Wood's lamp was demonstrated to be useful in three cases of dermatophytoma treated during clinical dermatological practice. Clinical signs of onychomycosis are longitudinal yellow and white striae on the nail plate and are diagnosed by KOH direct microscopic examination. For its treatment, surgical debridement is recommended. Usefulness of the Wood's lamp for diagnosis of tinea capitis caused by Microsporum canis is standard. In the first and second cases, we used Wood's lamp (Woody™) to make a clear margin for debridement of onychomycosis. In the third case, onychomycosis was unsuccessfully treated using topical 5% luliconazole nail solution for 1 year and 10 months with yellow nail discoloration. Under Wood's lamp, we were able to distinguish luliconazole crystal staining from onychomycosis. This method is simple and quick, and useful for nail observation in dermatology clinics.
The incidence of non-dermatophyte mould onychomycosis has been increasing worldwide for the past several decades, but it is not well recognized in Japan. Recent molecular techniques and phylogenetic analyses contributed to the identification of uncommon and emerging species. We came across 13 (0.5%) cases of non-dermatophyte onychomycosis among a total of 2,591 onychomycosis cases in 106,703 outpatients during the past 5 years (January 2015-December 2019). The cases included 5 patients with Aspergillus species, 4 patients with Fusarium species, and one patient each with Scopulariopsis brevicaulis and Botryosphaeria dothidea, respectively. Botryosphaeria dothidea is closely related phylogenetically to Neoscytalidium dimidiatum. In Japan, at the time of writing this report, there are 26 reported cases of ungual aspergillosis and 18 cases of hyalohyphomycosis caused by Fusarium species. We summarize these cases and report the symptoms and mycological features.