Search

Skin is innervated by a multitude of sensory nerves that are important to the function of this barrier tissue in homeostasis and injury. The role of innervation and neuromediators has been previously reviewed so here we focus on the role of the transient receptor potential cation channel, subfamily V member 1 (TRPV1) in wound healing, with the intent of targeting it in treatment of non-healing wounds. TRPV1 structure and function as well as the outcomes of TRPV1-targeted therapies utilized in several diseases and tissues are summarized. In skin, keratinocytes, sebocytes, nociceptors, and several immune cells express TRPV1, making it an attractive focus area for treating wounds. Many intrinsic and extrinsic factors confound the function and targeting of TRPV1 and may lead to adverse or off-target effects. Therefore, a better understanding of what is known about the role of TRPV1 in skin and wound healing will inform future therapies to treat impaired and chronic wounds to improve healing.

Sadan Mohammed Al Harbi, Nasser Mohammed Al Saif, Ahmad Mawkili, Sarah Al Breiki Department of Dermatology, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Eastern Province, Saudi ArabiaCorrespondence: Sadan Mohammed Al Harbi, Department of Dermatology, College of Medicine, Imam Abdulrahman Bin Faisal University, Post Box No. 1982, Dammam, 31441, Saudi Arabia, Email Smharbi@iau.edu.saAbstract: Demodex folliculorum is a common ectoparasite of humans that inhabits follicular infundibulum and sebaceous ducts. Its role in various dermatological diseases is well studied. However, data on demodex-induced skin pigmentation are very limited. A diagnosis of this entity can be easily missed for other causes of facial hyperpigmentation such as melasma, lichen planus pigmentosus, erythema dyschromicum perstans, post-inflammatory hyperpigmentation, and drug-induced hyperpigmentation. Here, we report a case of facial demodicosis-induced skin hyperpigmentation in a 35-year-old Saudi male who is on multiple immunosuppressive agents. He was successfully treated with ivermectin 1% cream and had a dramatic improvement at his 3-month follow-up. Our aim is to shed light on this underdiagnosed cause of facial hyperpigmentation which can be easily diagnosed and followed up by bed side dermoscopic examination and managed effectively by anti-demodectic therapies.Keywords: demodex, hypermelanosis, ivermectin, pilosebaceous unit

Demodex folliculorum is a common ectoparasite of humans that inhabits follicular infundibulum and sebaceous ducts. Its role in various dermatological diseases is well studied. However, data on demodex-induced skin pigmentation are very limited. A diagnosis of this entity can be easily missed for other causes of facial hyperpigmentation such as melasma, lichen planus pigmentosus, erythema dyschromicum perstans, post-inflammatory hyperpigmentation, and drug-induced hyperpigmentation. Here, we report a case of facial demodicosis-induced skin hyperpigmentation in a 35-year-old Saudi male who is on multiple immunosuppressive agents. He was successfully treated with ivermectin 1% cream and had a dramatic improvement at his 3-month follow-up. Our aim is to shed light on this underdiagnosed cause of facial hyperpigmentation which can be easily diagnosed and followed up by bed side dermoscopic examination and managed effectively by anti-demodectic therapies. [ABSTRACT FROM AUTHOR]

