The "Guidelines for the management of dermatomycosis" of the Japanese Dermatological Association were first published in Japanese in 2009 and the Guidelines Committee of the Japanese Dermatological Association revised it in 2019. The first guidelines was prepared according to the opinions of the Guidelines Committee members and it was of educational value. The revised version is composed of introductory descriptions of the disease concepts, diagnosis, medical mycology and recent advances in treatment, along with clinical questions (CQ), which is intended to help in general practice for dermatologists. The CQ are limited to those involved in therapy but include some of the recently launched antifungal agents. The level of evidence and the degree of recommendation for each item were reviewed by the committee based on clinical studies published by 2018. For rare dermatomycoses, recommendations by the committee are described in the guidelines. In this field, there are still few good quality studies on treatment. Periodic revision in line with new evidence is necessary.

The viability of pathogenic fungi in the scale was investigated during topical administration of 1% luliconazole (LLCZ). Thirteen tinea pedis patients found to be positive on KOH examination were assessed by mycological examinations and quantitative real-time polymerase chain reaction (PCR) targeted internal transcribed spacer (ITS) in ribosomal RNA gene at the initial visit and after 2 and 4 weeks of treatment. Assays showed that the average copy number of ITS DNA had significantly decreased to 22.9% at 2 weeks and 4.8% at 4 weeks compared with the initial visit. LLCZ topical treatment could defeat almost pathogenic dermatophytes in the scales within 4 weeks.

No abstract

Tinea unguium caused by dermatophyte species are usually treated with oral antimycotic, terbinafine (TBF). To understand the mechanisms of improvement and recalcitrance of tinea unguium by oral TBF treatment, a method of quantifying dermatophyte viability in the nail was developed, and the viability of dermatophytes was analyzed in toenail lesions of 14 patients with KOH-positive tinea unguium treated with oral TBF 125 mg/day for up to 16 weeks. Mycological tests, including KOH examination and fungal culture, and targeted quantitative real-time PCR for internal transcribed spacer (ITS) region, including rRNA, were demonstrated at the initial visit and after 8 and 16 weeks of treatment. Assays in eight patients showed that average ITS DNA amount significantly decreased, to 44% at 8 weeks and 36% at 16 weeks compared with 100% at initial visit. No significant difference was observed between at 8 and 16 weeks, despite the TBF concentration in the nail supposedly more than 10-fold higher than the minimum fungicidal concentration for dermatophytes. This finding suggests the pathogenic dermatophytes in nail lesions could survive in a dormant form, such as arthroconidia, during oral TBF treatment. Both antimycotic activity and nail growth are important factors in treatment of tinea unguium.

Phylogenetic relationships among 34 isolates from 11 Trichophyton and 3 Arthroderma species were investigated using the nucleotide sequences from 4 DNA regions: internal transcribed spacers(ITS)1 and 2 including the 5.8S rRNA gene, and the actin(ACT) , DNA topoisomerase(TOP)2 and glyceraldehyde-3-phosphate dehydrogenase(GPD)genes. All four phylogenetic trees showed that the 34 isolates can be divided into 3 clades, the Arthroderma simii, A. benhamiae and Trichophyton rubrum clades. The Shimodaira-Hasegawa test(SH test)revealed significant topological incongruities within the A. benhamiae and A. simii clades. Although branching patterns of the 3 clades were inconsistent among the four trees, the SH test did not support these differences except that the best tree topology according to ACT sequences was significantly rejected by the TOP data set. These results show that multiple gene analyses are necessary to more precisely understand the phylogenetic relationships among these fungi.