A narrative review of psoriasis and multiple sclerosis: links and risks

Reevaluating the role of interferon-beta in psoriasis pathogenesis: A registry-based self-controlled study

Interferon-beta has been suggested as a trigger of psoriasis, yet a systematic investigation is lacking. This study aimed to assess the risk of developing psoriasis following interferon-beta treatment, utilizing a pharmaco-epidemiological approach to investigate the role of interferon-beta in psoriasis pathogenesis. We included all treatment-naïve patients with multiple sclerosis (MS) in Denmark who initiated interferon-beta treatment for MS from January 1996 to June 2023. These patients were compared to a control cohort of patients with MS treated with other disease-modifying drugs. We compared the incidence rates of psoriasis before and during the treatment. Data for this study were extracted from the Danish MS Registry and integrated with information from other national Danish health registries. Among 7174 patients treated with interferon-beta, the incidence rate of psoriasis post-treatment initiation was slightly higher (2.01 per 1000 person-years) compared to the rate prior to treatment (1.67 per 1000 person-years). This increase did not achieve statistical significance (P = 0.53), with an incidence rate ratio (IRR) of 1.20 (95% confidence interval [CI] 0.68-2.13). The control cohort showed an increase in psoriasis incidence post-treatment initiation (3.12 per 1000 person-years) compared to prior (1.11 per 1000 person-years), with an IRR of 2.80 (95% CI 1.36-4.77, P = 0.0038). This registry-based self-controlled study does not support the theory that interferon-beta acts as a trigger for psoriasis development.

Clinical implications for the association of psoriasis and multiple sclerosis: an observational study

BACKGROUND

Multiple sclerosis (MS) and psoriasis (PsO) are distinct chronic autoimmune conditions with varying impacts on patients' lives. While the co-occurrence of MS and PsO has been reported, the underlying pathogenic link remains unclear. This study aimed to investigate the prevalence of PsO in a MS outpatient clinic population and explore the potential interplay between these conditions.

METHODS

316 MS patients who had at least one visit at our MS center in the last year, were selected from our outpatient MS Clinic electronic database and were e-mailed in August 2023 and inquired about a previous diagnosis of PsO. Demographic and MS history data were retrospectively gathered for two groups: MS patients without and with PsO. Information about MS phenotype, Expanded Disability Status Scale (EDSS) score at the diagnosis and at last follow-up, disease modifying therapy (DMT) were collected retrospectively from our MS data set. PsO diagnosis was confirmed by an experienced dermatologist and severity was assessed with the Psoriasis Area and Severity Index (PASI).

RESULTS

Among 253 respondents, 5.85% reported a PsO diagnosis that was confirmed after the dermatological evaluation Among patients with psoriasis 66.67% had progressive course of MS (p = 0.032) and the onset of PsO typically occurred after MS diagnosis. 9 out 15 patients had a PASI score of 0 and 6 are currently undergoing treatment with an anti-CD20 therapy. Notably, a subset of our patients were on anti-CD20 therapy and did not experience a worsening of dermatological symptoms.

DISCUSSION AND CONCLUSION

The prevalence of PsO in our outpatient MS population aligns with previous studies. Treatment approaches should be tailored to individual patient needs, emphasizing collaboration between neurologists and dermatologists. Medications like dimethyl fumarate, effective in both conditions, could be considered. The data from our study also suggest that anti-CD20 therapy may be a viable option for some patients with concurrent MS and mild PsO, without a significant worsening of dermatological symptoms. Further research is needed to elucidate the complex relationship between MS and PsO and to develop more effective therapeutic strategies for patients with both conditions.

Reverse causation between multiple sclerosis and psoriasis: a genetic correlation and Mendelian randomization study

Observational studies have found a potential bidirectional positive association between multiple sclerosis and psoriasis, but these studies are susceptible to confounding factors. We examined the directionality of causation using Mendelian randomization and estimated the genetic correlation using the linkage disequilibrium score. We performed Mendelian randomization analysis using large-scale genome-wide association studies datasets from the International Multiple Sclerosis Genetics Consortium (IMSGC, 115,803 individuals of European ancestry) and FinnGen (252,323 individuals of European ancestry). We selected several Mendelian randomization methods including causal analysis using summary effect (CAUSE), inverse variance-weighted (IVW), and pleiotropy-robust methods. According to CAUSE and IVW the genetic liability to MS reduces the risk of psoriasis (CAUSE odds ratio [OR] 0.93, p = 0.045; IVW OR 0.93, p = 2.51 × 10-20), and vice versa (CAUSE OR 0.72, p = 0.001; IVW OR 0.71, p = 4.80 × 10-26). Pleiotropy-robust methods show the same results, with all p-values < 0.05. The linkage disequilibrium score showed no genetic correlation between psoriasis and MS (rg =  - 0.071, p = 0.2852). In summary, there is genetic evidence that MS reduces the risk of psoriasis, and vice versa.

