Treatment of non-dermatophyte, mould onychomycosis

For non-dermatophyte infections - oral itraconazole as a pulsed therapy is recommended (200mg twice daily for 1 week a month for 2 months in fingernail and for 3 months in toenail infections) (1).

Successful treatment of mould nail infections (e.g. infections such as scopulariopsis brevicaulis, Fusarium species, Aspergillus species) may be more difficult than treatment of yeast or dermatophyte infections. Consult microbiologist for advice regarding treatment measures.

• a report on a series of 15 patients treated for onychomycosis secondary to mould infection itraconazole demonstrated efficacy against onychomycosis of the toenails caused by S. brevicaulis and Aspergillus species
• the authors also undertook a review of the literature that confirmed their experience with itraconazole and further suggested that terbinafine may also demonstrate efficacy against cases of S. brevicaulis and Aspergillus toe onychomycosis.
• additionally, reports in the literature suggest that pedal onychomycosis caused by Fusarium species may also show response to itraconazole and terbinafine. For the other species, there are fewer data, making it difficult to draw conclusions.

Notes (1):

• treat only if infection confirmed by laboratory
• only use topical treatment if superficial infection of the top surface of nail plate
• idiosyncratic liver and other severe reactions occur very rarely with terbinafine and itraconazole
• for infections with candida or non-dermatophyte moulds use oral itraconazole
• for children seek expert advice
• treatments available (1,3)
  • 5% amorolfine nail lacquer
    • 1-2x/weekly
    • fingers for 6 months
    • toes for 12 months
  • itraconazole
    • 200 mg BD
    • fingers for 2 courses of 7 days/month
    • toes for 3 courses of 7 days/month

Reference:

• (1) Health Protection Agency 2011. Fungal nail & skin infections: diagnosis & laboratory investigation – Quick reference guide for primary care
• (2) J Cutan Med Surg. 2001 May-Jun;5(3):206-10. Epub 2001 May 02.
• (3) Public Health England 2017. Fungal skin and nail infections: Diagnosis and laboratory investigation - Quick reference guide for primary care.