Infections and Infestations Associated with Sports
Individuals who participate in athletic pursuits may be at higher risk for certain infections and infestations. Here’s how to recognize and treat them.
The mention of sports dermatoses may conjure images of elite runners hampered by a raging presentation of tinea pedis or a high school wrestler sidelined by a case of herpes gladiatorum. However, the range of common dermatoses associated with sports can affect individuals at all levels of fitness and competitive performance and at any age (these very same conditions can present wholly unrelated to sports, as well). The list of sports that may be associated with cutaneous insult or injury includes but is not limited to football, baseball, basketball, track and field, golf, bowling, tennis, soccer, hockey, and winter sports, like ice skating or skiing.
Among the most frequent skin complaints to affect sports enthusiasts are infections and infestations, including dermatophytoses and bacterial infections. In this first in a series of articles addressing sports dermatoses, I address bacterial, fungal, viral, and parasitic infections and infestations.
Community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are now common across the country. In my own practice, annually since 2004, the proportion of all bacterial cultures testing positive for CA-MRSA has consistently been seven to eight percent (19-27 percent of cultures positive for S. Aureus). Studies have shown high rates of MRSA colonization among collegiate1 athletes, while other investigations have failed to show that rates of carriage are higher among college or high school athletes compared to the general population.2,3 Nonetheless, the Centers for Disease Control and Prevention (CDC) have identified clusters of CA-MRSA infection among competitive sport participants, likely facilitated through skin-to-skin contact, traumatic damage to the skin, and sharing of clothes and equipment.4
The classic presentation of MRSA is an abcess or furuncle that may mimic a spider or insect bite. Incision and drainage is standard of care (with adjunctive oral antibiotics when indicated) for abcesses. 5 Abcesses may be accompanied by cellulitus, or cellulitus may develop on its own. Alternatively, another common presentation is CA-MRSA folliculitus. 6,7 Body shaving, common among swimmers and also prevalent in other sports, may contribute to the development of folliculitus. Systemic treatment is indicated for MRSA-associated cellulitus or folliculitus with adjunctive topical antibacterial therapy initiated to help reduce colonization.
Often trimethoprim/sulfamethoxazole is identified as the first-line systemic antibiotic of choice, however tetracyclines are effective against CA-MRSA.8,9 In fact, in one series of CA-MRSA cases from Kentucky, all isolates were sensitive to trimethoprim/sulfamethoxazole (TMP/SMX), tetracycline, and rifampin, while only 83 percent of those tested for clindamycin, 50 percent of those tested for levofloxacin, and none tested for cefazolin were sensitive to the given antibiotics.9 Both doxycycline and minocycline are effective, safe, and inexpensive for the treatment of CA-MRSA. Recommended dosing is 100mg bid for 10 days. Minocycline may be a better choice due to its lipophilicity, which may more effectively target the nasal mucosa.
Good hygiene is encouraged to reduce the transmission of CA-MRSA. Also essential are strategies to avoid sharing equipment, clothing or towels, disinfection of possibly contaminated surfaces (including locker room surfaces), and limiting direct skin-toskin contact as much as possible.
Athletes who use hot tubs may be susceptible to cutaneous Pseudomonas aeruginosa infection or “hot tub folliculitus,” particularly if the water is not properly chlorinated/bromated. Pseudomonas folliculits is characterized by a maculopapular, pustular, usually non-pruritic rash.
