Koebner phenomenon leading to the formation of new psoriatic lesions: evidences and mechanisms

Redox Pathogenesis in Rheumatic Diseases

Despite being some of the most anecdotally well-known roads to pathogenesis, the mechanisms governing autoimmune rheumatic diseases are not yet fully understood. The overactivation of the cellular immune system and the characteristic development of autoantibodies have been linked to oxidative stress. Typical clinical manifestations, such as joint swelling and deformities and inflammation of the skin and internal organs, have also been connected directly or indirectly to redox mechanisms. The differences in generation and restraint of oxidative stress provide compelling evidence for the broad variety in pathology among rheumatic diseases and explain some of the common triggers and discordant manifestations in these diseases. Growing evidence of redox mechanisms in pathogenesis has provided a broad array of new potential therapeutic targets. Here, we explore the mechanisms by which oxidative stress is generated, explore its roles in autoimmunity and end-organ damage, and discuss how individual rheumatic diseases exhibit unique features that offer targets for therapeutic interventions.

The Immunology of Psoriasis-Current Concepts in Pathogenesis

Psoriasis is one of the most common inflammatory skin diseases with a chronic, relapsing-remitting course. The last decades of intense research uncovered a pathological network of interactions between immune cells and other types of cells in the pathogenesis of psoriasis. Emerging evidence indicates that dendritic cells, TH17 cells, and keratinocytes constitute a pathogenic triad in psoriasis. Dendritic cells produce TNF-α and IL-23 to promote T cell differentiation toward TH17 cells that produce key psoriatic cytokines IL-17, IFN-γ, and IL-22. Their activity results in skin inflammation and activation and hyperproliferation of keratinocytes. In addition, other cells and signaling pathways are implicated in the pathogenesis of psoriasis, including TH9 cells, TH22 cells, CD8+ cytotoxic cells, neutrophils, γδ T cells, and cytokines and chemokines secreted by them. New insights from high-throughput analysis of lesional skin identified novel signaling pathways and cell populations involved in the pathogenesis. These studies not only expanded our knowledge about the mechanisms of immune response and the pathogenesis of psoriasis but also resulted in a revolution in the clinical management of patients with psoriasis. Thus, understanding the mechanisms of immune response in psoriatic inflammation is crucial for further studies, the development of novel therapeutic strategies, and the clinical management of psoriasis patients. The aim of the review was to comprehensively present the dysregulation of immune response in psoriasis with an emphasis on recent findings. Here, we described the role of immune cells, including T cells, B cells, dendritic cells, neutrophils, monocytes, mast cells, and innate lymphoid cells (ILCs), as well as non-immune cells, including keratinocytes, fibroblasts, endothelial cells, and platelets in the initiation, development, and progression of psoriasis.

The role of smoking in psoriasis

Psoriasis has a clear and strong connection with smoking in both its pathogenesis and clinical course. Smoking can cause a serious worsening of both the disease itself and the systemic complications such as cardiovascular events, psoriatic arthritis (PsA), cancer and depression. Smoking also seems to alter the gut microbiota and thus promote psoriasis itself. The aim of our article is to review all the most interesting discoveries on its role and thus provide a good picture of the current state of knowledge. Furthermore, we provide some alternative and healthier coping mechanisms for stress and depression related to the disease such as exercise, meditation, balneotherapy and acupuncture.

Acquired diffuse palmoplantar erythema with keratoderma in Chinese patients with pustular psoriasis: A predictor for IL36 receptor antagonist c.115+6T>C mutation?

Several studies have suggested that mutation of the interleukin 36 receptor antagonist gene (IL36RN) is related to generalized pustular psoriasis (GPP), and the presence of IL36RN mutation may affect the clinical manifestations and treatment responses. However, genetic testing is not routinely available in clinical practice for the diagnosis of GPP. Previously, GPP patients with acrodermatitis continua of Hallopeau (ACH) were found to have a high percentage of carrying IL36RN mutation. In this study, we reported six patients with pustular psoriasis presenting as diffuse palmoplantar erythema with keratoderma among 60 patients who carried IL36RN mutation. ACH was present in five patients and five patients had acute flare of GPP. This unique presentation may serve as a predictor for IL36RN mutation in patients with pustular psoriasis, similar to ACH.

The effect of autoimmune skin disorders on post-operative outcomes following arthroplasty

INTRODUCTION

The impact of autoimmune skin disorders on post-operative outcomes after TJA is conflicting and studies are limited by small sample sizes. The purpose of this study is to analyze a range of common autoimmune skin disorders and identify whether an increased risk of post-operative complication exists after total joint arthroplasty.

METHODS

Data was collected from NIS database for patients diagnosed with autoimmune skin disorder (psoriasis, lupus, scleroderma, atopic dermatitis) and who underwent total hip arthroplasty (THA), total knee arthroplasty (TKA), or other TJA (shoulder elbow, wrist, ankle) between 2016 and 2019. Demographic, social, and comorbidity data was collected. Multivariate regression analyses were performed to assess the independent influence of autoimmune skin disorder on each post-operative outcome including implant infection, transfusion, revision, length of stay, cost, and mortality.

RESULTS

Among 55,755 patients with autoimmune skin disease who underwent TJA, psoriasis was associated with increased risk of periprosthetic joint infection following THA (odds ratio 2.44 [1.89-3.15]) and increased risk of transfusion following TKA (odds ratio 1.33 [1.076-1.64]). Similar analyses were performed for systemic lupus erythematosus, atopic dermatitis, and scleroderma, however no statistically significant associations were observed in any of the six collected post-operative outcomes.

CONCLUSION

This study suggests psoriasis is an independent risk factor for poorer post-operative outcomes following total joint arthroplasty, however similar risk was not observed for other autoimmune skin disorders such as lupus, atopic dermatitis, or scleroderma.

