journal Frontiers in Psychology


1. Introduction {#sec1-jof-03-00020}
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Onychomycosis, a fungal nail infection affecting either the toenails (more common) or fingernails, involving any or all components of the nail structure, is typically chronic and tough to treat. When the causative agent is a dermatophyte, the infection is termed tinea unguium. Common symptoms are thickening of the nails with discoloration, brittleness or deformity and prolonged infection may be accompanied by pain under the nail and while wearing shoes, due to nail thickening or hyperkeratosis. People with these infections have been found to suffer psychosocial stress due to the cosmetic repercussions of an unhealing infection. Tinea unguium due to dermatophytes (*Trichophyton*, *Epidermophyton* species) occurs more often in temperate regions, whereas onychomycosis due to non-dermatophyte moulds and yeasts like *Candida* and *Trichosporon* species are seen more commonly in the tropical regions of the world. Among the non-dermatophyte moulds, the common onychomycosis-causing fungi are *Scytalidium* (or *Neoscytalidium*), *Aspergillus*, *Fusarium*, *Scopulariopsis*, *Paecilomyces*, *Pseudoallescheria*, *Penicillium* and *Alternaria* species. Rarer species implicated are *Onychocola* species, *Pyrenochaeta* species, *Chaetomium globosum* and *Lasiodiplodia theobromae*. All fungi involved exhibit keratinolytic activity \[[@B1-jof-03-00020],[@B2-jof-03-00020],[@B3-jof-03-00020]\]. Some studies have stressed the significant prevalence of non-dermatophyte fungi (NDF) in onychomycosis. A 2015 study showed non-dermatophyte moulds emerging as a leading cause of onychomycosis in south-east Rajasthan in India \[[@B4-jof-03-00020]\]. In 2016, a growing incidence of non-dermatophyte onychomycosis was reported from Tehran, Iran with *Aspergillus* as the most common cause, followed by *Fusarium* \[[@B5-jof-03-00020]\]. NDF have also been seen to colonize damaged nail plates \[[@B6-jof-03-00020]\].

Predisposing risk factors to onychomycosis i