Postbiotics, defined as non-viable microbial cells, their components, or metabolites, are emerging functional ingredients that can modulate host health, including skin barrier function, immune responses, and microbial balance. The human skin microbiome plays a critical role in maintaining skin health, and the selective stimulation of beneficial commensals is of growing interest for cosmetic applications. PS-B1, a postbiotic derived from lactic acid bacteria during soy fermentation, is already used in beverages and cosmetics, but its direct effects on skin-resident bacteria have not been fully elucidated. In this study, we evaluated the effects of preservative-containing and preservative-free PS-B1 on the growth of twelve Staphylococcus strains and seven Cutibacterium acnes strains in vitro. The preservative-containing PS-B1 showed strong growth inhibition for all strains at higher concentrations. In contrast, the preservative-free PS-B1 significantly promoted the growth of Staphylococcus epidermidis, Staphylococcus hominis, and Staphylococcus lugdunensis, while Staphylococcus warneri was the only strain exhibiting growth inhibition. Other species showed no notable changes. Additionally, all C. acnes strains displayed slight growth enhancement. These results indicate that preservative-free PS-B1 selectively stimulates beneficial skin commensals, particularly S. hominis, revealing a previously unrecognized potential of PS-B1 to support a balanced skin microbiome.

Objective To elucidate the relationships among various itch qualities, blood biomarkers, and patient-reported outcome measures (PROMs) in atopic dermatitis (AD), we characterized 10 qualities of itch (QoIs) in adult Japanese patients with AD and examined their associations with blood biomarkers as well as objective and subjective clinical measures. Patients and Methods The QoI was assessed by a translated 10-item questionnaire. The relationship among each QoI and blood biomarkers (including interleukin [IL]-31, thymus and activation-regulated chemokine [TARC], and lactate dehydrogenase levels; differential white blood cell counts, including eosinophil, basophil, and neutrophil relative counts; and total immunoglobulin E levels); PROMs, such as visual analog scale and patient-oriented eczema measure; and objective measures, such as eczema area and severity index, was evaluated. Results Patients with AD frequently suffered from a sensation similar to crawling like ant (crawling) and stinging and burning sensations. Crawling was positively correlated with serum IL-31 levels but not serum TARC level. Stinging and stabbing sensations were positively correlated with serum TARC level but not with serum IL-31 levels. Stinging, stabbing, and burning sensations were correlated with PROMs and eczema area and severity index. Our limitation is that other cytokines, such as IL-4 and IL-13, were not measured. Conclusion The QoI in Japanese patients with AD could be classified into IL-31-related and TARC-related types. Our findings suggest relationships between crawling and IL-31 and between stinging and stabbing and TARC in Japanese patients with AD.

Periungual pyogenic granuloma (PG) is a benign reactive vascular lesion commonly associated with trauma and/or drug exposure, including anticancer therapies such as epidermal growth factor receptor (EGFR) inhibitors and other targeted agents. These lesions often cause pain, bleeding, and functional impairment, and may lead to interruption or dose reduction of relevant anticancer treatment. However, there remains a need for effective and noninvasive treatment options that can be easily administered in clinical practice. This study aimed to evaluate the clinical effectiveness and safety of topical timolol in patients with periungual PG. A total of 12 patients were treated with topical timolol 0.5% applied twice daily. Clinical outcomes, including lesion size, pain visual analog scale (VAS), and Dermatology Life Quality Index (DLQI), were assessed at baseline, Week 4, and Week 8. Lesion size decreased significantly over time (p = 0.003), with a significant reduction observed at Week 8 compared with baseline (p = 0.002), corresponding to a mean reduction of 60.3% at week 8. Pain VAS significantly improved at both Week 4 (p = 0.043) and Week 8 (p < 0.001), with a mean reduction of 65.5% at Week 8 compared with baseline. DLQI also improved but did not show a statistically significant change. No significant adverse events, including significant changes in blood pressure or heart rate, were observed. In conclusion, the study suggests that topical timolol is a safe and effective treatment for periungual PG, making it a valuable supportive care strategy for patients undergoing anticancer therapy.