The biological basis of disease recurrence in psoriasis

Despite the amazing advances produced in our understanding of the pathogenesis of psoriasis, which have led to a therapeutic revolution, our knowledge of the mechanisms of relapse and elicitation of lesions is just starting to unravel. This narrative review tours the different cell types and mechanisms involved in the priming, maintenance, and relapse of psoriasis vulgaris. Our discussion includes dendritic cells, T cells, tissue resident memory cells and mast cells, with a foray into the epigenetic mechanisms of inflammatory memory in keratinocytes. Increasing knowledge is providing a glimpse of a potential therapeutic window of opportunity in psoriasis, providing long term remission and eventual modification of the natural history of the disease.

Biological therapies for the treatment of psoriasis in pediatrics

INTRODUCTION

Psoriasis is a multifactorial, immune-mediated condition with predominant skin involvement. It may develop at any age. In one-third of patients, the first symptoms of psoriasis start during childhood or adolescence. A marked impairment of the quality of life of patients and their caregivers is often associated.

AREAS COVERED

Databases including PubMed and Clinicaltrials.gov were used to identify clinical studies involving pediatric patients with psoriasis. In the last few years, the implementation of therapy with drugs targeting cytokines like interleukin (IL)-12/23 and IL-17A has expanded the number of available therapeutic options in pediatric psoriasis. This review focuses on the latest evidence on the clinical efficacy and safety profile of drugs licensed for severe pediatric psoriasis.

EXPERT OPINION

Increasing knowledge about the pathogenetic mechanisms underlying pediatric psoriasis is leading to an improvement in disease management. Effective treatment is crucial in patients affected with moderate to severe disease to reduce the burden of the disease and avoid stigmatization. The treatment of pediatric psoriasis remains challenging for specific clinical subtypes, when difficult areas are involved, after resistance to multiple treatments, and when psoriatic arthritis is associated. A personalized approach and a thorough understanding of the disease are required to advance pediatric psoriasis care.

Implications of interleukin-17 in psoriatic lesions as Koebner phenomenon caused by recurrent occupational burns

The Koebner phenomenon (KP) is the emergence of new lesions in an uninvolved skin area caused by different types of stimulations, including mechanical stress, chemical stress, trauma, or injury. KP affects patients with certain skin diseases and is frequently observed in patients with psoriasis. We report the case of a 43-year-old obese male welder who developed psoriatic lesions only in areas of repeated burns due to his occupation. He was repeatedly exposed to mild burns in his anterior neck and the periorbital region as he was welding without shield protection. Subsequently, erythema appeared in the same region. Skin appearance and skin biopsy suggested psoriasis vulgaris (PV), and immunohistochemical analysis of anti-interleukin (IL)-17, a crucial element in the development of PV, showed the positivestained cells. The anti-IL-17 staining was prominent around the thickened epidermis as psoriatic lesions. IL-17 produced by T helper 17 cells stimulates keratinized cells and promotes chemokine secretion involved in neutrophil migration. Our case showed that patients, even without a history of PV, may have a risk of developing KP and PV via the enhanced production of IL- 17 locally in the repeated burn area. No recurrence of skin symptoms was observed when the patient used a fully defensive shield during welding.

Review of natural compounds for potential psoriasis treatment

Psoriasis represents an immune-mediated disease with an unclear cause that's marked by inflammation triggered by dysfunction in the immune system, which results in inflammation in various parts of the skin. There could be obvious symptoms, such as elevated plaques; these plaques may appear differently depending on the type of skin. This disease can cause inflammation in the elbows, lower back, scalp, knees, or other regions of the body. It can begin at any age, although it most commonly affects individuals between the ages of 50 and 60. Specific cells (such as T cells) have been observed to play an obvious role in the pathogenesis of psoriasis, in addition to specific immunological molecules such as TNF-, IL-12, IL-23, IL-17, and other molecules that can aid in the pathogenesis of psoriasis. So, during the past two decades, biologists have created chemical drugs that target these cells or molecules and therefore prevent the disease from occurring. Alefacept, efalizumab, Adalimumab, Ustekinumab, and Secukinumab are a few examples of chemical drugs. It was discovered that these chemical drugs have long-term side effects that can cause defects in the patient's body, such as the development of the rare but life-threatening disorder progressive multifocal leukoencephalopathy (PCL). Its rapidly progressive infection of the central nervous system caused by the JC virus and other drugs may cause increased production of neutralising anti-drug antibodies (ADA) and the risk of infusion reactions like pruritus, flushing, hypertension, headache, and rash. So, our context intends to talk in our review about natural products or plants that may have therapeutic characteristics for this disease and may have few or no side effects on the patient's body.

Pharmaco-Omics in Psoriasis: Paving the Way towards Personalized Medicine

The emergence of high-throughput approaches has had a profound impact on personalized medicine, evolving the identification of inheritable variation to trajectory analyses of transient states and paving the way for the unveiling of response biomarkers. The utilization of the multi-layered pharmaco-omics data, including genomics, transcriptomics, proteomics, and relevant biological information, has facilitated the identification of key molecular biomarkers that can predict the response to therapy, thereby optimizing treatment regiments and providing the framework for a tailored treatment plan. Despite the availability of multiple therapeutic options for chronic diseases, the highly heterogeneous clinical response hinders the alleviation of disease signals and exacerbates the annual burden and cost of hospitalization and drug regimens. This review aimed to examine the current state of the pharmaco-omic approaches performed in psoriasis, a common inflammatory disease of the skin. We sought to identify central studies that investigate the inter-individual variability and explore the underlying molecular mechanisms of drug response progression via biological profiling in psoriatic patients administered with the extended therapeutic armamentarium of psoriasis, incorporating conventional therapies, small molecules, as well as biological drugs that inhibit central pathogenic cytokines involved in the disease pathogenesis.

