrafted Cottage Clinic.
© Wildcrafted Herbal Products 2008