Background: Acne vulgaris (AV) is a typical inflammation-related condition of the pilosebaceous apparatus that has extremely detrimental impact on one's quality of life & mental health. Interleukin (IL)-36 cytokines (α, β, γ) promote the activation of T-helper 1 and T-helper-17 cells, which then secrete tumor necrosis factor-, interferon-γ, IL-17, IL-22 in addition to other inflammatory mediators. These cytokines stimulate epithelial cells for producing numerous growth factors and inflammatory mediators, thereby exacerbating the inflammation. IL-36 cytokines have been associated with various conditions that are inflammation-related. Aim: Its objective was to evaluate IL-36γ serum levels among AV participants and healthy controls, and to look into any possible connection among IL-36 & the severity of AV. Patients and methods: 45 participants were enrolled in this study after they presented with AV, along with 45 controls who did not have AV. Enzyme-linked immunosorbent assay (ELISA) was utilized to evaluate serum levels of IL-36γ in AV patients and controls. Results: The study revealed that cases with AV had significantly higher IL-36γ serum levels than controls (p < 0.001). IL-36γ serum levels correlated positively with AV severity (P=0.002). Cases with severe acne had higher levels than those with mild & moderate acne (p=0.005). Moreover, IL-36γ serum levels were significantly higher among cases with positive family history of AV (p=0.019). Conclusion: Individuals with AV had significantly greater serum IL-36γ levels in contrast to controls and they were related to AV severity and post acne scarring. IL-36γ may therefore show a significant function in AV inflammatory reactions and the induction of post acne scarring. [ABSTRACT FROM AUTHOR]

Introduction: Adnexal skin tumours are a heterogeneous group of uncommon tumours usually misdiagnosed clinically due to a huge variety of types and their variants. Histopathology usually helps in establishing the diagnosis. The study was conducted to analyse the morphological, clinical and histological features of adnexal tumours (ATs) of the skin at our centre over a period of 5 years. Materials and Methods: A retrospective study was conducted over a period of 5 years (January 2016–January 2021), comprising 85 ATs of skin diagnosed in the Department of Pathology, Sri Devaraj URS Medical College, Kolar, Karnataka, India. All the consecutively reported AT cases were reviewed and reclassified as ATs arising from sebaceous glands, hair follicles or sweat glands. The concordance of clinical and histopathological diagnosis was also assessed. Results: Most of the ATs were benign, with the head and neck being the most common location (61.15%), followed by the trunk (22.3%). Nearly 39% of the tumours were of hair follicle differentiation, 30% sweat gland differentiation and sebaceous gland tumours accounted for 31%. The most common varieties of tumours encountered in the present study included sebaceous cysts and pilomatricoma. The concordance between the clinical and histopathological diagnosis was found to be 50% approximately. Conclusion: Histopathology is the gold standard for diagnosing ATs as they are often misdiagnosed clinically.

Introduction: Adnexal skin tumours are a heterogeneous group of uncommon tumours usually misdiagnosed clinically due to a huge variety of types and their variants. Histopathology usually helps in establishing the diagnosis. The study was conducted to analyse the morphological, clinical and histological features of adnexal tumours (ATs) of the skin at our centre over a period of 5 years. Materials and Methods: A retrospective study was conducted over a period of 5 years (January 2016–January 2021), comprising 85 ATs of skin diagnosed in the Department of Pathology, Sri Devaraj URS Medical College, Kolar, Karnataka, India. All the consecutively reported AT cases were reviewed and reclassified as ATs arising from sebaceous glands, hair follicles or sweat glands. The concordance of clinical and histopathological diagnosis was also assessed. Results: Most of the ATs were benign, with the head and neck being the most common location (61.15%), followed by the trunk (22.3%). Nearly 39% of the tumours were of hair follicle differentiation, 30% sweat gland differentiation and sebaceous gland tumours accounted for 31%. The most common varieties of tumours encountered in the present study included sebaceous cysts and pilomatricoma. The concordance between the clinical and histopathological diagnosis was found to be 50% approximately. Conclusion: Histopathology is the gold standard for diagnosing ATs as they are often misdiagnosed clinically. [ABSTRACT FROM AUTHOR]

