• Fungal infection of the nail
  • Usually affects toenails, although fingernails can be affected[1]
    • Generally affects multiple nails at once, and usually concurrent tinea pedis is present[2]
  • May be caused by dermatophytes (most common), non-dermatophyte, or candida fungal species

Clinical Features

  • Nail abnormalities[1]
    • Thickened nail plate
    • Discoloration
    • Oncholysis
    • Subungal hyperkeratosis

Differential Diagnosis


  • Generally a clinical diagnosis, based on history and physical examination
  • Microscopic evaluation of an adequate sample will reveal fungal features
  • Many guidelines recommend fungal cultures to ensure proper treatment[1]
    • The three main approaches are potassium hydroxide smear, culture, and histology (involves microscopic examination and culture of nail scrapings or clippings)


  • PO Antifungals (first line)[1]
    • Terbinafine - 250mg QD for 12 weeks (toenail) or 6 weeks (fingernail) - most effective therapy
    • Itraconazole - 200mg QD for 12 weeks
    • "Pulse dosing" may be as effective as continuous dosing
    • Fluconazole and ketoconazole are less effective and should not be used
  • Topical Antifungals
    • Creams are generally ineffective
    • Lacquer preparations are more effective due to longer contact times, but should only be used if fungus covers <50% of nail[1]
    • Ciclopirox 8% - daily application for 4 months
    • Amorolfine 5% - 1-2 times per week for 6-12 months
    • Efinaconazole 10% - newer agent


  • Discharge

See Also

External Links


  1. 1.0 1.1 1.2 1.3 1.4 Leelavathi M, Noorlaily M. Onychomycosis nailed. Malaysian Family Physician : the Official Journal of the Academy of Family Physicians of Malaysia. 2014;9(1):2-7.
  2. Del Rosso JQ. The Role of Topical Antifungal Therapy for Onychomycosis and the Emergence of Newer Agents. The Journal of Clinical and Aesthetic Dermatology. 2014;7(7):10-18.