Dermatophytes: fungal infections of the skin, nails and hair

It is, perhaps, an unpleasant thought, but our feet can harbour nearly 200 fungal species.¹ More than 30 species of dermatophyte can cause superficial infections of nails, skin and hair.² Dermatophytes are exquisitely well adapted to their hosts and before contemporary treatments, ringworm lasting for 20 years or more was ‘not uncommon’.³ Modern antifungals treat most dermatophyte infections relatively rapidly, although resistance is increasing and new threats continue to emerge.^1,2,4 

So, don’t underestimate dermatophytes. Toenail onychomycosis (fungal nail infections), for example, may make walking painful and buying comfortable shoes difficult.⁵ Onychomycosis patients often develop subungual hyperkeratosis: keratinocytes accumulate under the nail plate, which may lift and detach (onycholysis). Unless treated, the nail plate thickens and crumbles.⁵ More severe onychomycosis may cause ridging, ingrown nails and, occasionally, bleeding and nail loss.^5,6 Onychomycosis may also allow secondary bacterial infections, which could increase the risk of foot ulcers in people with diabetes.⁷ Yet, as a new book, What If Fungi Win? by Arturo Casadevall and Stephanie Desmon, warns: ‘We have a huge blind spot when it comes to the diseases and toxins fungi can wield’.¹