BackgroundPyoderma gangrenosum (PG) is a debilitating ulcerative skin disease that is one of the most common associated diseases seen in patients with inflammatory bowel disease and rheumatoid arthritis. Although PG is classified as a neutrophilic dermatosis, its pathophysiology is poorly understood.ObjectiveUse data obtained from patient-reported histories, immunohistochemistry, and gene expression analysis to formulate a hypothesis on PG pathophysiology.MethodsTen PG patients participated and answered questions about new ulcer formation. Skin biopsies of healed prior ulcers and adjacent normal skin were obtained from four patients for immunohistochemistry. Scars from healthy patients and patients with discoid lupus were used as additional controls. New onset PG papules were analyzed using immunohistochemistry and gene expression analysis via quantitative real-time PCR.ResultsAll PG patients reported that healed sites of previous ulceration are refractory to re-ulceration. Simultaneous biopsies of healed and uninvolved skin triggered ulceration only in the latter. On immunohistochemistry, healed PG scars showed complete loss of pilosebaceous units, which were present in normal skin, and to a lesser extent in control scars, and discoid scars. Early PG papules showed perivascular and peripilosebaceous T cell infiltrates, rather than neutrophils. These early inflammatory events were dominated by increased gene expression of CXCL9, CXCL10, CXCL11, IL-8, IL-17, IFNG, and IL-36G and transcription factors consistent with Th1 phenotype.LimitationsSmall sample size was the main limitation.ConclusionWe put forth the hypothesis that PG is a T cell response resulting in the destruction of pilosebaceous units.

Pyoderma gangrenosum (PG) is a rare entity that is characterized by infiltration of neutrophils into the dermis, causing the formation of rapidly enlarging, painful and necrotic skin ulcers. The pathophysiology of PG is still poorly understood. However, genetic, autoimmune and autoinflammatory mechanisms have been proposed that could potentially explain the etiology of this ulcerating skin disorder. Early diagnosis and treatment are key, as the disease course is rapidly progressive and can leave disfiguring, cribriform scars. However, the diagnosis of PG proves difficult, firstly because there are multiple variants of the disease and secondly because it is a clinical diagnosis and can appear similar to that of other diseases such as vasculitis, skin/soft tissue infections and malignancy. Additionally, there are no official diagnostic criteria to aid in the recognition of PG, which often leads to significant delays in diagnosis. The treatment of PG consists in immunosuppression. However, due to a lack of standardized guidelines, therapeutic regimens are usually dependent upon the individual clinician’s experience and are based on little evidence. Knowledge of the clinical features and pathophysiology of PG can aid in early diagnosis and targeted treatment strategies, which in turn results in improved patient outcomes.

Folliculosebaceous Cystic Hamartoma (FSCH) is an uncommon cutaneous hamartomatous lesion. It is basically a tumour like malformations exhibiting abnormal overgrowth of biphasic elements i.e., epithelial and mesenchymal components that are normally found in the skin. Few other hamartomas of pilosebaceous origin are trichofolliculoma, trichodiscoma, fibrofolliculoma and pilar sheath acanthoma. Though distinct, this entity shares similar histological features to Sebaceous Trichofolliculoma (STF). Hence, a proper histological examination is must in differentiating it from STF and other clinical and histological entities. Authors hereby, describes a case of FSCH in a 37-year-old male who presented with a slow growing cystic mass on his left earlobe, an uncommon location for such lesion. The mass was excised, and a detailed histological evaluation showed a characteristic multinodular growth pattern with lobules of pilosebaceous glands forming nodules around cystically dilated follicular infundibular structures. No hair shafts were seen in the cystic cavity ruling out differential diagnosis of sebaceous hyperplasia which could have been a close mimic. The intervening stroma revealed dense collagen, sheets and lobules of adipocytes, many vascular channels filled with fibrinous deposits. Perivascular adipocytes were also noted along with few nerve tissues (perineurium). A detailed clinicopathological work-up helped in arriving at a final diagnosis of FSCH with neural component. The patient was doing well till last six months of follow-up. No recurrence of similar lesion was noted in the patient.