The Role of Mast Cells in the Induction and Maintenance of Inflammation in Selected Skin Diseases

Under physiological conditions, skin mast cells play an important role as guardians that quickly react to stimuli that disturb homeostasis. These cells efficiently support, fight infection, and heal the injured tissue. The substances secreted by mast cells allow for communication inside the body, including the immune, nervous, and blood systems. Pathologically non-cancerous mast cells participate in allergic processes but also may promote the development of autoinflammatory or neoplastic disease. In this article, we review the current literature regarding the role of mast cells in autoinflammatory, allergic, neoplastic skin disease, as well as the importance of these cells in systemic diseases with a pronounced course with skin symptoms.

Investigating the epidemiological relationship between vitiligo and psoriasis: a population-based study

BACKGROUND

The association of vitiligo with psoriasis is inconsistent in the current literature.

OBJECTIVE

To assess the bidirectional association between vitiligo and psoriasis.

METHODS

A population-based study was performed to compare vitiligo patients (n = 20,851) with age-, sex- and ethnicity-matched control subjects (n = 102,475) regarding the incidence of new-onset and the prevalence of preexisting psoriasis. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were calculated by cox regression and logistic regression, respectively.

RESULTS

The incidence rate of new-onset psoriasis was estimated at 7.9 (95% CI 6.4-9.7) and 4.7 (95% CI 4.1-5.3) cases per 10,000 person-years among patients with vitiligo and controls, respectively. Patients with vitiligo experienced an increased risk of psoriasis (fully-adjusted HR 1.71; 95% CI 1.35-2.17; P < 0.001). On the other hand, the odds of vitiligo were only marginally elevated among patients with preexisting psoriasis (fully-adjusted OR 1.19; 95% CI 1.01-1.40; P = 0.051). Compared to other patients with vitiligo, those with vitiligo and comorbid psoriasis were older at the onset of the disease and had a greater prevalence of metabolic and cardiovascular comorbidities.

CONCLUSIONS

A diagnosis of vitiligo predisposes individuals to develop subsequent psoriasis. Clinicians managing dermatologic patients ought to be aware of this comorbidity. Further research is required to explicate the pathomechanism underlying this epidemiological observation.

Bioactive Lavandula angustifolia essential oil-loaded nanoemulsion dressing for burn wound healing. In vitro and in vivo studies

The aim of this study was to develop a dressing with bioactive lavender in a new form of nanoemulsion, and to verify its biosafety and effectiveness in burn wound healing. As part of this research, the composition of the bioactive carrier of lavender oil in the form of a nanoemulsion obtained using ultrasound was optimised. The mean particle size of the internal phase and polydispersity were determined using the dynamic light scattering method using a Zestasizer NanoZS by Malvern and using cryo-transmission electron microscopy (TEM). These studies confirmed that the selected formulation had a particle size of approximately 180 nm and remained stable over time. The preparation was also subjected to rheological analysis (viscosity approximately 480 mPa·s) and a pH test (approximately 6). A macroemulsion (ME) with the same qualitative composition was developed as a reference. Nanoformulations and MEs were tested for skin penetration using Raman spectroscopy in an in vitro model. Research has shown that both formulations deliver oil to living layers of the skin. Subsequently, studies were conducted to confirm the effect of lavender oil in emulsion systems on the mitigation of the inflammatory reaction and its pro-regenerative effect on the wound healing process in an in vitro cell culture model. The safe concentration of the oil in the emulsion preparation was also determined based on preliminary in vivo tests of skin sensitisation and irritation as well as an hemocompatibility test of the preparation.

Koebner Phenomenon in Kaposi's Sarcoma: A Large Single-Center Case Series and Review of Current Knowledge

BACKGROUND

occasional case reports have described the appearance of Kaposi's sarcoma (KS) on previously unaffected skin after incidental or accidental injury, but the association is probably under-reported.

OBJECTIVES

to present a large case series of patients suffering from Koebner phenomenon (KP) in KS and describe their main epidemiological, clinical, and therapeutic features.

METHODS

we have retrospectively analyzed our clinical and photographic records of 524 patients who had been diagnosed with KS between 2009 and 2021.

RESULTS

31 of 524 (6%) KS patients developed KP. Among these 31 patients, 24 (77%) had KS lesions after surgery, 4 (13%) after electrochemotherapy, laser therapy and cryotherapy, and 3 (10%) on areas affected by bullous diseases.

CONCLUSIONS

trauma, including surgery or other medical procedures, can trigger KS, underlying the importance of treatment options which cause the least injury to the skin.

Estradiol Regulates the Expression and Secretion of Antimicrobial Peptide S100A7 via the ERK1/2-Signaling Pathway in Goat Mammary Epithelial Cells

S100A7 has received extensive attention in the prevention and treatment of mastitis across a broad spectrum, yet there is a little information about its mechanism, especially in the immunomodulatory effects of estrogen. In the present study, based on the milk bacteriological culture (BC) of 30 dairy goats, the concentration of both estrogen and S100A7 in the BC-positive samples was not significantly different than in the BC-negative samples; the estrogen abundance in subclinical and clinical mastitis samples also showed only a limited difference; compared with healthy samples, the S100A7 abundance in subclinical mastitis samples differed little, while it was significantly decreased in clinical mastitis samples. Moreover, the relationship between estrogen and S100A7 was positive, and the regression equation was y = 0.3206x + 23.459. The goat mammary epithelial cells (gMECs) were isolated and treated with 1, 10, 100 nM E2 and/or 5 μg/mL lipopolysaccharide (LPS), respectively, for 6 h. Compared with control samples, 5 μg/mL LPS, 10 nM E2 and 100 nM E2 markedly induced S100A7 expression and secretion. More than separated treatment, the cooperation of LPS and E2 also significantly increased S100A7 expression, rather than S100A7 secretion. The p-ERK was up-regulated markedly with 100 nM E2 treatment, while the expression of p-JNK, p-p38 and p-Akt had little effect. The G protein-coupled estrogen receptor 1(GPER1) agonist G1 markedly induced S100A7 expression and secretion in gMECs, and the estrogen nuclear receptor antagonist ICI and GPER1 antagonist G15 significantly repressed this process. In conclusion, E2 binds to nuclear and membrane receptors to regulate the expression and secretion of S100A7 via the ERK1/2-signaling pathway in gMECs.

