Onychomycosis

Background

• Fungal infection of the nail
• Usually affects toenails, although fingernails can be affected
• May be caused by candida, dermatophytes, or non-dermatophyte fungal species

Oncyomycosis

Clinical Features

• Nail abnormalities
  • Thickened nail plate
  • Discoloration
  • Oncholysis
  • Subungal hyperkeratosis

Diagnostic Evaluation

• 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

Management

• PO Antifungals (first line)
  • Terbinafine - 250 mg QD for 12 weeks (toenail) or 6 weeks (fingernail) - most effective therapy
  • Itraconazole - 200 mg 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
  • Ciclopirox 8% - daily application for 4 months
  • Amorolfine 5% - 1-2 times per week for 6-12 months

Disposition

• Discharge