Homeostatic Control of Sebaceous Glands by Innate Lymphoid Cells Regulates Commensal Bacteria Equilibrium.

Immune cells and epithelium form sophisticated barrier systems in symbiotic relationships with microbiota. Evidence suggests that immune cells can sense microbes through intact barriers, but regulation of microbial commensalism remain largely unexplored. Here, we uncovered spatial compartmentalization of skin-resident innate lymphoid cells (ILCs) and modulation of sebaceous glands by a subset of RORγt+ ILCs residing within hair follicles in close proximity to sebaceous glands. Their persistence in skin required IL-7 and thymic stromal lymphopoietin, and localization was dependent on the chemokine receptor CCR6. ILC subsets expressed TNF receptor ligands, which limited sebocyte growth by repressing Notch signaling pathway. Consequently, loss of ILCs resulted in sebaceous hyperplasia with increased production of antimicrobial lipids and restricted commensalism of Gram-positive bacterial communities. Thus, epithelia-derived signals maintain skin-resident ILCs that regulate microbial commensalism through sebaceous gland-mediated tuning of the barrier surface, highlighting an immune-epithelia circuitry that facilitates host-microbe symbiosis.

High bacterial colonization and lipase activity in microcomedones.

BACKGROUND: Although acne vulgaris has a multifactorial aetiology, comedogenesis and bacteria colonization of the pilosebaceous unit are known to play a major role in the onset of inflammatory acne lesions. However, many aspects remain poorly understood such as where and when is the early stage of the Propionibacterium acnes colonization in follicular unit? Our research aimed at providing a precise analysis of microcomedone's structure to better understand the interplay between Propionibacterium acnes and follicular units, and therefore, the role of its interplay in the formation of acne lesions. METHODS: Microcomedones were sampled using cyanoacrylate skin surface stripping (CSSS). Their morphology was investigated with multiphoton imaging and their ultrastructure with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Bacterial lipase activity in the microcomedones was quantified using a dedicated enzymatic test as well as a Fourier Transform Infra-Red (FTIR) analysis. The porphyrin produced by bacteria was analysed with HPTLC and fluorescence spectroscopy. RESULTS: The imaging analysis showed that microcomedones' structure resembles a pouch, whose interior is mostly composed of lipids with clusters of bacteria and whose outer shell is made up of corneocyte layers. The extensive bacteria colonization is clearly visible using TEM. Even after sampling, clear lipase activity was still seen in the microcomedone. A high correlation, r = .85, was observed between porphyrin content measured with HPTLC and with fluorescence spectroscopy. These observations show that microcomedones, which are generally barely visible clinically, already contain a bacterial colonization.

Investigation on Microecology of Hair Root Fungi in Androgenetic Alopecia Patients.

BACKGROUND: This study focused on the differences in hairy root fungal microecology between androgenetic alopecia patients and healthy individuals. METHODS: Light microscopy was used to observe the morphology of hairy roots. Morphological observations were also performed in the positive specimens using scanning electron microscopy and transmission electron microscopy. The high-throughput sequencing method was used to detect the fungal microecology of hairy roots at different sites. Moreover, the comparison of fungal loads of Malassezia in different group and scalp area were tested by PCR. RESULTS: The fungi in the hair root observed by optical microscopy are mainly Malassezia yeast. The positive rate of Malassezia in the hair loss group (60%) was higher than that in the control group (40%). The detection efficiency of Malassezia examined by scanning electron microscopy was higher than that by light microscopy. Results acquired from high-throughput molecular sequencing of fungi suggested that Ascomycota was the dominant species, whereas in the occipital hair roots of the control group Basidiomycota was the dominant species in the hair loss group. Malassezia followed by Trichosporon were the most abundant fungal genera. The changes in abundance at the top and occipital region of the control group were more significant than those of the genus Fusarium, followed by Epicoccum and Malassezia. The load of Malassezia located on calvaria in the alopecia group was significantly higher than that in the control group. In the alopecia group, the load of Malassezia on the scalp was higher than that on the occipital region. The load of Malassezia globosa and Malassezia restricta in the hair loss group was higher on calvaria and occipital areas. CONCLUSION: Malassezia had a positive correlation with the incidence of androgenic alopecia.

