How do you approach patients with onychomycosis that does not respond to terbinafine and prolonged courses of fluconazole?

Terbinafine is usually effective in the treatment of the most common nail infections. Failure of treatment with terbinafine and fluconazole should make us consider bacterial co-infection or other non-dermatophyte organisms (i.e., aspergillus or non-C albicans). Fungal cultures are often falsely nega...

The vast majority of patients with mycologically confirmed onychomycosis will obtain complete cure with terbinafine. If a patient fails terbinafine, I would recommend performing culture or PCR to confirm the identity of the organism.