Both acute and chronic toenail injuries are common among athletes. While the symptoms of acute injuries such as subungual hematoma and paronychia lead patients to seek prompt treatment, chronic nail injuries can go untreated for years. Several sports including ballet, rock climbing and skiing require tight-fitting footwear, which predisposes athletes to toenail injuries.
Additionally, sports that involve travel on steep and irregular terrain, such as trail running, hiking and mountaineering, put the nail bed at risk due to shear forces and contusion of the toenails as the foot migrates to the end of shoe gear. The most common chronic toenail injuries in athletes are traumatic onychodystrophy and onychomycosis.
Trauma as well as persistent microtrauma to the nail apparatus can lead to several of the following chronic pathologic changes of the nail bed.
• Subungual orthokeratotic keratinization is formation of a nulcear keratin layer below the nail plate.1
• Lichen simplex chronicus of the nail unit is thickening of the skin of the nail unit with variable scaling that results in secondary to repetitive scratching or rubbing.1
• Onychauxis is pathologic keratinization of the nail bed and/or thickening of the nail complex.2,3
• Onycholysis is pathologic detachment of the nail plate from the nail bed.2,3
• Onychoclavus is hyperkeratosis under the distal nail margin.2,3
• Onychophosis is local or diffuse hyperkeratosis to the nail folds resulting from repetitive microtrauma.2,4
• Onychogryphosis is enlargement and thickening of the nail plate.2-4
The treatment for traumatic onychodystrophic nail changes includes mechanical prevention of nail apparatus trauma with activity modification, orthotics and shoe gear accommodation, manual nail plate debridement and chemical nail plate debridement (47% urea nail gel, Kera Nail Gel, Clinical Therapeutic Solutions).1,5 Research has shown that the use of topical glucocorticoids in the proximal nail fold is successful in treating lichen simplex chronicus of the nail unit.6 Topical keratolytics including 40% urea, lactic acid 12% and salicylic acid 6-20% can effectively treat hyperkeratosis of the nail folds.7 Surgical or chemical matrixectomy are treatment options for nail changes that fail to respond to more conservative treatment modalities or that cause significant pain and/or dysfunction.8
Athletes encounter numerous risk factors for the development of fungal nail infections, including heavy perspiration, moist environments, going barefoot in public places such as gyms and swimming pools, tinea pedis infection, minor skin and nail injury, and traumatic damage to the nail. Both traumatic nail injuries and traumatic onychodystrophy can serve as precursors to the development of onychomycosis. Given the similar appearance of onychomycosis and traumatic onychodystrophy, authors recommend nail biopsy with KOH preparation, periodic acid Schiff (PAS) staining or fungal culture for accurate diagnosis and appropriate treatment.9
The majority of fungal nail infections are due to the dermatophytes Trichophyton rubrum, Trichophyton mentagrophytes and Epidermophyton floccosum. The gold standard treatment for onychomycosis is systemic antifungal medication. This includes the oral medications terbinafine (Lamisil, Novartis), itraconazole (Sporanox, Janssen Pharmaceuticals), fluconazole (Diflucan, Pfizer) and griseofulvin (Grifulvin V, OrthoNeutrogena).10
Topical ciclopirox nail lacquer is currently the best topical available for the treatment of onychomycosis but has less than a 9 percent complete clearance rate.11 Ciclopirox can serve as an adjunct to oral treatment or as monotherapy for the treatment of mild to moderate onychomycosis without lunula involvement.11
The FDA recently approved non-ablative lasers for the temporary clearing of mild to moderate onychomycosis and laser treatment is frequently an attractive treatment modality for athletes who wish to avoid systemic medication.12
Both traumatic onychodystrophy and onychomycosis are common chronic nail pathologies in athletes. Identifying the underlying cause, trauma or infection will enable one to target the correct nail disorder with the appropriate treatment.
1. Bako Pathology Services. Nail Plate Biopsy Report. Available at http://www.bakopathology.com/our-services/podiatric-pathology-services  . Accessed April 3, 2014.
2. Cohen PR, Scher RK. Aging. In: Hordinsky MK, Sawaya ME, Scher RK, editors. Atlas of hair and nails. Churchill, Philadelphia, 2000, pp. 213-225.
3. Allevato MAJ. Diseases mimicking onychomycosis. Clin Dermatol. 2010; 28(2):164-177.
4. Vlahovic TC, Schleicher SM. Nail Disorders. In: Skin Disease of the Lower Extremities: A Photographic Guide, Chapter 1. HMP Communications, Malvern, PA, 2012, pp. 19-20.
5. Helfand AE. Nail and hyperkeratotic problems in the elderly foot. Am Fam Physic. 1989;39(2):101-10.
6. Khoo BP, Giam YC. A pilot study on the role of intralesional triamcinolone acetonide in the treatment of pitted nails in children. Singapore Med J. 2000;41(2):66-68.
7. Cohen PR, Scher RK. Geriatric nail disorders: diagnosis and treatment. J Am Acad Dermatol. 1992;26(4):521-31.
8. Baran R, Dawber RPR. Physical signs. In: Baran R, Dawber RP (eds). Diseases of the nails and their management, second edition. Blackwell Science, Oxford, 1994. pp. 35-80.
9. Rich P. Nail biopsy: indications and methods. Dermatol Surg. 2001; 27(3):229-34.
10. Shemer A. Update: medical treatment of onychomycosis. Dermatol Ther. 2012;25(6):582-93.
11. Gupta AK, Fleckman P, Baran R. Ciclopirox nail lacquer topical solution 8% in the treatment of toenail onychomycosis. J Am Acad Dermatol. 2000; 43(4 Suppl):S70-80.
12. United States Food and Drug administration medical device approval (K103626). Available at http://www.accessdata.fda.gov/cdrh_docs/pdf10/K103626.pdf  .