[Tinea barbae profunda due to Trichophyton mentagrophytes : Case report and review]. / Tinea barbae profunda durch Trichophyton mentagrophytes : Patientenbeschreibung und Übersicht.

Tinea barbae is a rare dermatomycocis, by definition follicular bound in the beard area of adult men. Manifestation usually starts with erythema accompanied by desquamation. Deeper distribution along terminal hairs leads to folliculitis with formation of pustules and nodes as well as abscesses; fixed adherent yellowish crusts may appear. Frequently there is locoregional swelling of the lymph nodes and occasionally a deterioration of general condition with (sub)febrile temperatures. Often this leads to the initial suspected diagnosis of a bacterial folliculitis barbae or impetigo contagiosa. Tinea barbae is mostly induced by species of the genus Trichophyton (T.). The pathogens are diverse and are mostly zoophilic, sometimes anthropophilic and rarely geophilic dermatophytes. With the help of a specific anamnesis and diagnostic procedure, including mycological examinations, histology and molecular detection of dermatophytes via polymerase chain reaction (PCR), tinea barbae-in our patient induced by T. mentagrophytes-can be rapidly diagnosed. Early initiation and adequate treatment duration lead to restitutio ad integrum.

Tinea folliculorum complicating tinea of the glabrous skin: an important yet neglected entity.

Dermatophytes are capable of infecting the skin and its appendages such as nails and hairs producing a variety of clinical conditions. Hair invasion by dermatophytes is a key feature of tinea capitis and tinea barbae but not of tinea of glabrous skin. In this project, we studied the clinico-mycological aspects of follicular involvement in patients with dermatophytosis of the glabrous skin. In total, 16 patients, eight males and eight females, were included in the study. All were adults except for one girl. The disease durations ranged from one month to more than ten years. Fourteen (78.5%) had multiple lesions, and most of them had undergone treatment with antifungals, antibiotics, or steroids. Dermoscopic examination showed infected hairs in the form of broken stubs, coily, curly, or as black dots on the surface of the lesions. Pathogens were either anthropophilic (seven cases of Trichophyton rubrum) or zoophilic (six cases Microsporum canis, three cases of the T. mentagrophytes). Patients responded well to oral griseofulvin or terbinafine, and topical antifungals. No antifungal resistance developed during the treatment course. Follicular involvement of glabrous skin is not as rare as previously thought and should be considered for systemic antifungal treatments.

Is Human Sebum the Source of Skin Follicular Ultraviolet-Induced Red Fluorescence? A Cellular to Histological Study.

BACKGROUND: The ultraviolet-induced red fluorescence (UVRF) from human skin follicles was suggested to be a result of Propionibacterium acnes and was used for the monitoring of acne. More recent studies suggested that the UVRF may be more related to sebum rather than to microorganisms. OBJECTIVE: To clarify whether human sebum or follicular microorganisms are the source of UVRF. METHODS: We examined the fluorescence of human-derived SZ95 sebocytes, human sebaceous glands, sebum extracted from the sebaceous glands, and bacteria isolated from human hair follicles under ultraviolet light. RESULTS: SZ95 sebocytes, human sebaceous glands, and sebum do not emit UVRF. Two types of UVRF peaking at about 635 nm and at about 620 nm were detected in P. acnes and Staphylococcus epidermidis, respectively. This is the first report that S. epidermidis emits UVRF when it is anaerobically cultured and then exposed to air. CONCLUSION: Human follicular UVRF is emitted by resident bacteria, not by sebum. Therefore, UVRF may be used to monitor certain species of skin microorganisms.

Deep facial mycosis due to Trichophyton verrucosum-molecular genetic identification of the dermatophyte in paraffin-embedded tissue-case report and review of the literature.