Pyoderma gangrenosum (PG) is a rare entity that is characterized by infiltration of neutrophils into the dermis, causing the formation of rapidly enlarging, painful and necrotic skin ulcers. The pathophysiology of PG is still poorly understood. However, genetic, autoimmune and autoinflammatory mechanisms have been proposed that could potentially explain the etiology of this ulcerating skin disorder. Early diagnosis and treatment are key, as the disease course is rapidly progressive and can leave disfiguring, cribriform scars. However, the diagnosis of PG proves difficult, firstly because there are multiple variants of the disease and secondly because it is a clinical diagnosis and can appear similar to that of other diseases such as vasculitis, skin/soft tissue infections and malignancy. Additionally, there are no official diagnostic criteria to aid in the recognition of PG, which often leads to significant delays in diagnosis. The treatment of PG consists in immunosuppression. However, due to a lack of standardized guidelines, therapeutic regimens are usually dependent upon the individual clinician's experience and are based on little evidence. Knowledge of the clinical features and pathophysiology of PG can aid in early diagnosis and targeted treatment strategies, which in turn results in improved patient outcomes. [ABSTRACT FROM AUTHOR]

Acne vulgaris is a common, inflammatory and multifactorial disease of the pilosebaceous unit that primarily affects adolescents; however, it can be found at any age. When it occurs between birth and 12 years of age it is called pediatric acne, which based on the age at onset has been categorized into neonatal, infantile, middle childhood and preadolescent acne. The importance of this categorization lies in the etiopathogenic processes involved, course, complications and prognosis. Neonatal acne coexisting in the first 8 weeks of life has an excellent prognosis and does not require treatment. Infantile acne occurs from 8 weeks to 1 year; most of them course without complications and have the implication of severe acne in adolescence. Middle childhood acne appears between 1 and 7 years, a period in which there are virtually no adrenal or gonadal hormones, so an underlying endocrinopathy should be investigated. In contrast, preadolescent acne, between 7 and 12 years of age, is very common and considered normal. However, in any patient with symptoms and signs of hyperandrogenism, an endocrinologic disorder should be investigated. Knowledge of childhood acne will allow the treating physician or pediatrician to suspect the existence of an underlying disease. The influence of the Western diet on the severity of acne has been demonstrated and is becoming more relevant. Prompt and effective treatment of acne reduces the psychosocial impact on the patient. However, future research is needed to determine this effect in the pediatric patient. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) is a well-established bedside imaging modality that allows analysis of skin structures in a non-invasive way. Automated OCT analysis of skin layers is of great relevance to study dermatological diseases. In this paper, an approach to detect the epidermal layer along with the follicular structures in healthy human OCT images is presented. To the best of the authors' knowledge, the approach presented in this paper is the only epidermis detection algorithm that segments the pilosebaceous unit, which is of importance in the progression of several skin disorders such as folliculitis, acne, lupus erythematosus, and basal cell carcinoma. The proposed approach is composed of two main stages. The first stage is a Convolutional Neural Network based on U-Net architecture. The second stage is a robust post-processing composed by a Savitzky-Golay filter and Fourier Domain Filtering to fully define the borders belonging to the hair follicles. After validation, an average Dice of 0.83 ± 0.06 and a thickness error of 10.25 μm is obtained on 270 human skin OCT images. Based on these results, the proposed method outperforms other state-of-the-art methods for epidermis segmentation. It demonstrates that the proposed image segmentation method successfully detects the epidermal region in a fully automatic way in addition to defining the follicular skin structures as main novelty.

Sebaceous glands are sebum‐secreting components of pilosebaceous units. The embryological development of the sebaceous gland follows that of the hair follicle and epidermal tissue, beginning between weeks 13 and 16 of fetal development. New sebaceous glands do not normally develop following birth, but their size increases with age. Sebocytes express a multitude of hormone receptors and are heavily regulated to secrete sebum by androgens. There is a large increase of sebum excretion at birth and again at puberty, until approximately age 17. In adulthood, sebum production remains stable and declines to zero in postmenopausal women and in men aged 60‐70. Besides the production and release of sebum, sebaceous glands function to lubricate the skin and hair, provide thermoregulation, and exhibit antimicrobial activity. Research has shown sebaceous glands to possess the cellular capability to transcribe genes necessary for androgen metabolism. Dysfunction of the sebaceous gland can be seen primarily in steatocystoma simplex and multiplex, sebaceous gland hyperplasia, sebaceoma, sebaceous adenoma, sebaceous carcinoma, nevus sebaceus, and folliculosebaceous cystic hamartoma. Sebaceous glands are secondarily involved in acne vulgaris, seborrheic dermatitis, and androgenic alopecia. [ABSTRACT FROM AUTHOR]