Pseudomonas folliculitus is expected to resolve spontaneously,10 although systemic antibiotic therapy is typically administered. Of note, a recent analysis of P. aeruginosa isolates from swimming pools and hot tubs found that 96 percent of samples were multi-drug resistant.11
Dermatophytoses are prevalent, prompting well over four million physician visits annually in the US.12 In the general population of the US, data suggest that onychomycosis is most common (23.2 percent of all dermatophytoses), followed by tinea corporis (20.4 percent), tinea pedis (18.8 percent), tinea capitis (15 percent), and tinea cruris (8.4 percent).12 Reliable recent data for disease prevalence among athletes are not available, though it seems from clinical experience that superficial cutaneous infections—tinea pedis, tinea cruris or “jock itch,” tinea corporis, tinea faciale, and tinea manus—are more common complaints among athletes than is onychomycosis. Consider that the term “tinea gladiatorum” has been applied specifically to tinea corporis caused by the dermatophyte Trichophyton tonsurans in competitive wrestlers.13 And in one recent survey, 69 percent of professional soccer players, 69 percent of male college soccer players, and 43 percent of female college soccer players were found to have tinea pedis, compared to just 20 percent of male non-athletes and none of the female non-athletes.14
Several factors contribute to the increased incidence of dermatophytoses in athletes. Dermatophytes thrive in the moist environments that perspiration creates in skin folds and interdigital skin spaces or athletic equipment.Furthermore, there may be enhanced opportunity for the spread of infection between sport enthusiasts: Athletic shower rooms are a confirmed source of dermatophyte infections.15 Additionally, dermatophytes may colonize footwear or other athletic equipment that may be shared by individuals. Improperly laundered towels, socks, or other items may harbor dermatophytes and facilitate infection spread.16
Rarely does the diagnosis of tinea pose challenges for the clinician. Treatment, however, can be a different matter. Most cases of dermatphytosis can be managed with topical antifungals (Table 1). Oral antifungals typically are reserved for extensive or chronic involvement or when application of a topical agent is physically challenging for the patient.17 Treatment must be selected that is expected to address the causative organism and in a vehicle formulation that the patient can easily apply to the treatment site. A broad-spectrum antifungal is preferred and is especially important in the case of inflammatory, malodorous presentations of tinea pedis, because the conversion from a scaling, erythematous presentation to a more macerated, malodorous, symptomatic process indicates that bacteria have proliferated.18
Allergic contact dermatitis of the feet or hands may mimic tinea pedis or manuum, respectively, and must be considered in the differential diagnosis. Of note, a dermatitis that develops on both hands and both feet is more likely to have a systemic cause rather than to be an allergic contact dermatitis.19 Conversely, involvement of two feet and one hand suggests a primary fungal infection of the foot that has been transferred to one hand only.20 Why the other hand is not involved is still a puzzlement.
Strategies to prevent recurrence or subsequent infection are as important as medically treating the dermatophytosis, though some proposed strategies may be unrealistic for patients. (See sidebar.) Simple preventive strategies have been shown effective. Wearing clean socks (but not stockings) was shown to prevent passage of dermatophytes from colonized shoes to the feet.21 In addition to wearing shower shoes, individuals with healthy feet who use public showers should wash the feet with soap and carefully wipe and dry the feet to remove any adherent dermatophytes. 21 Laundering at temperatures of 140 degrees F or higher can remove or kill T. rubrum and C. albicans.16 This is a standard temperature for home water heaters, so residential washing machines can achieve this temperature. Permitting shoes to dry thoroughly before wearing them again may also be effective for reducing dermatophyte transmission.
Prophylactic topical antifungal therapy applied at intervals may be indicated for those at high risk for or with a history of recurrence of dermatophytosis.
Tinea pedis or manuum may provide a reservoir of dermatophytes leading to onychomycosis, though in some cases nail involvement is a primary presentation. Development of topical therapies for onychomycosis has proven challenging, due to the difficulty of penetrating the nail plate to deliver drugs to the nail bed, the site of infection. Therefore, systemic antifungal therapy has been the mainstay of treatment. Although systemic terbinafine and itraconazole are shown to be effective and generally safe for the management of onychomycosis, 22 there are potential risks associated with therapy.23 Given this albeit very low risk, some patients, especially the young and the elderly, prefer to avoid or postpone systemic therapy. For distal subungual onychomycosis, a topically applied, low-viscosity, alcohol-based antifungal solution (sulconazole nitrate 1%, Exelderm, Ranbaxy Laboratories) may offer benefit when properly applied. Therapeutic success requires that the patient deliver the solution directly into the nail bed by placing the toe or fingernail in an upright position then instilling one to two drops subungually between the nail plate and nail bed. The patient should hold the toe or finger in an upright position for 30 seconds, to allow gravity to pull the active agent into the nail bed. Treatment should be applied twice daily. Coexistent tinea pedis or manuum must be managed to minimize the risk of re-infection of the nail.
Superficial cutaneous yeast infections may be predominantly caused by Candida. Among immunocompetent individuals, candidiasis may be especially common in the inframammary folds or genital crease region (more so for women than men). Culture can be used to distinguish Candidiasis from dermatophytosis. Topical antimycotics are standard treatment for candidiasis, particularly clotrimazole or ketoconazole. Oral fluconazole is the primary systemic agent with anti-Candida activity.
Another yeast infection that may affect athletes is Malassezia folliculitus (previously called pityrosporum follicultius). Papulopustules are found in a follicular pattern on the back, chest, upper arms, and, occasionally the neck, and face into the scalp.24 Monomorrphous erythematoid papulpustules measure 1-2mm in diameter and are frequently misdiagnosed as acne vulgaris. The yeast is ubiquitous on the skin and its growth is encouraged by heat. Moisture, friction, occlusion, sweating and increased oil prouction appear to contribute to exacerbation.
