Cover me! Understanding dermatology in Sports and Exercise Medicine – part II

Dermatoses describe any skin defect or lesion on the skin, and clinicians categorize them according to etiology. Furthermore, clinicians may divide dermatoses into two groups, those caused by or those aggravated by sports. In part II, Nella Grilo discusses dermatoses aggravated by sports and identifies how they can directly or indirectly affect athletes’ health and performance during competitions.

Athletics – TCS New York City Marathon – New York, United States – Runner crosses the Verrazano Narrows Bridge over New York Harbor during the marathon REUTERS/Brendan Mcdermid

Competitive athletes endure extreme physical stress when participating in sports. An athlete’s skin is particularly susceptible to a wide array of repetitive physical and environmental stressors that challenge the skin’s protective function(1,2). Many dermatoses are common in athletic populations due to countless hours of intense physical training, but clinicians frequently misdiagnose or ignore these conditions. Athletes can prevent many of these conditions by using appropriate sports clothing, well-fitting shoes, and practicing good hygiene.


Dermatoses etiology

  • Skin infections
  • Frictional dermatoses
  • Trauma induced dermatoses
  • Dermatoses due to exposure to ultraviolet radiation
  • Thermal injuries
  • Water-related dermatoses
  • Dermatoses due to use of performance-enhancing drugs
  • Aggravation of pre-existing dermatoses
  • Inflammatory conditions


Subungual hematoma

Subungual hematomas are common conditions caused by changes in direction (COD) in tennis and other sports, such as running. The repeated COD causes the toe to push against the shoe toe box and result in trauma underneath the toenail. The resultant hematoma gives the nail a black or red color. In addition, the hematoma causes a build-up in pressure and pain (see figure 1).

Figure 1: Subungual hematoma

Jogger’s Nipples

The skin on the nipple is thin and sensitive and thus prone to irritation. Friction between clothing and the nipple causes fissuring of the nipple and most commonly occurs in long-distance runners. This can occur at any time of the year, but it is more common in cold weather as the nipples become erect.

Talon Noir

Talon noir is calcaneal petechiae due to trauma from shear forces leading to intraepidermal hemorrhage. Talon noir tends to affect the posterior heel and lateral foot. Athletic events often produce lateral shearing forces that cause tearing of blood vessels in the papillary dermis. This creates punctate papillary dermal hemorrhages, leading to extravasation of blood into the epidermis and intracorneal retention of hemoglobin. Basketball, lacrosse, football, soccer, and cross-country running are frequent causes of talon noir. The concern with these lesions is that they can be mistaken for acral melanomas if the history of trauma is not confirmed. Dermoscopy is valuable to distinguish between the two(4).

Tache noir

Tache noir is similar to talon noir; however, it occurs on the palmar surface. It occurs in tennis players, weightlifters, racquetball and baseball players, gymnasts, and golfers(5).

Swimmer’s xerosis

Swimmer’s xerosis, or dry skin, is common among swimmers. Dilution and melting of the natural protective skin sebum lead to moisture loss from the stratum corneum, which results in dry, scaly, and itchy skin(6).

Herpes gladiatorum

Herpes gladiatorum is a viral skin infection caused by Herpes Simplex virus type 1 (HSV1) and spreads by direct skin-to-skin contact. Sports that involve close contacts, such as rugby and wrestling, are a potential risk for spreading the infection. Common names for the disease include ‘wrestlers herpes’ or ‘mat pox.’ Athletes usually begin to experience symptoms within about eight days after exposure. They include fever, swollen glands, a tingling feeling at an affected area, and a cluster or clusters of clear, fluid-filled blisters surrounded by red skin. The blisters may or may not be painful. Diagnosis is clinical, but clinicians can take a biopsy to confirm if in doubt. Once an individual is infected, the infection is life-long. The virus can reactivate at any time and be transmitted to others, even if there are no symptoms.

Corns and calluses

Corns and calluses are thick, hardened layers of skin (hyperkeratosis) that occur in response to trauma. Pressure leads to corns, and friction causes calluses. Corns are typically more painful than calluses; however, both may occur in the same patient(7). The causes of corns and calluses include improper footwear, changes in the anatomy of the toes/foot, changes in gait, or vigorous exercise.

Friction blisters

Friction blisters lead to pain, infection, and complications such as cellulitis and sepsis if not appropriately managed. Over 400,000 people participate in a marathon distance running event in the United States every year, and up to 39% of marathon runners experience a blister during the race(8). With such a high incidence and potential for disability, one would think that the prevention of friction blisters would be better understood. However, friction blisters remain at the mercy of myths regarding prevention and treatment. Physicians, coaches, and athletic trainers continue to advocate using petrolatum jelly and skin powders to prevent blisters; however, these measures may increase the chance of blistering on the feet.

Piezogenic pedal papules

Piezogenic papules are soft, skin-colored bumps found on the feet and wrists caused by pressure. They result from herniation of fat through the dermis. Although most often found in long-distance runners, piezogenic papules may occur in athletes participating in sports, such as boxing or gymnastics, where constant pressure around the hand may cause subdermal fat herniation on the wrist or palm. The patient presents with a history of multiple painless bumps on the heel bilaterally, but they are rarely painful (see figure 2).

Figure 2: Piezogenic pedal papules

Athlete’s nodules

Athlete’s nodules are connective tissue nevi which appear as thick dermal masses at sites of chronic trauma. They typically occur on the dorsum of the feet, knees, and knuckles of surfers, boxers, and football players. Recurrent minor blunt trauma and pressure are aetiological factors in this condition(9).

