‘Deep’ white superficial onychomycosis due to molds

Systematic review of nondermatophyte mold onychomycosis: Diagnosis, clinical types, epidemiology, and treatment

“…SWO caused by NDMs can be indistinguishable from that caused by dermatophytes (Fig 2), or may appear as a ''deep'' SWO, 25 where nail plate invasion is deep and involves a large part or all of the nail (Fig 3).…”

Superficial white onychomycosis caused by Trichophyton verrucosum

“…Although T. verrucosum may not be as osmotolerant as T. interdigitale , it is more osmotolerant than other species of dermatophyte that have never been reported to cause SWO. Cases of deeper nail involvement have been reported, paradoxically referred to as “deep” SWO, in some cases apparently caused by nondermatophytes that tend to penetrate the nail more deeply or extend beneath the proximal nailfold 8,9 . In our case, T. verrucosum , being a member of the dermatophyte family, invaded only the upper layer of the nail plate, explaining the relatively easy removal of the white material by mechanical scraping.…”

An Idiopathic Leukonychia Totalis and Leukonychia Partialis Case Report and Review of the Literature

“…Fungal invasion of the superficial plate produces punctate areas of leukonychia that can eventually coalesce to involve the entire surface of the nail plate. Non-dermatophytes, which are an uncommon cause of white superficial onychomycosis, can invade into the depths of the nail plate as seen in ‘deep' white superficial onychomycosis [9]. Because the most superficial aspect of the nail plate is always affected, the nail plate texture is often rough and crumbles easily.…”