Deep trichophytosis is relatively uncommon. The infection of the bearded area is also known as sycosis barbae or tinea barbae and can be caused by various fungal species, most often zoophilic fungi. We report on an 80-year-old male patient with severe sycosis barbae who had no animal contact and was treated with systemic antibiosis without improvement. Microbial and mycological investigations using swabs from oozing lesions revealed Staphylococcus haemolyticus and Candida parapsilosis. Histology demonstrated fungal elements in hair follicles. Paraffin-embedded material was subjected to further mycological analysis. For molecular diagnostics DNA was prepared from paraffin sections for real-time polymerase chain reaction (RT-PCR). For sequencing, DNA was isolated from paraffin-embedded skin tissue and the ITS region of the rDNA was selected. Sequencing of the ITS2 region of rRNA revealed a 100% accordance with Trichophyton (T.) verrucosum. Treatment with oral terbinafine achieved a complete remission. Sycosis barbae is an important differential diagnosis for infections of the bearded area. Nucleic acid amplification techniques (NAAT) are more and more used for direct examination of dermatophytes in clinical samples, eg T. verrucosum. NAAT are also used as culture confirmation tests for identification of rare dermatophytes like T. verrucosum. Today, singleplex and multiplex quantitative real-time PCR (qRT-PCR) assays for the detection of the most common dermatophytes including T. verrucosum in clinical specimens are available. Recently, an ITS2 PCR assay has been successfully used for direct detection of T. verrucosum in paraffin-embedded formalin-fixed skin tissue. The PCR is fast and highly specific. The sensitivity of direct molecular detection of the dermatophytes both in native clinical material, and in paraffin-embedded skin tissue can been increased.

Microbial colonization of normal skin: Direct visualization of 194 skin biopsies.

Recent genetic studies have suggested the presence of numerous microbial species on and in the skin. We characterised microbial colonization of a large collection of skin biopsies from 194 healthy subjects by fluorescence assay. Forty per cent of all biopsies did not show any evidence for microbial colonization. Propionibacterium acnes was the sole predominant bacterial species in both sebaceous and non-sebaceous areas. Non- P. acnes species were present in approximately 30% of all colonized samples. . Only hair follicles and stratum corneum were colonized. Understanding of cutaneous microbiota requires validation from a variety of approaches and techniques.

[A recurrent case of adult favus successfully treated with terbinafine]. / Terbinafi n ile basarili olarak tedavi edilen bir eriskin nüks favus olgusu.

Favus or tinea capitis favosa, is a chronic inflammatory dermatophytosis of the scalp. The disease is particularly common in children aged 6 to 10 years, more often in boys, and it also occurs in adults. Human-to-human transmission is therefore possible. Anthropophilic Trichophyton schöenleinii is responsible for over 95% of favus cases. In addition, there are rare cases of anthropophilic T.violaceum, zoophilic (T.verrucosum, T.quinckeanum, and Microsporum canis) and geophilic M.gypseum species recorded as agents of favus. It is also reported in mice (T.quinckeanum), poultry (M.gallinae), and cats (M.incurvatum). Favus is common in Iran, Nigeria, and China, however it has been reported rarely in the last two decades in Turkey. Although Turkish records are not sufficient to indicate an accurate incidence rate, favus is still present in Turkey. In this report, a 20-year-old female with favus was presented. She had squames and areas of alopecia on the right frontoparietal area of her scalp. Scalp biopsy and hair follicle samples were taken for histopathological examination and fungal culture. According to the conventional identification by mycological methods and internal transcribed spacer (ITS) sequencing analysis, the pathogen was identified as T.schöenleinii. The patient was treated with oral terbinafine (250 mg/day) for 4 weeks and topical isoconazole and ketoconazole for 6 weeks. Clinical recovery was observed after 6 weeks, however, fungal culture could not be repeated. Six months after the initial presentation, the patient's symptoms recurred due to the poor adherence and T.schöenleinii was repeatedly grown in culture. Antifungal treatment was administered with the same drugs for the same period. There was a clinical and mycological recovery 8 months after initial presentation. Favus, which is not frequently observed in adults, is an uncommon disease. Confusion arises in its diagnosis because other diseases have similar clinical appearances, and asymptomatic carriage have also been reported. For these reasons, and because of improvements in health conditions, treatment might be delayed. With accurate assessment of the patient's medical history, the clinical characteristics of the disease, and results of laboratory analyses, coupled with effective mycologist-clinician collaboration, it is possible for the patient to continue a healthy social life. Consequently, favus is still an important health problem encountered in Turkey.