S100 Proteins as Novel Therapeutic Targets in Psoriasis and Other Autoimmune Diseases

Psoriasis is one of the most common inflammatory skin diseases affecting about 1-3% of the population. One of the characteristic abnormalities in psoriasis is the excessive production of antimicrobial peptides and proteins, which play an essential role in the pathogenesis of the disease. Antimicrobial peptides and proteins can be expressed differently in normal and diseased skin, reflecting their usefulness as diagnostic biomarkers. Moreover, due to their very important functions in innate immunity, members of host defense peptides and proteins are currently considered to be promising new therapeutic targets for many inflammatory diseases. Koebnerisin (S100A15) belongs to an S100 family of antimicrobial proteins, which constitute the multigenetic group of calcium-binding proteins involved in ion-dependent cellular functions and regulation of immune mechanisms. S100A15 was first discovered to be overexpressed in 'koebnerized' psoriatic skin, indicating its involvement in the disease phenotype and the same promising potential as a new therapeutic target. This review describes the involvement of antimicrobial peptides and proteins in inflammatory diseases' development and therapy. The discussion focuses on S100 proteins, especially koebnerisin, which may be involved in the underlying mechanism of the Köebner phenomenon in psoriasis, as well as other immune-mediated inflammatory diseases described in the last decade.

Biological Treatments for Pediatric Psoriasis: State of the Art and Future Perspectives

Psoriasis is a chronic systemic inflammatory disease that primarily affects the skin and is associated with multiple comorbidities with a considerable reduction in quality of life of affected patients. One-third of psoriasis cases begin in childhood and are associated with significant medical comorbidities such as obesity, metabolic syndrome, arthritis, and psychiatric disorders. In addition, because of its chronic nature and frequent relapses, psoriasis tends to require long-term treatment. Treatment of pediatric psoriasis usually involves the same methods used for adults. However, most treatments for pediatric psoriasis are used off-label, and research in this regard is still lacking. Targeted therapies involving the use of newly developed biologic drugs are also increasingly being applied to childhood psoriasis. This review summarizes the clinical features of pediatric psoriasis and focuses mainly on the updated concepts of pathogenesis and biological treatments of pediatric psoriasis.

The role of trauma and isomorphic reaction in the pathogenesis of psoriatic arthritis

The role of biomechanical stress and trauma in the initiation of inflammation of the joints and periarticular structures in psoriatic arthritis (PA) is currently not fully understood. Soft tissues and joints are the target for constant biomechanical stress and microtrauma, leading to inflammation. There is an opinion that this inflammation in PA is due to an analogue of the skin isomorphic reaction that develops in the skin of psoriatic patients in response to trauma. Some authors have called this reaction the deep Koebner phenomenon. It is assumed that the early, preclinical phase of psoriatic arthritis may be based on inflammation of the enthesis as a response to microtrauma, and explained by the proximity of the entheses and the articular membranes. Detection of early changes in entheses in psoriatic patients, including those who do not have complaints from the musculoskeletal system, is of great importance for the early diagnosis of psoriatic arthritis. In the literature review, the sources for the period 20102021 were studied, devoted to the role of the isomorphic reaction and microtraumatization in the pathogenesis of PA, as well as the role of various imaging methods for the early diagnosis of enthesitis in psoriatic patients.

α-Enolase inhibits apoptosis and promotes cell invasion and proliferation of skin cutaneous melanoma

BACKGROUND

The glycolytic enzyme, α-Enolase (ENO1), catalyzes the production of phosphoenolpyruvate from 2-phosphoglycerate, thereby enhancing glycolysis and contributing to tumor progression. In the present study, we aimed to determine the role of ENO1 in skin cutaneous melanoma (SKCM) and the potential underlying mechanism.

METHODS

The Sangerbox database was used to analyze the mRNA expression of ENO1 in SKCM. Western blotting was used to assess the levels of ENO1, c-Myc, β-catenin, MMP-9, PGAM1, and MMP-13 in SKCM-derived cell lines or tumor tissues from patients with SKCM. The pCMV-SPORT6-ENO1 and pET-28a-ENO1siRNA plasmids were used to overexpress and knockdown ENO1 in SKCM cells, respectively. To determine the function of ENO1 in the malignant behavior of SKCM cells, we performed a wound-healing assay, cell counting kit 8 assay, and transwell chamber analyses. The production of pyruvate and lactic acid in tumor cells was evaluated using their respective kits.

RESULTS

Compared with non-tumor tissues, ENO1 was found to be overexpressed in SKCM tissues. In SKCM cells, ENO1 overexpression promoted invasion, migration, and proliferation of tumor cells; increased pyruvate and lactate production; and increased β-catenin, MMP-9, MMP-13, and c-Myc levels. The opposite effects were observed in SKCM cells silenced for ENO1.

CONCLUSIONS

These results indicate that ENO1 is involved in SKCM progression by enhancing the invasion and proliferation of tumor cells. In addition, ENO1 might have an important function in tumor cell glycolysis. Therefore, ENO1 represents a potential therapeutic target for treatment of SKCM.