Smooth muscle hamartoma (SMH) is a benign cutaneous tumor that typically presents at birth as a solitary lesion in the lumbosacral region. Acquired cases with multiple lesions and subtle depression are exceedingly rare. We report a 40-year-old male with a seven-year history of multiple pigmented macules with slight depression on the trunk and extremities. Histopathology of a back lesion revealed irregularly distributed bundles of pale eosinophilic smooth muscle fibers in the upper dermis, positive for α-smooth muscle actin (α-SMA). Basal hyperpigmentation was observed, without swelling of collagen fibers or atrophic eccrine glands. Differential diagnoses such as Becker's nevus and atrophoderma of Pasini and Pierini were excluded based on clinical and histological findings. Taken together, the patient was diagnosed with SMH. Although excision may be considered for solitary lesions, it was not performed in our patient due to multiple lesions. No progression was observed over two years of follow-up. This case illustrates a unique acquired SMH with multiple lesions and depressed appearance, emphasizing the importance of recognizing this entity in the differential diagnosis of multiple pigmented macules in adults.

Dupilumab, a fully human IgG4 monoclonal antibody that inhibits interleukin (IL)-4 and IL-13 signaling by blocking the shared IL-4α subunit, is the first targeted systemic therapy for moderate-to-severe atopic dermatitis (AD). The drug was introduced in Japan in April 2018, along with other countries around the same time, leading to a dramatic improvement in patients' quality of life. This study aims to provide practical insights into the real-world use of dupilumab to support decision-making in drug selection and patient education. We retrospectively analyzed the clinical course of 314 AD patients who commenced the treatment in a university hospital and two clinics in Tokyo and Yokohama, both in the greater Tokyo metropolitan area, from the launch of the drug until December 2022. Of the 314 patients, 180 (57.3%) remained on the treatment until June 2023, whereas 134 (42.7%) discontinued. Discontinuation reasons included: (i) negative outcomes, such as lack of efficacy or adverse effects, in 46 patients (14.6%) with a median treatment duration of 224 days; (ii) disease remission in 53 patients (16.9%); and (iii) non-disease-related or unknown reasons in 35 patients (11.1%). The drug survival rates at 1, 2, 3, and 4 years after initiation were 72.2%, 56.9%, 49.8%, and 42.3%, respectively. However, when considering only discontinuations due to negative outcomes, these increased to 89.3%, 82.7%, 78.8%, and 75.6%, respectively. To summarize, the drug survival rate in this group was significantly lower than those reported in Western countries. However, when discontinuations due to negative outcomes were considered separately, the rates were comparable. These findings highlight the excellent efficacy of dupilumab, while also suggesting that the doctors and patients in this region may be more inclined to discontinue the treatment despite its success compared with their Western counterparts.

OBJECTIVES:Cosmetic products, which typically contain multiple ingredients such as ethanol, glycerol and Tween 80 (polysorbate 80), may influence the homeostasis of the skin microbiome. However, the effect of common ingredients on the anaerobic members of human skin microbiome is poorly studied. In this study, we directly evaluated the effects of common cosmetic ingredients on a dominant human skin anaerobe Cutibacterium acnes using in vitro techniques. MATERIALS AND METHODS:Five cosmetic ingredients were added to seven C. acnes strains, including type strains of the three subspecies (types I, II, and III), and their effects were evaluated by monitoring growth curves based on turbidity measurements. RESULTS:All strains exhibited growth inhibition in response to high concentrations (10 % v/v) of ethanol and glycerol, whereas low concentrations (3 % and/or 1 % v/v) of ethanol enhanced bacterial growth. The nonionic detergent Tween 80 significantly enhanced the growth of type I strains, with some strains also producing insoluble precipitates, which may relate to comedogenesis. In contrast, type III strains did not produce precipitates. The two polyamines, putrescine and spermidine, elicited a biphasic response, with growth inhibition observed at higher concentrations and growth promotion at lower concentrations. CONCLUSION:The response of C. acnes subspecies/strains to the cosmetic components varied with the different ingredient concentrations, often exhibiting opposite effects.

We experienced an exceptionally rare but interesting case with adult-onset Still's disease (AOSD) accompanied by large xanthogranuloma of the eyelid, who had symptoms reminiscent of Erdheim-Chester disease (ECD). Symptoms in AOSD and ECD overlap. Therefore, we believe it is important to remind clinicians that when xanthogranuloma occurs in an AOSD patient, the possibility of ECD should be considered.