Three dimensional distribution of Propionibacterium acnes biofilms in human skin.

Propionibacterium acnes is regarded as a common member of the human skin microbiota, often occurring in biofilms. Little is known about the size of bacterial biofilms in hair follicles as a few sections of biopsy tissue are routinely evaluated. Transversal sectioning provides a better opportunity for histological analyses of hair follicles which can be followed through the different morphological levels. Direct visualization of P. acnes biofilms in hundreds of consecutive sections allowed insight into the 3D distribution in human hair follicles as well as investigating the depth of biofilm distribution within hair follicles. Four distinct colonization patterns of P. acnes biofilms were revealed. Results have shown that an individual P. acnes biofilm can spread for 1900 µm in a terminal hair follicle. This information can be of help while designing potential antibiofilm treatment.

Heat-treated Limosilactobacillus fermentum LM1020 with menthol, salicylic acid, and panthenol promotes hair growth and regulates hair scalp microbiome balance in androgenetic alopecia: A double-blind, randomized and placebo-controlled clinical trial.

BACKGROUND: Androgenetic alopecia (AGA) is a common and chronic problem characterized by hair follicle miniaturization. AIMS: In this study, heat-treated Limosilactobacillus fermentum LM1020 (HT-LM1020) was investigated in human follicle dermal papilla cell (HFDPC), scalp tissue, and clinical trials for patients with AGA. PATIENTS/METHODS: Cell proliferation and the expression of cyclins and cyclin-dependent kinases (CDKs) were measured in HFDPC. The relative gene expression of 5α-reductase and growth factors were investigated in hair scalp. This double-blind, randomized, placebo-controlled clinical trial was conducted over 24 weeks. Primary efficacy was evaluated by measuring hair density, and secondary efficacy was assessed by experts and self-assessment. Changes in the microbiota of the hair scalps were analyzed using 16S metagenome amplicon sequencing. RESULTS: HT-LM1020 promoted cell growth (p < 0.001) and cyclin B1 expression, and it reduced 5α-reductase and induced fibroblast growth factor 7 (FGF7), FGF10, and epithelial growth factor7 (EGF7) (p < 0.001). In the clinical trial, the experimental group demonstrated an increase in hair density from 133.70 to 148.87 n/cm2 at Week 24 (p < 0.001), while also expressing satisfaction with their hair density, reduced hair loss, and hairline. At Week 24, the total ratio of lactic acid bacteria operational taxonomic unit (OTU) in the scalp increased from 6.65% to 26.19%. At the same period, placebo-controlled group decreased Staphylococcus caprae OTU from 77.95% to 14.57% while experimental group decreased from 65.80% to 41.02%. CONCLUSIONS: These present results showed that HT-LM1020 was a co-effector of ingredients for anti-hair loss contributing to cell proliferation and the expression of CDKs.

Antibacterial toner exhibits bactericidal effect against Cutibacterium acnes via keratin and sebum plug penetration.