Tattooing in Psoriasis: A Questionnaire-Based Analysis of 150 Patients

Purpose

Among populations of Western countries, tattoos have become an accepted form of skin ornamenting. With tattoos growing in popularity, also patients suffering from chronic dermatoses may more often be willing to get tattooed. Psoriasis is not considered as a strict contraindication for tattooing; however, it is not advised to get a tattoo while undergoing immunosuppressive treatment and during an active stage of the disease. We attempted to assess the knowledge level of tattooed psoriatic patients about the potential risks connected with tattooing, as well as to explore their attitudes and tendencies towards this procedure. Moreover, we analyzed the frequency and type of tattoo complications in this study group.

Patients and Methods

An anonymous, online questionnaire was performed among online communities dedicated to psoriasis. Data from 150 tattooed psoriatic patients have been scrutinized.

Results

Eight percent of the surveyed psoriatic patients sought medical advice before getting a tattoo. While undergoing the tattooing procedure, 23 (15.3%) of the respondents received systemic psoriasis treatment: 8 (5.3%) being treated with methotrexate, 5 (3.3%) with cyclosporine A, one (0.7%) acitretin, and 9 (6%) patients were under biological treatment. Thirteen (8.7%) of the participants experienced complications associated with their tattoos, among which, the insurgence of the Koebner phenomenon on the tattoo, was the most frequent one (8 cases- 5.3%). Getting tattooed improved patients' self-esteem in 76 (50.7%) of the cases.

Conclusion

An increased level of education among patients, medical practitioners, and tattooists concerning general precautions of tattooing in psoriasis is advisable.

The impact of external factors on psoriasis

Psoriasis is one of the most common chronic inflammatory skin diseases, constituting a significant health and socioeconomic problem. Despite numerous therapeutic options, the results of treatment very often remain insufficient. It is extremely important to remember that many external factors impact the effectiveness of therapy. This article discusses the importance of emollients in therapy and the influence of infectious agents and injuries on the course of psoriasis. Understanding the above-mentioned factors in the treatment of psoriasis is critical to achieve satisfactory therapeutic effects.

The biological basis of disease recurrence in psoriasis: a historical perspective and current models

A key challenge in psoriasis therapy is the tendency for lesions to recur in previously affected anatomical locations after treatment discontinuation following lesion resolution. Available evidence supports the concept of a localized immunological ‘memory’ that persists in resolved skin after complete disappearance of visible inflammation, as well as the role of a specific subpopulation of T cells characterized by the dermotropic CCR4⁺ phenotype and forming a local memory. Increasing knowledge of the interleukin (IL)‐23/T helper 17 (Th17) cell pathway in psoriasis immunopathology is pointing away from the historical classification of psoriasis as primarily a Th1‐type disease. Research undertaken from the 1990s to the mid‐2000s provided evidence for the existence of a large population of CD8⁺ and CD4⁺ tissue‐resident memory T cells in resolved skin, which can initiate and perpetuate immune responses of psoriasis in the absence of T‐cell recruitment from the blood. Dendritic cells (DCs) are antigen‐presenting cells that contribute to psoriasis pathology via the secretion of IL‐23, the upstream regulator of Th17 cells, while plasmacytoid DCs are involved via IL‐36 signalling and type I interferon activation. Overall, the evidence discussed in this review indicates that IL‐23‐driven/IL‐17‐producing T cells play a critical role in psoriasis pathology and recurrence, making these cytokines logical therapeutic targets. The review also explains the clinical efficacy of IL‐17 and IL‐23 receptor blockers in the treatment of psoriasis.

Urologic dermatology: a comprehensive foray into the noninfectious etiologies of balanitis

Balanitis is classically defined as inflammation of the glans penis, often also encompassing the prepuce (balanoposthitis). Several investigations have found that a sizable proportion of urology clinic visits are due to balanitis or related complaints. Balanitis can have numerous complications, including severe pain, urethral stenosis, phimosis, sexual dysfunction, and if untreated, malignancy. Unfortunately, there is no recent or comprehensive review that describes the various etiologies, clinical workup, and treatments for balanitis. Herein this review, we attempt to provide the reader with a complete and updated guide to balanitis in an attempt to improve clinical outcomes.

The hair follicle-psoriasis axis: Shared regulatory mechanisms and therapeutic targets

It has long been known that there is a special affinity of psoriasis for the scalp: Here, it occurs most frequently, lesions terminate sharply in frontal skin beyond the hair line and are difficult to treat. Yet, surprisingly, scalp psoriasis only rarely causes alopecia, even though the pilosebaceous unit clearly is affected. Here, we systematically explore the peculiar, insufficiently investigated connection between psoriasis and growing (anagen) terminal scalp hair follicles (HFs), with emphasis on shared regulatory mechanism and therapeutic targets. Interestingly, several drugs and stressors that can trigger/aggravate psoriasis can inhibit hair growth (e.g. beta-blockers, chloroquine, carbamazepine, interferon-alpha, perceived stress). Instead, several anti-psoriatic agents can stimulate hair growth (e.g. cyclosporine, glucocorticoids, dithranol, UV irradiation), while skin/HF trauma (Köbner phenomenon/depilation) favours the development of psoriatic lesions and induces anagen in "quiescent" (telogen) HFs. On this basis, we propose two interconnected working models: (a) the existence of a bidirectional "hair follicle-psoriasis axis," along which keratinocytes of anagen scalp HFs secrete signals that favour the development and maintenance of psoriatic scalp lesions and respond to signals from these lesions, and (b) that anagen induction and psoriatic lesions share molecular "switch-on" mechanisms, which invite pharmacological targeting, once identified. Therefore, we advocate a novel, cross-fertilizing and integrative approach to psoriasis and hair research that systematically characterizes the "HF-psoriasis axis," focused on identification and therapeutic targeting of selected, shared signalling pathways in the future management of both, psoriasis and hair growth disorders.

