for Health Care Providers

Onychomycosis

Type	Findings/ Distribution	Diagnostic Clues	Management
* See Potential ARV Interactions, below, and Common Medications.
Distal subungual onychomycosis (see photo in DermAtlas) Infection with Trichophyton rubrum in vast majority of cases	Affects great toe first; can affect all toes Begins with discoloration of distal corner of nail, spreads across nail, then extends toward cuticle Distal nail plate can break off, becoming heaped and irregular	Culture: most sensitive and specific KOH preparation: clip or file nail-plate and collect scales from most proximal area Look for hyphae and arthrospores Low sensitivity and specificity, but up to 100% sensitive if >2 preparations examined If negative, consider biopsy for histopathology	Indications for treatment: cellulitis, pain, patient desire for treatment Oral therapies* (in order of decreasing efficacy), pulse dosing: Terbinafine 250 mg QD for 1 week each month Itraconazole 200 mg QD for 1 week each month Fluconazole 150 mg once weekly Treat 2 months (fingernails), 3-4 months (toenails) Fluconazole 400 mg once weekly for 6 months has shown efficacy in immunocompromised patients; fluconazole has fewer drug interactions than itraconazole Cure rates range from 76% with terbinafine to 48% with fluconazole Topical therapies generally ineffective; ciclopirox topical nail lacquer can be used with patients who cannot safely take oral therapy; trials show 7% cure rate Surgery: removal of nail in isolated nail infection or dermatophytoma See Potential ARV Interactions, below, and Common Medications.
Proximal subungual onychomycosis Trichophyton rubrum most common Marker of HIV infection, immunocompromised state	Discoloration begins at cuticle and extends distally	Same as above	Same as above
White superficial onychomycosis Trichophytonmentagrophytes most common	Starts as dull white spots, then spreads centrifugally	White areas are soft and can be scraped with a curette for culture or KOH slide	Same as above
Candida onychomycosis Candida albicans More common in patients with HIV infection	Common cause of fingernail infection Often in previously damaged nails Rarely in toenails Nail thickening and discoloration Can lead to onycholysis	Fingernail scraping should be sent for culture of yeast	Oral therapies (in order of decreasing efficacy), pulse dosing: Itraconazole 200 mg QD for 1 week each month Terbinafine 250 mg QD for 1 week each month Treat 2 months (fingernails), 3 months (toenails)
Mold (eg, Aspergillus, Scopulariopsis)	Rare cause of toenail infection	Consider when dermatophyte infection is ruled out	Oral therapies (in order of decreasing efficacy), pulse dosing: Itraconazole 200 mg QD for 1 week each month Terbinafine 250 mg QD for 1 week each month Treat 2 months (fingernails), 3 months (toenails)

From Dermatologic Conditions
Primary Care of Veterans with HIV
Office of Clinical Public Health Programs
Veterans Health Administration, 2009