Acne vulgaris is a chronic inflammatory skin disease with a complex pathogenesis. Traditionally, the primary pathophysiologic factors in acne have been thought to be: (1) altered sebum production, (2) inflammation, (3) excess keratinization and (4) colonization with the commensal Cutibacterium acnes. However, the role of C. acnes has been unclear, since virtually all adults have C. acnes on their skin yet not all develop acne. In recent years, understanding of the role of C. acnes has expanded. It is still acknowledged to have an important place in acne pathogenesis, but evidence suggests that an imbalance of individual C. acnes phylotypes and an alteration of the skin microbiome trigger acne. In addition, it is now believed that Staphylococcus epidermidis is also an actor in acne development. Together, C. acnes and S. epidermidis maintain and regulate homeostasis of the skin microbiota. Antibiotics, which have long been a staple of acne therapy, induce cutaneous dysbiosis. This finding, together with the long-standing public health edict to spare antibiotic use when possible, highlights the need for a change in acne management strategies. One fertile direction of study for new approaches involves dermocosmetic products that can support epidermal barrier function and have a positive effect on the skin microbiome.

A Case of Multiple Acquired Depressed Smooth Muscle HamartomaShort title: Multiple Acquired Depressed Smooth Muscle HamartomaKaoru Chiba, MD1, Itaru Dekio, MD1, Isami Uno, MD1, Yoshimasa Nobeyama, MD1, Akihiko Asahina, MD11. Department of Dermatology, The Jikei University School of Medicine, Tokyo, JapanCorresponding Author: Yoshimasa NobeyamaDepartment of Dermatology, The Jikei University School of Medicine3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 105-8461, JapanTel: +81-3-3433-1111 Ext. 3341; Fax: +81-3-5401-0125E-mail nobederm@jikei.ac.jpThe authors received no financial support for this study.The authors have no conflicts of interest to declare.988 words, 2 figuresKey words : hamartoma, smooth muscle, multiple, acquired, depressed

Background: Recent descriptions of two new species of genus Cutibacterium resulted in a further expansion of the taxonomical tree of the genus, which include Cutibacterium acnes. One of the new species, Cutibacterium modestum, was coined in 2020 by the presenter as the fifth species of genus Cutibacterium, which had been tentatively named as "Propionibacterium humerusii". Another new species, Cutibacterium porci, was firstly isolated from porcine faeces by Wylensek et al. in 2020, being the first Cutibacterium species possibly the only non-human member of the genus. Following these new findings, researchers need a map of status quo of the genus. Methods: To describe the comprehensive view of the species and subspecies of the genus and to verify their taxonomical positions, we applied three of the several taxonomical tools, which are in silico DNA-DNA hybridization, the average nucleotide identity, and MALDI-TOF mass spectrometry. Results: Our genome-based approaches (in silico DNA-DNA hybridization and the average nucleotide identity) enabled the tree view of these species and subspecies, and verified the individual status of the species/subspecies by the pairwise similarity values (species cutoff: 70% in in silico DNA-DNA hybridization and 95% in the average nucleotide identity; subspecies cutoff: 79% and 99%, respectively). Furthermore, the proteomic approach (MALDI-TOF mass spectrometry) showed the effective differentiation of these species/subspecies by using 3,000-15,000 m/z range of the spectral patterns of this latest identifying tool. Discussion: Dermatological researchers are to see these new species names in coming years. Our presenting information will help them to understand the taxonomical background and get more familiarized to these names.

The data that support the findings of this study are available on request from the corresponding author.