Prurigo Nodularis Is Characterized by Systemic and Cutaneous T Helper 22 Immune Polarization

Prurigo nodularis (PN) is an understudied, chronic inflammatory skin disease that disproportionately affects African Americans and presents with intensely pruritic nodules of unknown etiology. To better characterize the immune dysregulation in PN, PBMCs and skin biopsies were obtained from patients with PN and healthy subjects (majority African American) matched by age, race, and sex. Flow cytometric analysis of functional T-cell response comparing patients with PN with healthy subjects identified increased γδT cells (CD3+CD4-CD8-γδTCR+) and Vδ2+ γδT enrichment. Activated T cells demonstrated uniquely increased IL-22 cytokine expression in patients with PN compared with healthy controls. CD4+ and CD8+ T cells were identified as the source of increased circulating IL-22. Consistent with these findings, RNA sequencing of lesional PN skin compared with nonlesional PN skin and biopsy site‒matched control skin demonstrated robust upregulation of T helper (Th) 22‒related genes and signaling networks implicated in impaired epidermal differentiation. Th22‒related cytokine upregulation remained significant, with stratifications by race and biopsy site. Importantly, the expression of the IL-22 receptors IL22RA1 and IL22RA2 was significantly elevated in lesional PN skin. These results indicate that both systemic and cutaneous immune responses in patients with PN are skewed toward a Th22/IL-22 profile. PN may benefit from immunomodulatory therapies directed at Th22‒mediated inflammation.

H syndrome: A review of treatment options and a hypothesis of phenotypic variability

H syndrome is a rare autosomal recessive disorder with clinical features comprising: hyperpigmentation, hypertrichosis, hearing loss, heart anomalies, low height, hypogonadism and hepatosplenomegaly. H syndrome results from loss-of-function mutations in SLC29A3 which leads to abnormal proliferation and function of histiocytes. Herein, we discuss the considerable phenotypic heterogeneity detected in a consanguineous Egyptian family comprising of four affected siblings, two of which are monozygotic twin and the possible therapeutics. The phenotypic variability may be attributed to the role of histiocytes in the tissue response to injury. Such variable expressivity of H syndrome renders the diagnosis challenging and delays the management. The different treatment approaches used for this rare entity are reviewed.

Pediatric Psoriasis: From New Insights into Pathogenesis to Updates on Treatment

Psoriasis is a chronic inflammatory systemic disease primarily affecting the skin, but which often involves considerable comorbidities as well. One-third of psoriasis cases start during childhood. In pediatric psoriasis, an association with several medical comorbidities is also indicated. Furthermore, because of its chronic nature and frequent relapses, psoriatic patients tend to require long-term treatment and experience negative impacts on their quality of life. Considering the different clinical characteristics of pediatric psoriasis, it has recently been presented that the pathogenesis of pediatric psoriasis is distinct from adult psoriasis. Treatment for pediatric psoriasis usually involves the same methods as for adults. However, most treatments in pediatric psoriasis are used off-label and research in this regard is still lacking. Targeted therapies involving newly developed biologics are also increasingly being applied to psoriasis in children. This review summarizes the clinical characteristics of pediatric psoriasis and focuses mainly on the updated concepts of pathogenesis and treatments in pediatric psoriasis. This was undertaken to widen the understanding of these relevant aspects and to provide better management of pediatric psoriasis by clinicians.

ZFP36 family members regulate the pro-inflammatory features of psoriatic dermal fibroblasts

Dermal fibroblasts are strategically positioned underneath the basal epidermis layer to support keratinocyte proliferation and extracellular matrix production. In inflammatory conditions, these fibroblasts produce cytokines and chemokines that promote the chemoattraction of immune cells into the dermis and the hyperplasia of the epidermis, two characteristic hallmarks of Psoriasis (Pso). However, how dermal fibroblasts specifically contribute to Pso development remains largely uncharacterized. Here we investigated through which cytokines and signaling pathways dermal fibroblasts contribute to the inflammatory features of psoriatic skin. We show that dermal fibroblasts from lesional Pso skin are important producers of inflammatory mediators, including IL6, CXCL8 and CXCL2. This increased cytokine production was found to be regulated by ZFP36 family members ZFP36, ZFP36L1 and ZPF36L2, RNA-binding proteins with mRNA-degrading properties. Additionally, the expression of ZFP36 family proteins was found reduced in chronic inflammatory conditions that mimic psoriatic lesional skin. Collectively, these results indicate that dermal fibroblasts are important producers of cytokines in psoriatic skin, and that reduced expression of ZFP36 members in Pso dermal fibroblasts contributes to their inflammatory phenotype.

Therapeutic Development Based on the Immunopathogenic Mechanisms of Psoriasis

Psoriasis, a complex inflammatory autoimmune skin disorder that affects 2–3% of the global population, is thought to be genetically predetermined and induced by environmental and immunological factors. In the past decades, basic and clinical studies have significantly expanded knowledge on the molecular, cellular, and immunological mechanisms underlying the pathogenesis of psoriasis. Based on these pathogenic mechanisms, the current disease model emphasizes the role of aberrant Th1 and Th17 responses. Th1 and Th17 immune responses are regulated by a complex network of different cytokines, including TNF-α, IL-17, and IL-23; signal transduction pathways downstream to the cytokine receptors; and various activated transcription factors, including NF-κB, interferon regulatory factors (IRFs), and signal transducer and activator of transcriptions (STATs). The biologics developed to specifically target the cytokines have achieved a better efficacy and safety for the systemic management of psoriasis compared with traditional treatments. Nevertheless, the current therapeutics can only alleviate the symptoms; there is still no cure for psoriasis. Therefore, the development of more effective, safe, and affordable therapeutics for psoriasis is important. In this review, we discussed the current trend of therapeutic development for psoriasis based on the recent discoveries in the immune modulation of the inflammatory response in psoriasis.