Cutibacterium acnes is an opportunistic pathogen recognized as a contributing factor to acne vulgaris. The accumulation of keratin and sebum plugs in hair follicles facilitates C. acnes proliferation, leading to inflammatory acne. Although numerous antimicrobial cosmetic products for acne-prone skin are available, their efficacy is commonly evaluated against planktonic cells of C. acnes. Limited research has assessed the antimicrobial effects on microorganisms within keratin and sebum plugs. This study investigates whether an antibacterial toner can penetrate keratin and sebum plugs, exhibiting bactericidal effects against C. acnes. Scanning electron microscopy and next-generation sequencing analysis of the keratin and sebum plug suggest that C. acnes proliferate within the plug, predominantly in a biofilm-like morphology. To clarify the potential bactericidal effect of the antibacterial toner against C. acnes inside keratin and sebum plugs, we immersed the plugs in the toner, stained them with LIVE/DEAD BacLight Bacterial Viability Kit to visualize microorganism viability, and observed them using confocal laser scanning microscopy. Results indicate that most microorganisms in the plugs were killed by the antibacterial toner. To quantitatively evaluate the bactericidal efficacy of the toner against C. acnes within keratin and sebum, we immersed an artificial plug with inoculated C. acnes type strain and an isolate collected from acne-prone skin into the toner and obtained viable cell counts. The number of the type strain and the isolate inside the artificial plug decreased by over 2.2 log and 1.2 log, respectively, showing that the antibacterial toner exhibits bactericidal effects against C. acnes via keratin and sebum plug penetration.

A Novel 3D Printed Model of Infected Human Hair Follicles to Demonstrate Targeted Delivery of Nanoantibiotics.

Hair follicle-penetrating nanoparticles offer a promising avenue for targeted antibiotic delivery, especially in challenging infections like acne inversa or folliculitis decalvans. However, demonstrating their efficacy with existing preclinical models remains difficult. This study presents an innovative approach using a 3D in vitro organ culture system with human hair follicles to investigate the hypothesis that antibiotic nanocarriers may reach bacteria within the follicular cleft more effectively than free drugs. Living human hair follicles were transplanted into a collagen matrix within a 3D printed polymer scaffold to replicate the follicle's microenvironment. Hair growth kinetics over 7 days resembled those of simple floating cultures. In the 3D model, fluorescent nanoparticles exhibited some penetration into the follicle, not observed in floating cultures. Staphylococcus aureus bacteria displayed similar distribution profiles postinfection of follicles. While rifampicin-loaded lipid nanocapsules were as effective as free rifampicin in floating cultures, only nanoencapsulated rifampicin achieved the same reduction of CFU/mL in the 3D model. This underscores the hair follicle microenvironment's critical role in limiting conventional antibiotic treatment efficacy. By mimicking this microenvironment, the 3D model demonstrates the advantage of topically administered nanocarriers for targeted antibiotic therapy against follicular infections.

Hair loss in pityriasis versicolor lesions: a descriptive clinicopathological study.

BACKGROUND: We have observed that hair thinning and/or loss occur at times as a presenting symptom or sign in patients with pityriasis versicolor (PV). OBJECTIVE: Our objective was to verify and explore this clinical observation and depict its underlying pathology. METHODS: A total of 39 patients with PV were examined during a period of 11 months and skin biopsy specimens were taken from lesional and nonlesional skin. Hematoxylin-eosin- and periodic acid-Schiff-stained sections were examined and described. Results were statistically analyzed. RESULTS: Hair loss and/or thinning within PV lesions was shown in 61.5% of patients (P value < .0005), appearing most commonly on forearms, abdomen, and neck as well as the beard area (only in male participants). Histopathologically, in addition to the classically described features of PV, basal hydropic degeneration, follicular degeneration, miniaturization, atrophy, plugging, and/or hair shaft absence occurred in 46% of lesional versus 20.5% of nonlesional biopsy specimens (P value < .05); these changes appeared to be directly or indirectly related to the presence of Malassezia organisms in hair follicles and/or stratum corneum. LIMITATIONS: Some patients with PV lesions on the face did not approve facial biopsy. CONCLUSION: This study provides clinical and histopathological evidence that PV lesions may be associated with hair thinning and/or loss.

Pitfall scarring alopecia: favus closely mimicking lichen planus.

We describe a woman presenting primarily with slowly progressing scarring alopecia. Course, symptoms, and clinical picture were highly suggestive for lichen planus. But mycological investigations revealed that cicatricial alopecia was caused by a specific infection with Trichophyton schoenleinii running a chronic course with minimal skin inflammation.

