This is a 4-week series focused on bacteria found on our skin, in particular Staphylococcus aureus, a bacterium that can lead to infection and complications in eczema patients. I’m honored to have Dr. Clay Cockerell, the clinical professor of dermatology and pathology and the director of the Division of Dermatopatholgy at University of Texas Southwestern Medical Center in Dallas, Texas, to help in this series.
More on Dr. Cockerell – Dr. Clay Cockerell was the president of the American Academy of Dermatology in 2005. He is a renowned medical educator having overseen an educational program designed to train the next generation of dermatologists and dermatopathologists and the author of numerous papers and textbooks. He is a board-certified dermatologist and dermatopathologist licensed in many states throughout the U.S. His clinical expertise is in skin disorders and his passion has led him to co-found TopMD Skin Care, the company behind CLn® BodyWash.
Everyone’s Skin has Bacteria
Our skin is home to about 1 trillion microscopic organisms such as bacteria and fungi, and not all are bad – some are beneficial to us and some are harmless, but some are harmful like the Staphylococcus aureus bacterium (“Staph”) and Streptococcus pyogenes (“Strep”) that can cause skin infections. You can read more about the Human Microbiome Project of National Institutes of Health in this interview with Elizabeth Grice.
Marcie Mom: Dr. Clay, I read from this table that the bacteria commonly found on our skin are (1) Staphylococcus epidermidis, (2) Staphylococcus aureus, (3) Streptococcus pyogenes (4) Corynebacteria and (5) Mycobacteria. Which bacteria are good for us (for instance, prevent colonization of harmful bacteria) and which bacteria are harmful?
Dr. Clay: Staphylococcus epidermidis is part of the normal bacterial flora that lives on our skin and is a beneficial bacterium. In fact, they serve in many ways to “police” the skin and prevent dangerous ones such as S. aureus and S. pyogenes from growing and “setting up shop”. These latter two may cause boils, folliculitis, cellulitis and erysipelas, all examples of skin infections. Corynebacteria exist in several different species. C. acnes lives in hair follicles normally, but plays a role in the development of acne in acne-prone individuals. Other forms of Corynebacteria can also cause more serious infections such as C. minutissimum, which causes pitted keratolysis and juvenile plantar dermatosis, and C. diphtheria, which can cause cutaneous diphtheria, a rare form of cellulitis. There are also many different species of Mycobacteria, some of which are harmless and live in certain areas of the body such as the groin (M. smegmatis). Others are harmful and can cause cutaneous tuberculosis and atypical mycobacterial infections such as Swimming Pool granuloma (M. marinum) and infections acquired from getting pedicures when exposed to infected water in nail salons (M. fortuitum).
Do We Need More Good Bacteria?
Most bacteria tend to reside in moist areas of skin, along skin folds. I read that diet, health, age and environment also affect the amount of bacteria on our skin. Let’s tackle the good bacteria on our skin first – is there anything that one can do (and should one try) to increase the amount of good bacteria on our skin? Conversely, will frequent hand washing and use of sanitizers and anti-septic sprays remove good bacteria that our body needs? For a child whose immunity has yet to be fully developed, should he or she be washing hands more frequently or less than an adult?
Dr. Clay: The best way to increase the “good” bacteria is to have good hygiene, which prevents exposure to the “bad” bacteria (i.e., wash with a good soap and water and use hand sanitizers periodically). The good bacteria will naturally grow on your skin and live in harmony with our bodies naturally, as our body has certain factors, such as local immunity and chemicals on the skin surface, that create just the right environment. Bacteria multiply exponentially, so when its population is temporarily decreased, as after the use of hand cleanser, it re-grows quite quickly and returns to its normal concentration. The only way to truly “sterilize” so that the normal bacteria would not return would be to wash many, many times a day and even then, it is virtually impossible to get the skin totally sterile. In fact, individuals who do over-wash often cause significant skin irritation, which paradoxically can cause the “bad” bacteria to enter and colonize the skin and even cause an infection.
There are individuals who have certain skin diseases that predispose them to become colonized with “bad” bacteria like Staph, especially those with atopic dermatitis, also known as eczema. These patients need to use more aggressive measures to get rid of these bacteria, as they can worsen the skin condition and lead to more serious infections. These patients often require systemic antibiotics or topical antibacterial agents including bleach, as administered in bleach baths, or bleach-containing body washes like the one I have been involved in developing, CLn® BodyWash, which can be used in a shower also.
Children don’t really need to wash their skin more than adults, as their immunity to bacteria develops very soon after birth. In fact, children’s skin can be more sensitive than adult skin, so care should be taken not to over wash with harsh soaps and detergents. Skin in elderly individuals also is less able to tolerate dryness, so the same caution should be taken by them, too.
People who are Staph carriers (i.e. abnormally harbor Staph on their skin) are prone to developing boils and other infections and can spread the Staph to family members. They, too, should take measures to try to decrease the spread of Staph by using topical antibiotics and antiseptic washes.
MarcieMom: Thank you Dr Cockerell for the detailed explanation of the various bacteria on our skin. Next week, we will discuss specifically on staph bacteria.