Choosing the right biologic treatment for moderate-to-severe plaque psoriasis: the impact of comorbidities

INTRODUCTION

Psoriasis is a chronic inflammatory skin disease often associated with several comorbidities, such as psoriatic arthritis, inflammatory bowel disease, obesity, diabetes mellitus or cardiovascular diseases, infections, or cancer, among others. With the progressive aging of the population, a growing number of patients with psoriasis can be expected to present multiple comorbidities. Currently, there is a wide range of biological treatments available for moderate to severe psoriasis, including tumor necrosis alpha (TNF) inhibitors, IL12/23 inhibitor, IL17 inhibitors, and IL23 inhibitors.

AREAS COVERED

This review aims to describe the specific characteristics of these drugs in relation to psoriasis comorbidities, in order to facilitate decision-making in clinical practice.

EXPERT OPINION

Some of the biological treatments can influence comorbidities, in some cases even improving them. Therefore, comorbidities are a key factor when deciding on one biological treatment over another. The development of new drugs is expanding the therapeutic arsenal for psoriasis. A high level of expertise in the field with a detailed knowledge of the characteristics of every drug is imperative to provide personalized medicine.

Thyroid hormone dysfunction in MOGAD and other demyelinating diseases

BACKGROUND

Thyroid hormones play a critical role in both neuronal and glial cell functions. Multiple sclerosis (MS) has increased co-occurrence with autoimmune thyroid diseases, and recent studies have suggested a potential link between neuromyelitis optica spectrum disorder (NMOSD) and thyroid hormones. However, no previous studies have examined the relationship between thyroid hormones and myelin oligodendrocyte glycoprotein-associated demyelination (MOGAD).

METHODS

We investigated the role of thyroid hormones in central nervous system (CNS) autoimmune demyelinating diseases in 26 MOGAD patients, 52 NMOSD patients, 167 patients with MS, and 16 patients with other noninflammatory neurological disorders. Thyroid hormone levels and clinical data (Expanded Disability Status Scale [EDSS]) were analyzed. Volumetric brain information was determined in brain magnetic resonance imaging (MRI) using the MDbrain platform.

RESULTS

MOGAD patients had significantly higher levels of free triiodothyronine (FT3) compared to NMOSD patients. No correlation was found between FT3 levels and disease severity or brain volume. Thyroid-stimulating hormone (TSH) levels did not differ significantly between the groups, but in NMOSD patients, higher TSH levels were associated with lower disability scores and increased brain volume. No significant differences in free thyroxine (FT4) levels were observed between the different groups, however, FT4 levels were significantly higher in relapsing versus monophasic MOGAD patients and increased FT4 levels were associated with a higher EDSS and lower brain volume in NMOSD patients.

CONCLUSION

Our findings highlight the potential involvement of thyroid hormones specifically in MOGAD patients and other demyelinating CNS disorders. Understanding the role of thyroid hormones in relapsing vs monophasic MOGAD patients and in comparison to other demyelinating disorder could lead to the development of therapeutic interventions. Further studies are needed to explore the precise mechanisms and potential interventions targeting the thyroid axis as a treatment strategy.

Teriflunomide-Induced Palmoplantar Pustular Psoriasis: Case Report and Review of the Literature

Teriflunomide is a once-daily oral immunomodulatory disease-modifying treatment for multiple sclerosis (MS). Skin reactions are an infrequent side effect of teriflunomide. Here, we present the case of a 52-year-old female patient with ankylosing spondylitis who was consulted for demyelinating lesions and limb weakness. She was diagnosed with multiple sclerosis and started treatment with teriflunomide. Palmoplantar pustular psoriasis developed after three weeks of treatment initiation. It is a rare side effect related to teriflunomide.

Multiple Sclerosis and Autoimmune Comorbidities

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system characterized by broad inter- and intraindividual heterogeneity and different prognoses. Multisystem comorbidities are frequent features in people with MS (PwMS) and can affect treatment choices, quality of life, disability and mortality. In this scenario, autoimmune comorbidities play a cardinal role for several reasons, such as the implication on MS pathogenesis, diagnostic delay, disease activity, disability progression, brain atrophy, and treatment choice. However, the impact of an autoimmune comorbid condition on MS is not fully elucidated. This review aims to summarize the currently available data on the incidence and prevalence of autoimmune diseases in PwMS, the possible effect of this association on clinical and neuroradiological MS course and its impact on treatment choice.