In 2018, Schneider and Zouboulis analysed the available tools for studying sebaceous gland pathophysiology in vitro. Since then, the interest in this field remains unbroken, as demonstrated by recent reviews on sebaceous gland physiology, endocrinology and neurobiology, the role of sebaceous glands beyond acne, and several original works on different areas of sebaceous gland function, including sebaceous lipogenesis. Landmark developments in the first part of the 30‐year modelling research dedicated to the sebaceous gland, which is considered by several scientists as the brain of the skin, were the short‐term culture of human sebaceous glands, the culture of human sebaceous gland cells and the development of immortalized sebaceous gland cell lines exhibiting characteristics of normal sebocytes. On the other hand, current developments represent the establishment of sebaceous gland spheroids, the 3D‐SeboSkin model of viable skin explants ex vivo, the combination of culture‐expanded epidermal stem cells of mice and adult humans to form de novo hair follicles and sebaceous glands, when they are transplanted into excisional wounds in mice, and 3D‐printed scaffolds coated with decellularized matrix of adipose‐derived mesenchymal stromal cells and SZ95 sebocytes. These novel tools may become useful platforms for better understanding of cellular and molecular mechanisms governing sebocyte biology and sebaceous gland homeostasis, such as the changes in sebum synthesis and composition, the infundibular differentiation and the influence of the innate immunity and the cutaneous microbiome and for identifying potential therapeutic targets of skin diseases affecting the sebaceous glands. [ABSTRACT FROM AUTHOR]

Background: Basic histological knowledge of the different components of the pilosebaceous unit is important in the pathologic interpretation of hair disorders. Aim and Objectives: Due to paucity of detailed microscopic features and photomicrographs of the pilosebaceous unit (PSU) at one place, this study aimed to review the normal developmental stages and provide microscopic features, along with the photomicrographs of different components of the pilosebaceous unit that could prove useful in certain hair conditions and therapeutic procedures. Materials and Methods: Tissue samples were obtained from the site of experimentally induced incisional and excisional skin wounds in such a way that parts of normal skin around these healing skin wounds were included. These samples were processed for routine paraffin serial sectioning. These sections were stained with routine and special stains. Histological features were recorded under different magnification of the Trinocular microscope. Study Limitation: The study presented is a part of another research study related to skin wound healing in adult albino rats. Results: The general structure of the pilosebaceous unit was shown by routine Haematoxylin and Eosin staining. While the presence and distribution of collagen fibres were demonstrated by Masson's Trichrome and PicroSirius Red with Fast Green staining, type III collagen (reticular) fibres were observed in PicroSirius Red with Silver Nitrate staining and that of elastin fibres were demarcated by Aldehyde Fuchsin with Fast Green staining method. Conclusion: In certain conditions and procedures, such as hair disorders, hair transplantation, and follicular drug delivery, where detailed histology of the pilosebaceous unit is required, the present study wherein many special stains were used could prove very useful for quick and easy identification of different types of cells and fibres associated with the pilosebaceous unit. [ABSTRACT FROM AUTHOR]