First evidence of bacterial biofilms in the anaerobe part of scalp hair follicles: a pilot comparative study in folliculitis decalvans.

BACKGROUND: The cause of folliculitis decalvans (FD) remains unknown. We hypothesized that a bacterial biofilm could be involved in its pathogenesis. OBJECTIVE: To assess the presence or not of a bacterial biofilm in the hair roots of the scalp in FD. PATIENTS AND METHODS: Hairs plucked from four patients and three controls were examined by field emission scanning electron microscopy (FESEM) and confocal laser scanning microscopy (CLSM). RESULTS: Bacterial communities organized as biofilms were observed both by FESEM and CLSM in the under infundibular part of hair follicles in all patients and in two of the three controls. In patients and controls, these biofilms were formed exclusively of bacilli of comparable shapes. CONCLUSION: This pilot study provides the first evidence of the presence of bacterial biofilms in the infra infundibular part of human scalp hair follicles. These biofilms were detected both in FD patients and controls, suggesting their ubiquity as a commensal biofilm with a possible pathogenic shift in FD.

Simultaneous visualization of Propionibacterium acnes and Propionibacterium granulosum with immunofluorescence and fluorescence in situ hybridization.

Propionibacterium acnes (P. acnes) and Propionibacterium granulosum (P. granulosum) are common skin colonizers that are implicated as possible contributing factors in acne vulgaris development. We have established direct visualization tools for the simultaneous detection of these closely related species with immunofluorescence assay and fluorescence in situ hybridization (FISH). As proof of principle, we were able to distinguish P. acnes and P. granulosum bacteria in multi-species populations in vitro as well as in a mock skin infection model upon labelling with 16S rRNA probes in combinatorial FISH as well as with antibodies. Furthermore, we report the co-localization of P. acnes and P. granulosum in the stratum corneum and hair follicles from patients with acne vulgaris as well as in healthy individuals. Further studies on the spatial distribution of these bacteria in skin structures in various skin disorders are needed.

Hidradenitis suppurativa: A practical review of possible medical treatments based on over 350 hidradenitis patients.

Hidradenitis suppurativa (HS), a pathological follicular disease, impacts patients' lives profoundly. HS most commonly involves cutaneous intertriginous areas, such as the axilla, inner thighs, groin and buttocks, and pendulous breasts, but can appear on any follicular skin. Protean, HS manifests with variations of abscesses, folliculitis, pyogenic granulomas, scars (oval honeycombed), comedones, tracts, fistulas, and keloids. The pathophysiology might involve both defects of the innate follicular immunity and overreaction to coagulase negative Staphylococcus. Treatment depends on the morphology, extent, severity, and duration. Topical clindamycin and dapsone are often adequate for treating mild HS. For Stage 1 and 2 HS, first line treatment combines rifampin with either oral clindamycin or minocycline. Other HS treatments include: fluoroquinolones with metronidazole and rifampin, oral dapsone, zinc, acitretin, hormone blockers (oral contraceptive pills, spironolactone, finasteride, and dutasteride), and oral prednisone. For severe HS, cyclosporine, adalimumab, or infliximab (used at double psoriatic doses) and intravenous carbapenems or cephalosporins are often required. Isotretinoin, etanercept, isoniazid, lymecycline, sulfasalazine, methotrexate, metformin, colchicine, clarithromycin, IVIG, and thalidomide are less favored treatments. The role of botulinum toxin is uncertain. The most important life style modification is weight loss. De-roofing fluctuant nodules and injection of intralesional corticosteroids ameliorates the disease and perhaps, if done at regular intervals, improves HS more permanently. Surgical excision and CO2 laser ablation are more definitive treatments. The 1064 nm laser for hair removal aids in the treatment of HS. This article centers on medical therapies and will only passingly mention surgical and laser treatments. This article summarizes my treatment experience with over 350 HS patients.