Cutibacterium acnes (C. acnes) is known to play a central role in pathogenesis of acne vulgaris. It has been understood that multiple phylotypes of C. acnes exist, with certain types being more prevalent in patient with acne vulgaris and others more common in healthy individuals. In this context, we conducted a preliminary study using self-collected samples via an adhesive sticker (MySkin® patch) to analyze the skin microbiome of Japanese women. The study aimed to determine the role of C. acnes and its specific phylotypes in the development of acne vulgaris.Participants in this study were Japanese females aged between their 20s and 40s. Dermatologists evaluate the data from web-based questionnaires and smartphone image submissions to classify subjects into either Acne group (n = 219) or Non-acne group (n = 77). Quality assessment of DNA extracted from the sticker was conducted, followed by amplification of the 16S rRNA region using PCR. Subsequent microbial community analysis was performed using next-generation sequencing techniques. Genetic classification of C. acnes was accomplished through single locus sequence typing.Results indicated a bacterial community composition on the facial skin surface predominantly consisting of C. acnes clusters, with over half of these clusters constituted by C. acnes . Notably, the Acne group exhibited a significantly higher proportion of C. acnes relative to total bacterial presence compared to the Non-acne group. Analysis of C. acnes phylotypes revealed a markedly lower presence of type III (subspecies elongatum ) in the Acne group (vs. Non-acne group, p < 0.05). No significant differences were observed in the prevalence of Types IA1, IA2, II, and IB between the two groups. The predominantsequence types (ST) of C. acnes identified were IA2\_2\_F0 (23.9%), IA1\_4\_A0 (20.6%), and II\_2\_K0 (18.6%). Within the Acne group, an increase in IA2\_1\_F1 and a decrease in III\_1\_L0 were observed (vs. Non-acne group, p < 0.05).This study underscores the feasibility of using self-collected and mailed-in samples for qPCR and microbiome analysis, maintaining diagnostic quality comparable to in-person assessments. Furthermore, the variation in the expression of C. acnes phylotypes across skin surfaces between acne-afflicted and healthy individuals could suggest that shifts in phylotype expression patterns may be indicative of skin susceptibilities to acne development.### Competing Interest StatementThe authors have declared no competing interest.

In 2016, a new species name Cutibacterium acnes was coined for the well-documented species, Propionibacterium acnes, one of the most successful and clinically important skin commensals. The nomenclatural changes were brought about through creation of the genus Cutibacterium, when a group of propionibacteria isolates from the skin were transferred from the genus Propionibacterium and placed in the phylum Actinobacteria.Almost simultaneously, the discovery of two novel species of Cutibacterium occurred and the proposal of three subspecies of C. acnes were reported. These dramatic changes that occurred in a long-established taxon made it challenging for the non-specialist to correlate the huge volume of hitherto published work with current findings. In this review, we aim to correlate the eco-specificity and pathophysiological properties of these newly circumscribed taxa. We envisage that this information will shed light on the pathogenic potential of new isolates and enable better assessment of their clinical importance in the foreseeable future.Currently, five species are recognized within the genus: Cutibacterium acnes, Cutibacterium avidum, Cutibacterium granulosum, Cutibacterium modestum (previously, “Propionibacterium humerusii”), and Cutibacterium namnetense. These reside in different niches reflecting their uniqueness in their genetic makeup. Their pathogenicity includes acne inflammation, sarcoidosis, progressive macular hypomelanosis, prostate cancer, and infections (bone, lumbar disc, and heart). This is also the case for the three newly described subspecies of C. acnes, which are C. acnes subspecies acnes (C. acnes type I), subspecies defendens (C. acnes type II), and subspecies elongatum (C. acnes type III). C. acnes subspecies acnes is related to inflamed acne and sarcoidosis, while subspecies defendens to prostate cancer and subspecies elongatum to progressive macular hypomelanosis. Because the current nomenclature is based upon polyphasic analyses of the biochemical and pathogenic characteristics and comparative genomics, it provides a sound basis studying the pathophysiological roles of these species.

Cutibacterium modestum is a new species coined in 2020 as the fifth species of genus Cutibacterium, which includes Cutibacterium acnes. The species is predicted as a minor but common member of skin microbiome and includes a group tentatively named as “Propionibacterium humerusii”. The description of the species has been provided only with a single strain. To establish the characteristics of C. modestum and search for possible disease-related subtypes, we investigated the biochemical characteristics of eight live strains and performed in silico comparison of nine genomes. The common features, which included the morphology of Gram-stain positive short rods, the negativity of phenylalanine arylamidase, and several unique MALDI-TOF MS spectral peaks, were considered useful in laboratory identification. Pairwise comparisons of the genomes by in silico DNA–DNA hybridization showed similarity values of 98.1% or larger, which were far higher than the subspecies cutoff of 79–80%. The 16S rRNA gene sequences of thirteen isolates and genomes were identical. Their recA gene sequences were identical except for two strains, HM-510 (HL037PA2) and Marseille-P5998, which showed unique one-nucleotide polymorphisms. The biochemical features using API kits were slightly different among the isolates but far closer than those of the nearest other species, C. acnes and Cutibacterium namnetense. Spectra of MALDI-TOF mass spectrometry showed slight differences in the presence of m/z 10,512 (10 kD chaperonin GroS) and three other peaks, further clustering the eight isolates into three subtypes. These results indicated that these isolates did not separate to form subspecies-level clusters, but subtyping is possible by using recA gene sequences or MALDI-TOF mass spectrometry spectra. Moreover, this work has confirmed that a group “P. humerusii” is included in C. modestum.