The acne disease is a disorder of pilosebaceous units and highly common which is chronic and recurring and is distinguished due to the development of comedones (open and closed) and papules along with the formation of pustules, nodules, and cysts. Acne afflicts adolescent population mostly and adults occasionally with 9.4% global prevalence. The pathogenesis is multifaceted which involves increased androgen production (hyperseborrhea) followed by pilosebaceous unit hyperkeratinization, colonization of Propionibacterium acnes, along with releasing the inflammatory mediators. The key hormones such as androgens, insulin, insulin-like growth factor are responsible for the acne vulgaris progression and contiguous with various mostly preventable and modifiable risk factors, such as environmental factors, genetic predisposition, lifestyle factors and drug use by a successful management. Due to the exceptional patient prerequisites and its complex clinical presentation acne possesses various treatment challenges. There are various treatment options available, but the available guidelines are insufficient to make evidence-based recommendations. The treatment includes topical therapy such as benzoyl peroxide, antibiotics and retinoids, systemic retinoid and antibiotics, hormonal, and various adjuvant treatment modalities like comedo removal, laser, and light therapy intralesional injections and chemical peels. The present review focuses on a general overview of acne vulgaris and its treatment modalities available presently. [ABSTRACT FROM AUTHOR]

Eccrine sweat glands and hair follicles are two primary skin appendages that serve different functions. Although the two appendages exhibit unique morphological patterns in adults, it is difficult to distinguish them morphologically in the early stages of development and regeneration. To research and compare the development, differentiation and regeneration between eccrine sweat glands and hair follicles/pilosebaceous units, specific antigen markers must be found first. Human skin samples were fixed, paraffin-embedded, and cut. The expression of K5, K7, K8, K14, K27, K31, K73, AE13, α-smooth muscle actin (α-SMA), epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), Na+/K+-ATPase α and Na+–K+–2Cl cotransporter 1 (NKCC1) in eccrine sweat glands, hair follicles and sebaceous glands was detected by immunofluorescence staining. The results showed that eccrine sweat glands expressed K5, K7, K8, K14, K31, α-SMA, CEA, EMA, Na+/K+-ATPase α and NKCC1, but did not express K27, K73 or K31. Hair follicles expressed K5, K8, K14, K27, K31, K73, α-SMA and AE13, but did not express K7, CEA, Na+/K+-ATPase α or NKCC1. Sebaceous glands expressed K5, K14, K73, and EMA, but did not express K7, K8, K31, α-SMA, CEA, EMA, Na+/K+-ATPase α or NKCC1. We concluded that K7, CEA, Na+/K+-ATPase and NKCC1 can be used as specific markers for eccrine sweat glands, K27 and AE13 can be used as specific markers for hair follicles, and K73 can be used as a specific marker for pilosebaceous unit. These specific markers may contribute to differentiate between eccrine sweat glands and hair follicle/pilosebaceous units. [ABSTRACT FROM AUTHOR]

Eruptive vellus hair cysts are rare benign tumors of pilosebaceous unit with vellus hairs, which appear in childhood or young adults. Their etio-pathogenesis is poorly known. A review of the literature shows that eruptive vellus hair cysts (EVHC) might be inherited as autosomal dominant or acquired, and might be associated with other genodermatoses like pachyonychia congenita and anhidrotic ectodermal dysplasia. Although it is a benign tumor of pilosebaceous unit, this condition is rather difficult to treat. Here we report a case of 23 years old female with multiple, asymptomatic, slate-grey to bluish papules on face and ears for last 5 years, with a positive family history of similar lesions in other siblings. To the best of our knowledge, this is the first case of autosomal dominant facial variant of eruptive vellus hair cysts to be published from Pakistan. [ABSTRACT FROM AUTHOR]

Background: Cutibacterium acnes has been identified as one of the main triggers of acne. However, increasing knowledge of the human skin microbiome raises questions about the role of other skin commensals, such as Staphylococcus epidermidis, in the physiopathology of this skin disease.Summary: This review provides an overview of current knowledge of the potential role of S. epidermidis in the physiopathology of acne. Recent research indicates that acne might be the result of an unbalanced equilibrium between C. acnes and S. epidermidis,according to dedicated interactions. Current treatments act on C. acnesonly. Other treatment options may be considered, such as probiotics derived from S. epidermidis to restore the naturally balanced microbiota or through targeting the regulation of the host's AMP mediators. Key Messages: Research seems to confirm the beneficial role of S. epidermidis in acne by limiting C. acnes over-colonisation and inflammation. [ABSTRACT FROM AUTHOR]

