Dr. Sarah Norrenberg

Pediatric Dermatologist
Derma Lausanne; Lausanne, Switzerland

Dr. Norrenberg is a pediatric dermatologist with a particular interest in sports-related dermatoses. Before opening her private practice in Lausanne, she worked as Senior Resident of the Pediatric Dermatology unit at the University Hospital of Lausanne and the Children’s Hospital of Lausanne. As many athletes prepare for the Paris Olympic Games, skin and sports are hot topics.

We interviewed Dr. Norrenberg to learn more about the fields of sport and dermatology.

Behind The Business Woman



What inspired you to publish a medical paper on Sports & Dermatology (Dans la peau des sportifs: dermatologie du sport)1?


In Switzerland, many people practice sports intensively, and many of my patients are retired athletes and/or future ones. As such, I am regularly consulted for skin problems induced by intensive sports training, especially in teenagers and young adults, as I am a pediatric dermatologist. My personal experience (practicing many sports myself) and my passion for sports in general have driven me to understand better and explore solutions to best manage dermatological conditions related to sports. As I looked into the medical literature, I realized a paucity of publications on the topic.

This motivated us to publish this medical paper because dermatological lesions in athletes are frequent and too often trivialized. Although Olympic athletes intrinsically represent health and well-being, extensive training and environmental conditions can result in significant skin conditions that can be harmful and even limit athletes from participating and competing to their full potential. Effective preventive measures are available, and the aim of this article was to help doctors diagnose the condition and identify the factors that may lead to it, to optimize patient care.

What are the most common sports dermatoses?

We generally classify sport-related dermatoses into four categories: traumatic & mechanical dermatoses (abrasions, blisters, corns, piezogenic papules, chafing, acne mechanica, black heel), infectious dermatoses (fungal, viral, and bacterial), inflammatory dermatoses (eczema, contact dermatitis, urticaria), and environmental dermatoses (dermatoses induced by cold, water, heat, and UVR).

Which category of sport-related skin manifestations do you see more often?

Traumatic and infectious dermatoses represent the vast majority of skin problems I see in my very sporty patients. They are also the major challenges endurance athletes face in the Olympics (marathon runners, triathletes, long-distance swimmers, and marathon swimmers). These sports induce constant frictional and traumatic forces on numerous body areas. The most common skin complaints in endurance sports are friction bullae and jogger’s nipples.

Friction bullae are due to repetitive frictional forces combined with moisture. The most commonly affected sites are the tips of the toes, the balls of the feet, and the posterior heel. Prevention is key in decreasing frictional forces and preventing moisture. Tension can be reduced with properly fitting shoes and wearing socks with low friction, particularly on the side facing the skin. Moisture reduction can be accomplished with acrylic or polyester socks that wick away sweat. Antiperspirant powder may be be used.

Jogger’s nipples are caused by repetitive friction to the nipples, leading to painful irritation, fissures, and bleeding. A tight-fitting, coarse cotton fabric shirt is usually the culprit. Prevention includes wearing clothes that reduce irritation, such as supportive jogging bras for women, and wearing lycra or silk shirts instead of cotton shirts. Cotton absorbs water, keeping the area moist and creating more irritation. Lubrication and nipple protection with surgical tape or bandages are also good options. Infectious diseases may also be more problematic for endurance athletes, as the constant wet environment in runners and swimmers results in maceration, which is an ideal environment for fungal growth.


What about the infectious conditions?

Infectious dermatoses are common among almost all sports categories. They are facilitated through contact (contagion), traumatic wounds (skin barrier disruption), irritation (fragile skin barrier), sweating, and heat (favorable environment for microorganisms’ growth). They are particularly problematic in resistance sports, such as contact sports like wrestling and judo, due to the amount of time athletes spend in direct skin-to-skin contact with other athletes, making them prone to transmission of viral, fungal, and bacterial infections. The most common are tinea pedis and tinea corporis. Tinea pedis is more prevalent in running, swimming, soccer, water polo, and basketball. Occlusive footwear is a major culprit as the responsible microorganisms (dermatophytes) thrive with sweating and maceration.

Prevention should include wearing moisture-wicking synthetic socks and changing them regularly, keeping the feet dry, wearing well-ventilated shoes, using antifungal powder, and always using sandals in the locker room and on the pool deck. Prevention includes not sharing bath towels, wearing shoes in the shower, drying out the skin after showering (especially toes), wearing new clean cotton socks daily, and letting sports shoes dry for 24 hours.

Can sport aggravate certain pre-existing dermatoses?

Absolutely. Practice and competition can aggravate pre-existing dermatoses (in particular, atopic eczema and physical urticaria). The skin must be prepared because there is always a risk of aggravation during competition. The skin barrier must be protected by implementing a good skincare routine many weeks or days before the competition (not the day before). Overall, eczema and dry skin are very frequent in the sporty population. This is accentuated by frequent washes, irritating products, sweating, and irritation induced by skin friction. Sometimes, when the skin barrier is compromised, the penetration of environmental allergens is facilitated, inducing skin allergies. The population most at risk are swimmers.