Pathergy Phenomenon

Skin pathergy reaction (SPR) is a hyperreactivity response to needle induced trauma which is characterized by a papule or pustule formation, 24-48 h after sterile-needle prick. It is affected by a wide array of factors, including the physical properties of the needles being used, number of pricks and disease related factors such as male gender, active disease. There is a great variation in reactivity among different populations with very low positivity rate in regions of low prevalence like Northern Europe, and higher prevalance mainly in communities living along the historical Silk Road, like Turkey, China and Middle Eastern countries. SPR is not constant during the disease course, has lost its sensitivity over decades and can be positive in various disorders including Sweet's syndrome, pyoderma gangrenosum, Crohn's diesease, A20 haploinsufficiency, deficiency of IL-1-receptor antagonist and few others. Nevertheless, it is a criteria included into many currently used diagnostic or classification criteria for Behçet's disease. Although, not being fully uncovered yet, available data points to the activation of both innate and adaptive immune system with an inflammatory response mediated by polymorphonuclears and T-cells. In addition to its utility in diagnosis of Behçet's Disease, SPR may serve as a model for investigating the inflammatory pathways involved in the etiopathogenesis of this complex disease.

A peristomal plaque of sudden occurrence

Koebner phenomenon regards the formation of a psoriatic lesion after a trauma, including tattoo, insect bite or other injuries. Although this manifestation is not specific for psoriasis, physicians should be aware because early recognition may be helpful in making the diagnosis when present.

Mask-induced Koebner phenomenon and its clinical phenotypes: A multicenter, real-life study focusing on 873 dermatological consultations during COVID-19 pandemics

During COVID-19 pandemic, wearing masks for prevention became mandatory but evidence suggest that is also detrimental for skin. Although facial dermatoses due to masks increase in both healthcare workers and general population, a pathogenetic hypothesis remains still elusive. We aimed to evaluate the prevalence of dermatological consultations due to Koebner triggered dermatoses In this prospective, multicenter, real life study carried out in Italy from March 11th to December 11th 2020 during COVID-19 pandemics, dermatological consultations (in-person and telemedicine) to study the prevalence of Koebner (KB) phenomenon due to masks were evaluated. Boyd and Nelder classification was adopted for Koebner phenomenon and Bizzozero's for KB intensity. A total of 229/873 (26.2%) dermatological consultations were KB triggered dermatoses and lesions were located in mask-covered ear area (76 [33.2%]), malar area (73 [31.8%]), perioral area (53 [23.1%]), and nose (27 [11.8%]). The first KB category grouped 142 patients (psoriasis, vitiligo, maskne, and mask rosacea), the second one 24 (warts, molluscum contagiosum, and impetigo), the third one 46 (atopic dermatitis), and the fourth one 17 (eczema). Among previously KB negative psoriatic patients that became KB positive, 9/13 (69.2%) had discontinued or modified the prescribed antipsoriatic treatment. Mask-related Koebner phenomenon is an important clinical sign to orient clinician's therapeutic protocols during COVID-19 pandemic, especially in patients with psoriasis.

Role of CYR61 in psoriatic lesional and perilesional skin: A clinical and immunohistochemical study

BACKGROUND

Psoriasis is considered as an immune-mediated disorder with significant epidermal hyperplasia and inflammation. Cysteine-rich angiogenic inducer 61 (CYR61), known as CCN family member 1 (CCN1), plays an important role in cell proliferation and neovascularization which may trigger psoriasis development.

AIMS

This study aimed to assess the immunostaining of CYR61 in psoriatic skin (lesional and perilesional) compared to control skin.

PATIENTS/METHODS

This is a case-control study. The Psoriasis Area and Severity Index (PASI) was used to evaluate disease severity. A punch biopsy was taken from psoriatic skin lesions (30), perilesional (30) skin, and matched site of controls (20). The pathological and immunostaining assessments of CYR61 were conducted.

RESULTS

There was a significant gradual progressive overexpression of CYR61 in keratinocytes from control skin to perilesional and lesional psoriatic skin (P = .00). Moreover, lesional psoriatic skin showed overexpression of CYR61 in inflammatory cells in the dermis than controls. CYR61 expression (lesional epidermis) revealed a significant positive correlation with the PASI score (r = .63; P = .00). There was a significant relationship between intensity and H-core of CYR61 in the lesional psoriatic epidermis with joint affection.

CONCLUSION

CYR61 may trigger epidermal hyperplasia and potentiate inflammatory infiltration in psoriasis vulgaris patients, and therapies targeting CYR61 may be effective in the management of psoriasis vulgaris.

Locus Minoris Resistentiae: Two Cases of Malignant Metastasis and Review of Literature

Locus minoris resistentiae refers to a region of decreased resistance within the body. This occurs from changes to the microenvironment secondary to previous trauma and results in increased vulnerability. As a result, infection, inflammatory processes, and malignancy may localize to this area. In this article, we describe 2 unique cases of malignancy, primary prostate carcinoma and serous carcinoma of the ovary, both of which disseminated to sites of prior trauma. We review the available literature, discuss proposed pathophysiology, and highlight the need for further investigations along with increased clinician awareness.

Koebner phenomenon induced by the use of a computer mouse in an occupational setting: case report

Occupational activities are well-known triggers for the onset or aggravation of several dermatoses. The Koebner phenomenon is characterized by the appearance of cutaneous lesions typical of a given inflammatory dermatosis in an area where the skin was injured by mechanical, chemical, or biological agents. Although it is usually easily identified when associated to significant trauma, the Koebner phenomenon may go unnoticed when a small-scale injury underlies its pathogenesis. Herein, we report a case of Koebner phenomenon induced by the repetitive use of a computer mouse in an occupational setting, leading to recalcitrant psoriatic lesions on the palm of the right hand. When atypical features or unexpected poor responses to treatment are observed in skin conditions, a complete social and occupational anamnesis is paramount to identify aggravating factors and allow successful patient management.