Disproportional increase in psoriasis reports in association with B cell depleting therapies in patients with multiple sclerosis

BACKGROUND

Some pathways involved in the pathogenesis of psoriasis share similarities with processes involved in multiple sclerosis (MS) pathogenesis. However, the association between MS and psoriasis is poorly understood. Since disease-modifying therapies for MS have various targets, it may be possible that the occurrence of psoriasis varies by drug.

OBJECTIVE

To analyze the frequency of psoriasis reports in patients treated with various disease-modifying therapies for MS.

METHODS

Data was collected using the FDA Adverse Event Reporting System (FAERS) and OpenFDA database between January 2009 and June 2020. The study analyzed total reports of psoriasis out of total reports in the "Skin and Subcutaneous Tissue Disorders" category for each drug and explored age, sex distribution, and report source. OpenFDA data was used to perform statistical analyses including reporting odds ratios (ROR) and information components.

RESULTS

The study identified 517 psoriasis reports of 45,547 total skin and subcutaneous tissue disorders (1.13%) in FAERS. The highest proportions of reports in this study were associated with rituximab, ocrelizumab, and interferon beta 1a. The lowest proportion of reports were associated with glatiramer acetate, alemtuzumab, dimethyl fumarate and teriflunomide. Reports of other autoimmune skin disorders were minimal (29 vitiligo, 33 pemphigoid, and 7 pemphigus). Patients primarily drove reports for most DMTs versus healthcare providers. The proportion of reports from female patients were the highest for each DMT except alemtuzumab. OpenFDA query retrieved 302 total reports of psoriasis. Significantly increased reporting odds ratios (RORs, 95% confidence interval) of psoriasis were noted for rituximab (7.14, 3.92-13.00), ocrelizumab (3.79, 2.74-5.23), and fingolimod (1.33, 1.01-1.76). Significantly decreased RORs were noted for natalizumab (0.53, 0.36-0.80), glatiramer acetate (0.58, 0.35-0.96), and dimethyl fumarate (0.71, 0.53-0.94).

CONCLUSION

There are frequent reports of psoriasis in MS patients treated with various DMTs. However, reports and RORs were disproportionally high in association with B cell depleting therapies. Further research is required to determine if certain DMTs may serve as better options for individuals affected by, or at high-risk for developing psoriasis.

Cannabis-Based Products for the Treatment of Skin Inflammatory Diseases: A Timely Review

The use of natural products in dermatology is increasingly being pursued due to sustainability and ecological issues, and as a possible way to improve the therapeutic outcome of chronic skin diseases, relieving the burden for both patients and healthcare systems. The legalization of cannabis by a growing number of countries has opened the way for researching the use of cannabinoids in therapeutic topical formulations. Cannabinoids are a diverse class of pharmacologically active compounds produced by Cannabis sativa (phytocannabinoids) and similar molecules (endocannabinoids, synthetic cannabinoids). Humans possess an endocannabinoid system involved in the regulation of several physiological processes, which includes naturally-produced endocannabinoids, and proteins involved in their transport, synthesis and degradation. The modulation of the endocannabinoid system is a promising therapeutic target for multiple diseases, including vascular, mental and neurodegenerative disorders. However, due to the complex nature of this system and its crosstalk with other biological systems, the development of novel target drugs is an ongoing challenging task. The discovery of a skin endocannabinoid system and its role in maintaining skin homeostasis, alongside the anti-inflammatory actions of cannabinoids, has raised interest in their use for the treatment of skin inflammatory diseases, which is the focus of this review. Oral treatments are only effective at high doses, having considerable adverse effects; thus, research into plant-based or synthetic cannabinoids that can be incorporated into high-quality, safe topical products for the treatment of inflammatory skin conditions is timely. Previous studies revealed that such products are usually well tolerated and showed promising results for example in the treatment of atopic dermatitis, psoriasis, and contact dermatitis. However, further controlled human clinical trials are needed to fully unravel the potential of these compounds, and the possible side effects associated with their topical use.

Neurological Complications of Biological Treatment of Psoriasis

In the available literature, little attention has been paid to the assessment of psoriasis and the biological therapy used for it and the nervous system. The purpose of this article is to discuss the relationship between psoriasis and the nervous system as well as to analyze the mechanisms that lead to neurological complications during anticytokine therapies in psoriasis. However, this connection requires further analysis. The use of biological drugs in psoriasis, although it yields positive therapeutic results, is not without numerous side effects. Serious neurological side effects of the therapy are most often visible with the use of anti-TNF-alpha, which is why patients should be monitored for their potential occurrence. Early detection of complications and rapid discontinuation of treatment with the drug may potentially increase the patient’s chances of a full recovery or improvement of his/her neurological condition. It also seems reasonable that, in the case of complications occurring during anti-TNF-alpha therapy, some of the drugs from other groups should be included in the therapy.