Matrix-assisted laser-desorption/ionization time-of-flight (MALDI–TOF) mass spectrometry is a widely used and reliable technology to identify microbial species and subspecies. The current methodology is based on spectral fingerprinting, analyzing protein peaks, most of which are yet to be characterized. In order to deepen the understanding of these peaks and to develop a more reasonable identification workflow, we applied proteogenomic approaches to assign the high-intensity peaks of MALDI–TOF spectra of two bacterial genera. First, the 3–22 kD proteomes of 5 Cutibacterium strains were profiled by UPLC–MS/MS, and the amino acid sequences were refined by referring to their genome in the public database. Then, the sequences were converted to m/z (x-axis) values based on their molecular masses. When the interspecies comparison of calculated m/z values was well-fitted to the observed peaks, the peak assignments for the five Cutibacterium species were confirmed. Second, the peak assignments for six Staphylococcus species were performed by using the above result for Cutibacterium and referring to ribosomal subunit proteins coded on the S10-spc-alpha operon (the S10-GERMS method), a previous proteomics report by Becher et al., and comprehensive genome analysis. We successfully assigned 13 out of 15 peaks for the Cutibacterium species and 11 out of 13 peaks for the Staphylococcus species. DNA-binding protein HU, the CsbD-like protein, and 50S ribosomal protein L7/L12 were observed in common. The commonality suggests they consist of high-intensity peaks in the MALDI spectra of other bacterial species. Our workflow may lead to the development of a more accurate species identification database of MALDI–TOF mass spectrometry based on genome data.

This book chapter presents an overview and discussion of the use of MALDI-TOF MS for fungal identification. The major known limitations of the technique for fungal taxonomy, and how to overcome these, are also discussed. Moreover, this should guarantee that spectra deposited in such MALDI-TOF MS database would remain public, preferably in open free access. To avoid misidentification, these stored spectra must be curated and based on well-established standard operating procedures. The number of spectra available within species needs to be increased to accommodate the diversity and geographic differences, unique strain traits and the varied culture conditions and procedures in order to establish a single public and open access MALDITOF MS database. This could then be used with metadata analysis and artificial intelligence algorithms, to provide reliable fungal identification.

An anaerobic and aerotolerant bacterium, strain M12T, was isolated from the meibum of inflamed human meibomian glands. Cells of the strain was Gram-stain-positive, non-spore-forming and non-motile rods. Growth on trypticase soy agar plates supplemented with 5 % sheep blood was fastest at 30-37 °C under anaerobic conditions. The 16S rRNA gene sequence of the strain revealed that it belongs to the genus Cutibacterium with a 98.0 % similarity value to the closest species, Cutibacterium acnes. Genome analysis of the strain with type strains of the other Cutibacterium species resulted in digital DNA-DNA hybridization values of 32.3-22.3% and average nucleotide identity (OrthoANI) values of 86.7-73.6 %. Biochemical and physiological analyses using API rapid ID 32A and API Coryne kits revealed relatively low reactivity of the strain compared with C. acnes and Cutibacterium namnetense. The most abundant major cellular fatty acid was iso-C15 : 0. Fermentation end-products from glucose were propionate, lactate, succinate and acetate. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. Major menaquinones were MK-9(H4), MK-9(H2) and MK-9. The major peaks of the MALDI-TOF mass spectrometry spectrum were at 3493, 3712, 6986 and 7424 Da. The DNA G+C content was 59.9 mol%. Based on these findings, we propose a novel species, Cutibacterium modestum. The type strain of C. modestum is M12T (=JCM 33380T=DSM 109769T). On the basis of further genomic analysis, we also provide emended descriptions of Cutibacterium granulosum (Prévot 1938) Scholz and Kilian 2016 and Cutibacterium namnetense (Aubin et al. 2016) Nouioui et al. 2018.