Topographic Differential Diagnosis of Chronic Plaque Psoriasis: Challenges and Tricks

BACKGROUND

Psoriasis is an inflammatory skin disease presenting with erythematous and desquamative plaques with sharply demarcated margins, usually localized on extensor surface areas.

OBJECTIVE

To describe the common differential diagnosis of plaque psoriasis classified according to its topography in the scalp, trunk, extremities, folds (i.e., inverse), genital, palmoplantar, nail, and erythrodermic psoriasis.

METHODS

A narrative review based on an electronic database was performed including reviews and original articles published until 1 September 2020, assessing the clinical presentations and differential diagnosis for psoriasis.

RESULTS

Several differential diagnoses could be considered with other inflammatory, infectious, and/or neoplastic disorders. Topographical differential diagnosis may include seborrheic dermatitis, tinea capitis, lichen planopilaris in the scalp; lupus erythematosus, dermatomyositis, cutaneous T-cell lymphomas, atopic dermatitis, syphilis, tinea corporis, pityriasis rubra pilaris in the trunk and arms; infectious intertrigo in the inguinal and intergluteal folds and eczema and palmoplantar keratoderma in the palms and soles.

CONCLUSIONS

Diagnosis of psoriasis is usually straightforward but may at times be difficult and challenging. Skin cultures for dermatophytes and/or skin biopsy for histological examination could be required for diagnostic confirmation of plaque psoriasis.

Antihistamines-refractory chronic pruritus in psoriatic patients undergoing biologics: aprepitant vs antihistamine double dosage, a real-world data

BACKGROUND

Psoriasis-related pruritus (PRP) in patients under systemic treatment is challenging. The risk to switch anti-psoriatic drugs and to lose response to previous therapy is high, thus dermatologists prefer to add an anti-pruritic agent.

OBJECTIVES

To evaluate the effect of anti-histamines and aprepitant in treating PPR of psoriatic patients undergoing systemic anti-psoriatic therapies.

METHODS

A pilot observational open-label study was performed on responsive psoriatic patients with PPR under treatment. Initial therapy included oral rupatadine (10 mg/day for 30 days). In case of the Epworth Sleepiness Scale (ESS) was above 14, patients were switched to aprepitant (80 mg/day for 7 days), otherwise, rupatadine dosage was increased (20 mg/day for 7 days). Clinical evaluation was performed at the baseline (T0) and after 7 days (T7).

RESULTS

We enrolled 40 patients with PPR, 20 in each group. Age, gender, Psoriatic arthritis (PsA) and the itch - VAS, were matched. At T7, aprepitant displayed higher improvements than rupatadine (itch - VAS = 4 [3-5] vs 8.5 [8-9], p < .01, DLQI = 14 [13-16] vs. 18 [16-21], p < .01 and ESS = 5 [4-7] vs 15 [14-16], p < .01). Doubling the rupatadine dosage from 10 mg to 20 mg/day only slightly improve itch (itch - VAS = 9 [8-10] vs 9 [8-9], p = .03), conversely no modifications in the quality of life (DLQI = 18 [17-20] vs 18 [17-21], p = .73) and increased sleepiness (ESS = 10 [9-11] vs 15 [14-16], p < .01).

CONCLUSIONS

Aprepitant may be a valid alternative in PPR patients with ESS >14 under antihistamines.

Mechanisms of Beta-Blocker Induced Psoriasis, and Psoriasis De Novo at the Cellular Level

Beta-blockers are a commonly prescribed medication, but the increase in use goes hand in hand with increasing side effects; one of particular interest lately has been its dermatological reactions. Although rare, beta-blockers can exacerbate pre-existing psoriasis and also cause de novo psoriasis in patients naïve to the disease. The mechanism by which this occurs is still unclear, although numerous articles have been published throughout the years as to how this unusual effect takes place. The most common mechanism suggests that beta-blockers cause intracellular changes in calcium, affecting both keratinocyte proliferation and granulocyte function via decreased cyclic adenosine monophosphate (cAMP) levels. Several inflammatory mediators are known to play a role, as well as reduced expression and desensitization of the beta-adrenergic receptor itself. We discuss these posed pathways in-depth and how each contributes to the worsening or formation of new psoriasis. With this knowledge, future physicians may be more mindful of this side effect should it occur, and why they occur, to better manage our patients on this widely used medication.

Smad7 in psoriasis vulgaris patients: A clinical and immunohistochemical study

BACKGROUND

Psoriasis is an inflammatory disease that is mostly immune-derived. It causes proliferation of skin cells, forming plaques. Psoriasis etiology is unknown. It might be multifactorial.

AIMS

This work aimed to study Smad7 expression in psoriasis vulgaris patients in comparison with normal skin.

PATIENTS/METHODS

Thirty patients with psoriasis vulgaris in comparison with 20 age- and sex-matched seemingly healthy individuals were selected. We used psoriasis area and severity index (PASI) to evaluate psoriasis severity. Skin biopsies were prepared from skin lesions (30), perilesions (30) and control (20) groups for histopathological and immunostaining evaluation of Smad7.

RESULTS

Smad7 was progressively upregulated in proliferating keratinocytes from controls (58.18 ± 30.93) to perilesional (106 ± 38.93) and lesional (156.33 ± 62.01) skin (P < .001). Also, dermal inflammatory cells showed upregulation of Smad7 expression from control skin (40 ± 28.28) to skin lesions (137.33 ± 73.86) (P < .010). Smad7 expression showed a positive significant correlation with psoriasis severity (r = .452; P < .012).

CONCLUSION

Smad7 may be involved in increased keratinocyte proliferation as well as skin inflammation in psoriasis vulgaris patients.