For sports activities, I recommend avoiding wearing irritating clothing fibers such as wool, linen including cotton and prefer synthetic materials that favor sweat elimination. In daily life however, cotton and silk are better options as being more gentle and less irritating.

Tell us more about the environmental dermatoses.

Some sport dermatoses can be triggered or exacerbated by various elements encountered during sporting activities such as cold, heat, water, and sun exposure. This won’t be the case during the summer Olympics. Still, mountaineers or skiers who have to compete for long periods of time in extreme cold conditions are at risk of frostbite, which corresponds to the freezing of tissues, sometimes with irreversible damage. You need to warm up the skin quickly with warm water, without massaging or rubbing. Heat can also incapacitate, triggering urticaria, a kind of heat rash. It’s important to let the skin breathe, moisturize it well, and choose clothing that allows perspiration to pass through.

Aquatic dermatoses are specific to aquatic sports (on or in the water) and the environment (swimming pool, freshwater, or seawater), with potentially pathogenic microorganisms depending on the aquatic environment. Divers and synchronized swimmers, like other aquatic athletes, can develop contact dermatitis: irritant from the chemicals (chlorine and bromine) in the pool, or allergic to nose clips, ear plugs, swimming caps, goggles, or pool water. They are also prone to xerosis; pools dilute the skin’s sebum and draw water from it. This xerosis can turn into aquagenic acne, thought to be a rebound of hyperactivity of the sebaceous glands.

Finally, sun exposure concerns all athletes performing outdoors. Due to long training hours in the sun, many athletes experience high levels of UV radiation, which is the most important environmental risk factor for both melanoma and non-melanoma skin cancer development. This is particularly true for endurance athletes, cyclists, triathletes, tennis players, and sailors. Practicing outdoor sports also exposes athletes to the risk of sunburn, of course, but also to reactions to light linked to an underlying disease or a substance in contact with the skin (cosmetics, plants) that creates a burning reaction immediately after UV exposure.

First, I encourage athletes to cover up as much as possible with anti-UV clothes and then apply sunblock on any remaining sun-exposed body skin. I recommend personalized protection based on consulting the UV index associated with the local weather and applying sun care products 30 minutes before going outside. Prefer the use of a water-resistant product. When it comes to organic versus inorganic filters, though I prefer inorganic filters, I leave it to the patients to decide because, at the end of the day, the best protection is the one they will wear and re-apply.

What is the role of skincare in all of this?

A good and simple skincare routine is critical to prevent many sports dermatoses.

—I encourage a 3-step approach:

  1. Gentle (soap-free) body cleansing
  2. Customized hydration for the face and body
  3. Sun protection

—I advocate a minimalist approach regarding skincare formulation, which means a limited number of ingredients in the formula and no fragrance. Because of sweating and skin xerosis induced by frequent showering, the skin is more sensitive and more prone to developing contact allergies. Selecting products with a short list of ingredients should be a priority to minimize the risks of skin reactions.
—I also recommend that my athletes avoid using products in hotels or recommended by friends, sponsors, and family.
—Keep it simple and stick to the routine. This is the best prevention!


Any specific products that you add to the basic skincare routine?

Specific products can be added to the skincare routine depending on the sports dermatoses to be prevented. For example, barrier creams (Vaseline or zinc-based) to avoid friction in fragile areas, and zinc-based absorbent creams to absorb perspiration and prevent maceration. I encourage the use of I often recommend the use of shampoos with chelating agents for swimmers in the pool and even sometimes slightly disinfectant soaps to prevent skin infections in people who tend to practice aquatic or team sports.


Finally, are there any dermatoses that are unique and manifest only in some types of athletes?

Yes, indeed. “Talon Noir,” (black heel) for example. Basketball, soccer, tennis, gymnastics, and running that require frequent starts and stops can lead to talon noir (black heel). They are completely benign and appear as blue-to-black linear, circular macules on the posterior or posterolateral aspect of the heel. “Green Hair” also occurs in water sports athletes with blonde, grey, or white hair prone to pigmentation by copper ions in pools or through the combination of sunlight and chlorinated water. Then there’s “jogger’s nipple“, which we discussed previously.


Anything else that you would like to add?

Do not minimize dermatological problems in athletes because they can be extremely disabling in competition. We tend to say, “It’s not a big deal, it’s just the skin,” when it can dramatically jeopardize performance and achievement.

1. Norrenberg S et al. Dans la peau des sportif.ve.s :dermatologie du sport.Rev Med Suisse 2021 ;17 :1295-300
2. De Luca J et al. Skin Manifestations of athletes competing in the summer olympics sports Med 2012;42 (5).399-413
3. Snyder A et al. Solar ultraviolet exposure in individuals who perform outdoor sport activities. Sports Med Open 2020;6:42