Epidemiology

5% of onychomycotic infections are due to mixed infections (1)

Exotic fungal species may result after foreign travel, and normally non-pathogenic organisms may be found causing disease in immuno-compromised patients.

Onychomycosis accounts for approximately 50% of reported nail disorders:

• population-based prevalence of onychomycosis as 4.3% in Europe and North America and found it was more prevalent in men in North America and Europe and in women in South America (2)
• onychomycosis is more common in toenails than in fingernails - toenail infections to be 10 times more common than fingernail infections
• evidence suggests infection was most commonly caused by the dermatophyte fungal organism Trichophyton rubrum (44.9%), followed by yeasts (21.2%), other dermatophytes (20.1%), and moulds (13.3%) (2)

Reference:

• (1) Roberts DT, Taylor WD, Boyle J. Guidelines for treatment of onychomycosis. British Journal of Dermatology 2003;148:402–410
• (2) Foley K et al. Topical and device-based treatments for fungal infections of the toenails. Cochrane Systematic Review. 16 January 2020