Biologic Treatment Algorithms for Moderate-to-Severe Psoriasis with Comorbid Conditions and Special Populations: A Review

The emergence of data from clinical trials of biologics, the approval of new biologics, and our improved understanding of psoriasis pathogenesis have increased the therapeutic possibilities for the treatment of moderate-to-severe psoriasis. Biologics currently approved for the treatment of psoriasis include tumor necrosis factor inhibitors, interleukin (IL)-17 inhibitors, ustekinumab (an IL-12/23 inhibitor), and IL-23 inhibitors. Data from clinical trials and studies of the safety and efficacy of biologics provide essential information for the personalization of patient care. We discuss the benefits and disadvantages of biologics as a first-line treatment choice, update treatment recommendations according to current evidence, and propose psoriasis treatment algorithms. Our discussion includes the following comorbid conditions: psoriatic arthritis, multiple sclerosis, congestive heart failure, inflammatory bowel disease, hepatitis B, nonmelanoma skin cancer, lymphoma, and latent tuberculosis. We make evidence-based treatment recommendations for special populations, including pediatric patients, patients with coronavirus 2019 (COVID-19), and pregnant and breastfeeding patients with psoriasis. Ultimately, individualized recommendations that consider patient preferences, disease severity, comorbid conditions, and additional risk factors should be offered to patients and updated as new trial data emerges.

The Role of Non-Selective TNF Inhibitors in Demyelinating Events

The use of non-selective tumor necrosis factor (TNF) inhibitors is well known in the treatment of inflammatory diseases such as rheumatoid arthritis, Crohn’s disease, and psoriasis. Its use in neurological disorders is limited however, due to rare adverse events of demyelination, even in patients without preceding demyelinating disease. We review here the molecular and cellular aspects of this neuroinflammatory process in light of a case of severe monophasic demyelination caused by treatment with infliximab. Focusing on the role of TNF, we review the links between CNS inflammation, demyelination, and neurodegenerative changes leading to permanent neurological deficits in a young woman, and we discuss the growing evidence for selective soluble TNF inhibitors as a new treatment approach in inflammatory and neurological diseases.

Practical recommendations for systemic treatment in psoriasis in case of coexisting inflammatory, neurologic, infectious or malignant disorders (BETA-PSO: Belgian Evidence-based Treatment Advice in Psoriasis; part 2)

Background

Psoriasis patients carry an increased risk for associated comorbidities. Dermatologists have to be aware of the effects of systemic treatments not only on psoriasis but also on co‐occurring diseases. In case of other coexisting inflammatory diseases, the right psoriasis treatment may improve both disorders. For infectious and malignant disorders, some treatments have to be avoided as they may be harmful.

Objective

The primary objective of this project was to collect evidence for the creation of practice guidelines for systemic treatment of psoriasis (BETA‐PSO: Belgian Evidence‐based Treatment Advice in Psoriasis).

Methods

Evidence‐based recommendations were formulated using a quasi‐Delphi methodology after a systematic search of the literature and a consensus procedure involving eight psoriasis experts.

Results

Recommendations are given on the use of systemic treatment in psoriatic arthritis, inflammatory bowel disease, demyelinating disorders, hepatitis B and C, HIV and cancer.

Conclusion

This expert opinion is a practical guide for dermatologists when handling psoriasis patients with these specific conditions.

Cannabinoids in the Pathophysiology of Skin Inflammation

Cannabinoids are increasingly-used substances in the treatment of chronic pain, some neuropsychiatric disorders and more recently, skin disorders with an inflammatory component. However, various studies cite conflicting results concerning the cellular mechanisms involved, while others suggest that cannabinoids may even exert pro-inflammatory behaviors. This paper aims to detail and clarify the complex workings of cannabinoids in the molecular setting of the main dermatological inflammatory diseases, and their interactions with other substances with emerging applications in the treatment of these conditions. Also, the potential role of cannabinoids as antitumoral drugs is explored in relation to the inflammatory component of skin cancer. In vivo and in vitro studies that employed either phyto-, endo-, or synthetic cannabinoids were considered in this paper. Cannabinoids are regarded with growing interest as eligible drugs in the treatment of skin inflammatory conditions, with potential anticancer effects, and the readiness in monitoring of effects and the facility of topical application may contribute to the growing support of the use of these substances. Despite the promising early results, further controlled human studies are required to establish the definitive role of these products in the pathophysiology of skin inflammation and their usefulness in the clinical setting.