Acne mechanica

This type of acne occurs when sports equipment or clothing traps heat and sweat on the skin. As the equipment or clothing rubs against heated skin, the skin becomes irritated. Players who wear protective gear are susceptible to acne mechanica. For example, shot-putters tend to develop acne to cradle the shot against their necks. Initially, athletes present with small, rough-feeling bumps and appear at protective gear friction sites. The bumps may develop into pimples and sometimes deep acne cysts if athletes do not appropriately care for the friction sites (see figure 3). Acne mechanica tends to clear more quickly than regular acne; however, if persistent after six to eight weeks of treatment, athletes are advised to seek medical assistance (i.e., dermatologist) as prescription acne medications may be necessary.

Figure 3: Acne mechanica

Table 1: The prevention and treatment of direct traumatic sports skin injuries(1,2,3,4,5, 6,7,8,9,10)

Subungual Hematoma●       Ensure that shoes fit properly●       Clean the affected toe with antiseptic and cover with gauze to prevent infection.
●       Keep toenails clipped short (not extended past the toe edge).●       If the pain is severe, a physician may drill a hole in the nail to relieve pressure. In severe cases, clinicians may need to remove the toenail.
●       Tape the big toe and second toe together.
Jogger’s Nipples●       Wear proper-fitting running shirts to reduce friction.●       Chafed nipples should be cleaned with mild soap and dried thoroughly but gently.
●       Apply athletic tape or a lubricant such as petroleum jelly as an extra barrier.●       Athletes can use antibiotic ointments or a cortisone cream such as hydrocortisone to reduce inflammation.
●       Apply talcum powder to absorb moisture.
Talon and Tache Noir●       Wearing good-fitting shoes to reduce friction.●       Resolves spontaneously; however, with complete at 4-6 weeks after cessation of the causative activity.
Swimmer’s xerosis●       Apply an emulsifying ointment onto the skin before entering the water to act as a barrier.●       Small quantities of a mild oil-based soap or soap substitute are preferable to irritating shower-room soap solutions.
●       Limiting the amount of time spent in hot showers and avoiding long soaks in tubs.●       Athletes can apply an oil-based protective emollient immediately after swimming/showering.
●       Topical steroid preparations to treat areas that develop eczema.
Herpes gladiatorum●       Good personal hygiene is essential for preventing the spread of herpes gladiatorum and other skin infections.●       Systemic antiviral medications, either valacyclovir or acyclovir, if symptoms are severe or causing discomfort.
●       Athletes should shower immediately after practice and use their soap, towels, and razors. ●       In primary infections, the recommended dosing includes valacyclovir 1 mg taken daily for 10–14 days or acyclovir 200–400 mg taken five times daily for 10–14 days.
●       Athletes and coaches should clean the equipment after each use.
●       Athletes should be encouraged to wash their hands often and discouraged from picking or squeezing skin lesions because what drains may be very infectious.
●       Athletes should immediately report suspicious skin lesions to their coach or athletic trainer.
●       Cleaning and disinfecting the sports environment (e.g., mats).
Corns and calluses●       Proper footwear accommodates foot anatomy, hammertoes, mallet toes, bunions, edema, etc. ●       Have the corn or callus reduced by a professional.
●       Check for large seams or bumps on your socks or inside your shoes since these cause irritation.
●       Use a foam cushion, pads, or orthotics for extra protection
Friction blisters●       Podiatric physicians should focus on preventive measures when evaluating athletes with a history of friction blisters. Structural abnormalities and biomechanical dysfunction will increase shear stress on sensitive areas of the foot. ●     Cover the blister loosely with a bandage.
●       Proper use of hosiery, shoe insoles, and friction-reducing modalities.●     Use padding to protect blisters; cut the padding into a donut shape with a hole in the middle and place it around the blister. Then, cover the blister and padding with a bandage.
●     Avoid popping or draining a blister, as this could lead to infection. However, if the blister is large and painful, it may be necessary to drain the blister to reduce discomfort.
●     Keep the area clean and covered. Once your blister has drained, wash the area with soap and water and apply petroleum jelly. Do not remove the “roof” of the blister, as this will protect the raw skin underneath as it heals.
Piezogenic pedal papules● Foam rubber foot pads or foam-fitting plastic heel cups.● Restriction of weight-bearing exercise.
● Weight loss.
● Compression stockings
● A consultation with a podiatrist may be helpful.
Acne mechanica● Place clean, soft padding between the equipment and your skin.● Acne medication with salicylic acid often works well, as salicylic acid helps unclog pores.
● Wear moisture-wicking clothes next to your skin.● In severe cases, microdermabrasion or laser therapy can help.
● Wear loose-fitting clothes to prevent heat and sweat from getting trapped on your skin.


Prevention is the key to healthy long-term participation in sports. It requires the education and cooperation of the athlete to minimize these risks and maximize the intended benefits of fitness programs. Ensuring that athletes wear correctly fitting shoes and clothes will go a long way to preventing most conditions. Early diagnosis and basic interventions will ensure that the athlete can continue training and competing with minimal impact on the schedule if lesions occur. Athletes should seek professional assistance early for more complicated lesions.


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  2. Clin Sports Med.2019;38(4):597-618.
  3. Emerg Med J. 2003;20(1):65.
  4. G Ital Dermatol Venereol. 2012;147(1):133-4.
  5. J Am Acad Dermatol 1997; 36: 448–459.
  6. J Am Acad Dermatol 2000;43(2):299-305.
  7. The Foot 14(4):175-184
  8. Br J Sports Med 2004;38(4):498-501.
  9. Sports Med 1990;10(3):198-203.
  10. Smith ML. “Environmental and sports-related skin disease.” In: Bolognia JL, et al. Dermatology. (second edition). Mosby Elsevier, Spain, 2008:1469-76.
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