Background: acne vulgaris is a chronic inflammatory disease of the skin that affects the individuals of all ages, especially adolescents. An association between serum zinc levels and acne vulgaris have been reported in some studies. Objective: the aim of our study was to estimate serum zinc level in patients with acne vulgaris and healthy subjects and its association with severity of disease. Patients and Methods: this study was conducted on 60 patients (subdivided into 4 groups according to severity of disease according to Global Acne Grading System) and 60 normal individuals as a control group. Results: there was highly significantly statistical difference between all patients and control groups as regard serum zinc level (mean of serum zinc level in patients and control groups were 49.85 ±19.61 and 63.46 ± 22.95 respectively, p=<0.001). Conclusion: it is concluded that zinc deficiency in acne patients could be one of the causes of acne and also that zinc levels may not be related to the severity. [ABSTRACT FROM AUTHOR]

The uppermost aspect of the hair follicle, known as the infundibulum or hair canal, provides a passageway for hair shaft egress and sebum secretion. Recent studies have indicated that the infundibulum and sebaceous ducts are lined by molecularly distinct differentiated cells expressing markers including Keratin 79 and Gata6. Here, we ablated Gata6 from the skin and observed dilation of both the hair canal and sebaceous ducts, independent of gender and hair cycle stage. Constitutive loss of Gata6 yielded only a mild delay in depilation‐induced entry into anagen, while unperturbed mutant mice possessed overtly normal skin and hair. Furthermore, we noted that Keratin 79 and Gata6 expression and localization did not depend upon each other. Our findings implicate Gata6 in maintaining the upper hair follicle and suggest that regulation of this transcription factor may be compromised in pathologies such as acne or infundibular cystic diseases that are characterized by abnormal expansion of this follicular domain. [ABSTRACT FROM AUTHOR]

Acne vulgaris (AV) is the familiar chronic skin ailment affecting most of the individuals. This multifarious, disease involves the bacterium gram-positive, anaerobic Propionibacterium acnes (P. acnes) which resides on skin microflora, and participated in acne inflammation and acne lesions. The object of this review is to discuss presently available in vitro, ex vivo, and in vivo models to evaluate the cosmetic formulations that are developed for dealing and prevention of acne formation. These various available models offer new chances for further research on biologically active materials, drugs & pharmaceutical as well as cosmetics for acne treatment. [ABSTRACT FROM AUTHOR]

Zein is a naturally occurring corn protein having similarity to skin keratin. Owing to its hydrophobicity and biodegradability, zein nanocarriers are promising drug delivery vehicles for hydrophobic dermatological drugs. In this study, zein-based nanocapsules (ZNCs) were exploited for the first time as dermal delivery carriers for flutamide (FLT), an antiandrogen used for the management of pilosebasceous unit disorders. FLT-loaded ZNC of appropriate particle size and negative surface charge were prepared by nanoprecipitation method. The dermal permeation and skin retention of FLT from ZNCs were studied in comparison to corresponding nanoemulsion (NE) and hydroalcoholic drug solution (HA). ZNCs showed a significantly lower permeation flux compared to NE and HA while increasing the skin retention of FLT. Confocal laser scanning microscopy (CLSM) demonstrated the follicular localization of the fluorescently labeled NCs. The incorporation of NCs in chitosan gel or Carbomer® 934 gel was studied. Carbomer® gel increased the skin retention of FLT compared to chitosan gel. Accordingly, Carbomer® hydrogel embedding FLT-loaded ZNCs is a promising inexpensive, biocompatible dermal delivery nanocarrier for localized therapy of PSU disorders suitable for application on oily skin. [ABSTRACT FROM AUTHOR]