Non-genital herpes simplex presentations occur most frequently in the general population in the form of herpes labialis; other body sites may be affected, especially in the athlete. The presentation of grouped vesicles or ulcers on an erythematous base along with patient history are key to diagnosis. The differential diagnosis of nongenital herpes simplex virus infection includes aphthous ulcers, acute paronychia, varicellazoster virus infection, herpangina, and Behçet syndrome. 25 If there is any doubt about the diagnosis, standard tests to confirm the diagnosis of HSV include viral culture, polymerase chain reaction, serology, direct fluorescent antibody testing, or Tzanck test.
Herpes simplex infection of the body or herpes gladiatorum (HG), is prevalent among wrestlers as well as rugby players and potentially other athletes with high rates of physical skin-to-skin contact.26 Any individual found to have HG should be suspended from competition for an appropriate period to reduce the risk of transferring HSV, usually until the vesicles have crusted. Specific guidelines are available from sport governing bodies regarding suspension durations.
Antiviral therapy with Valacyclovir (Valtrex, GlaxoSmithKline) or famciclovir (Famvir, Novartis) is indicated in individuals with active HSV (See prescribing information for dosage and age guidelines). Competitors with recurrent HSV or a history of HSV may be treated prophylactically with oral antiviral therapy administered seasonally, which was shown to reduce the risk of HSV spread among competitive wrestlers.27
Given the rate of close contact in many team sports, participants are at risk for spread of parasitic organisms, such as Sarcoptes scabiei, the causative organism of scabies.28 Sarcoptes scabiei have been somewhat understudied, though new investigations are providing a better understanding of the organism and possible treatment.29 Affected body sites most often include the finger webs, wrists, axillary folds, abdomen, buttocks, inframammary folds and, in men, the genitalia. Diagnosis is confirmed through microscopic visualization of the scabies mites or their eggs or fecal pellets.30 Topical treatment with benzyl benzoate or permethrin offers reasonable efficacy but rarely provides complete cure.31 Oral ivermectin provided at a dose of 200micrograms/k provided one week apart has been shown to provide near 100 percent efficacy.30,31 The agent is not approved for this use in the US.
Win the Fight Against Infections/Infestations
Any of the presentations described above may be associated at least with pruritus, discomfort, and a host of other symptoms that would be bothersome for any individual. In the athlete, these conditions may impede performance or even prevent participation in competitive sports. Clinicians should be prepared to identify, treat, and help the patient prevent infections and infestations.
Both doxycycline and minocycline are effective, safe, and inexpensive for the treatment of CA-MRSA. Pseudomonas folliculitus is expected to resolve spontaneously; systemic antibiotic therapy is typically administered. Most cases of dermatphytosis can be managed topically. Allergic contact dermatitis of the feet or hands may mimic tinea and must be considered in the differential diagnosis. Malassezia folliculitus (previously called pityrosporum follicultius) is frequently misdiagnosed as acne vulgaris. Antiviral therapy is indicated in individuals with active HSV. Competitors with recurrent HSV or a history of HSV may be treated prophylactically.
A dermatitis that develops on both hands and both feet is more likely to have a systemic cause rather than to be an allergic contact dermatitis.19 Involvement of two feet and one hand suggests a primary fungal infection of the foot that has been transferred to one hand only.20
Realities and Practicalities of Preventing Dermatophyte Spread
Some strategies found to be effective for eradication of dermatophytes may not be realistically implemented. For example, one study showed that leaving the feet upright and exposed to the air destroyed adherent dermatophytes.15
It has long been recommended that individuals with recurrent tinea pedis or a previous history of tinea pedis avoid wearing shoes or opt for minimally occlusive shoes, such as sandals, whenever possible. Again, this seems straightforward but may not be an option for some individuals.
Evidence regarding the best ways to disinfect shoes is potentially confusing. Studies showed that pouring either cold or boiling water into sandals or sneakers or wiping out sandals or sneakers with a wet towel was effective in removing dermatophytes, yet these strategies were not effective for boots.21
Dr. Bikowski has served on the speaker's bureau or advisory board or is a shareholder or consultant to Coria and Ranbaxy.
Joseph Bikowski, MD is Clinical Assistant Professor of Dermatology at Ohio State University in Columbus, OH and Director of Bikowski Skin Care Center in Sewickley, PA.
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