Infectious Disease Compendium

Onychomycosis

Diagnosis

Chronic fungal infection of the nail beds. Culture scrapping or nail clippings.

Epidemiologic Risks

Having nails.

Microbiology

Trichophyton mentagrophytes, Trichophyton rubrum, Trichophyton soudanense, and Candida are most common pathogens.

Empiric Therapy

Topical therapy from NEJM (PubMed):

Nail- For superficial white onychomycosis or fungal infection limited to the distal third; continued until there is no evidence of residual viable fungus, use Amorolfine 5% lacquer (Loceryl and Curanail, not available in the United States) once or twice a week for 6 to 12 months OR Ciclopirox olamine 8% lacquer (Penlac) daily for 48 weeks OR Tioconazole 28% paint (not available in the United States) twice daily for 6 to 12 months.

Onychomycosis: terbinafine 250 mg po qd for 6 weeks.

Fingernails: itraconazole 400 mg/day x 1 week each month for 2-3 months OR fluconazole 200 mg po q wk x 8-16 weeks.

Toenails: terbinafine 250 mg po qd x 12 weeks OR itraconazole 400 mg/day po q week each month for 2-4 months OR fluconazole 200 mg po q wk x 12-24 weeks. A meta-analysis suggests terbinafine is more better than intermittent itraconazole for mycological cure of toenail onychomycosis (PubMed).

Pearls

Rants

I think the risks of drug toxicity (mostly hepatitis) and cost make treatment silly unless your patient is a professional hand or foot model.

ICD9 Codes (Soon to be supplanted by ICD10)

Onychomycosis 110.1; finger or toe 110.1