Abstract: Terence Kealey first pioneered the isolation and organ maintenance of human eccrine and sebaceous glands in the early to mid‐1980. This led to subsequent methods describing the isolation and culture of human hair follicles, the human pilosebaceous unit as well as the sebaceous duct. The importance of these models in the study of the biology of human skin glands and appendages has been demonstrated in numerous publications and their importance as models for animal replacement, refinement and reduction (3Rs) is increasingly important. In particular, in vitro (ex vivo) hair follicle culture has played a significant part in helping elucidate the role of signalling molecules in regulating hair growth and hair fibre formation and has been especially useful in understanding metabolic aspects of hair growth. However, obtaining sufficient numbers of hair follicles is becoming increasingly difficult as plastic surgery becomes less invasive and smaller skin samples provided. There is therefore an urgent requirement for the next generation of in vitro models using cell lines and tissue engineering, and this has led to the development of immortalised cell lines as well as attempts to model hair follicle embryogenesis in vitro and development of skin on a chip. [ABSTRACT FROM AUTHOR]

BackgroundPyoderma gangrenosum (PG) is a debilitating ulcerative skin disease that is one of the most common associated diseases seen in patients with inflammatory bowel disease and rheumatoid arthritis. Although PG is classified as a neutrophilic dermatosis, its pathophysiology is poorly understood.ObjectiveUse data obtained from patient-reported histories, immunohistochemistry, and gene expression analysis to formulate a hypothesis on PG pathophysiology.MethodsTen PG patients participated and answered questions about new ulcer formation. Skin biopsies of healed prior ulcers and adjacent normal skin were obtained from four patients for immunohistochemistry. Scars from healthy patients and patients with discoid lupus were used as additional controls. New onset PG papules were analyzed using immunohistochemistry and gene expression analysis via quantitative real-time PCR.ResultsAll PG patients reported that healed sites of previous ulceration are refractory to re-ulceration. Simultaneous biopsies of healed and uninvolved skin triggered ulceration only in the latter. On immunohistochemistry, healed PG scars showed complete loss of pilosebaceous units, which were present in normal skin, and to a lesser extent in control scars, and discoid scars. Early PG papules showed perivascular and peripilosebaceous T cell infiltrates, rather than neutrophils. These early inflammatory events were dominated by increased gene expression of CXCL9, CXCL10, CXCL11, IL-8, IL-17, IFNG, and IL-36G and transcription factors consistent with Th1 phenotype.LimitationsSmall sample size was the main limitation.ConclusionWe put forth the hypothesis that PG is a T cell response resulting in the destruction of pilosebaceous units.

Introduction: Acne Vulgaris (AV) is a common inflammatory disease of pilosebaceous units. Liver X Receptor-α (LXR-α) is a ligand activated transcription factor. It controls transcription of genes involved in lipid and fatty acid synthesis. Cyclooxygenase 2 (COX2) is a rate limiting enzyme in prostaglandin synthesis. It plays important role in inflammation. Aim: To evaluate the immunohistochemical expression of LXR-α and COX2 in acne vulgaris skin biopsies to explore their possible pathogenic role in this disease. Materials and Methods: Sixty five subjects were included (45 cases with AV and 20 age and gender-matched healthy controls). Skin biopsies were taken from lesional and perilesional skin of cases and from site-matched areas of control subjects. The evaluation of LXR-α and COX2 was done using immunohistochemical technique. Data were collected, tabulated and statistically analysed using a personal computer with “(SPSS) version 11” program. Chi-square test was used to study the association between qualitative variables. Mann– Whitney test was used for comparison between quantitative variables. Student’s t-test was used for comparison between two groups having quantitative variables. Spearman’s coefficient was used to study the correlation between two different variables. Differences were considered statistically significant with p