Topical Treatment Of Psoriasis Research Articles

Design, Synthesis, and Biological Evaluation of New Selective PDE4 Inhibitors for Topical Treatment of Psoriasis.

Psoriasis is a complex and chronic inflammatory disease. Current drugs help control the symptoms of psoriasis but make no cure, urging discovery of novel drugs. We report in this paper the discovery of new phosphodiesterase 4 (PDE4) inhibitors for treatment of psoriasis. We designed and synthesized 45 new compounds, among which 14h exhibited IC50 of 0.57 nM for PDE4D and >4100-fold selectivity over other PDE families. Compound 14h inhibited release of inflammatory cytokines of TNF-α (IC50 = 34.2 μM) and IL-6 (IC50 = 40.9 μM) in Raw264.7 cells and reduced the expression of IL-1β and IL-17A in the skin of psoriasis mice. In addition, 14h alleviated IMQ-induced psoriasis in the mouse model and reduced the erythema level, scales, and thickness of the back skin of the mice. In short, our results suggested that PDE4 inhibitor 14h is a strong candidate for the topical treatment of psoriasis.

New and old topical treatments for psoriasis

Patiens with psoriasis and mild to moderate skin disease can be treated with topical agents. This review finds that the most effective topical treatment is calcipotriol and betamethasone combination formulations. Pure topical corticosteroids continue to have a role in the treatment of psoriasis, as they are available in many strengths and formulations that facilitate ease of use. In addition, the price is often lower than for the combination formulations. Topical calcineurin inhibitors can treat facial and intertriginous psoriasis to reduce the risk of skin atrophy.

Efficient Treatment of Psoriasis Using Conditioned Media from Mesenchymal Stem Cell Spheroids Cultured to Produce Transforming Growth Factor-β1-Enriched Small-Sized Extracellular Vesicles.

Psoriasis is a common chronic inflammatory disease in which keratinocytes proliferate abnormally due to excessive immune action. Psoriasis can be associated with various comorbidities and has a significant impact on health-related quality of life. Although many systemic treatments, including biologic agents, have been developed, topical treatment remains the main option for psoriasis management. Consequently, there is an urgent need to develop topical treatments with minimal side effects and high efficacy. Mesenchymal stem cells (MSCs) exhibit excellent immune regulation, anti-inflammatory activities, and therapeutic effects, and MSC-derived extracellular vesicles (EVs) can serve as crucial mediators of functional transfer from MSCs. Therefore, this study aimed to develop a safe and easy-to-use emulsion cream for treating psoriasis using MSC conditioned media (CM) containing EVs. We developed an enhanced Wharton's jelly MSC (WJ-MSC) culture method through a three-dimensional (3D) culture containing exogenous transforming growth factor-β3. Using the 3D culture system, we obtained CM from WJ-MSCs, which yielded a higher EV production compared to that of conventional WJ-MSC culture methods, and investigated the effect of EV-enriched 3D-WJ-MSC-CM cream on psoriasis-related inflammation. Administration of the EV-enriched 3D-WJ-MSC-CM cream significantly reduced erythema, thickness, and scaling of skin lesions, alleviated imiquimod-induced psoriasiform lesions in mice, and ameliorated histopathological changes in mouse skin. The upregulated mRNA expression of inflammatory cytokines, including IL-17a, IL-22, IL-23, and IL-36, decreased in the lesions. In conclusion, we present here a new topical treatment for psoriasis using an MSC EV-enriched cream.

Betulin-NLC-hydrogel for the Treatment of Psoriasis-like Skin Inflammation: Optimization, Characterisation, and In vitro and In vivo Evaluation.

Psoriasis is a chronic inflammatory skin disorder that poses significant challenges regarding effective and targeted drug delivery. Bioactive substances like betulin have shown tremendous utility in treating these conditions; however, they pose limited utility owing to their physicochemical characteristics. Here, we aimed to develop a novel topical dosage form for treating psoriasis, utilising betulin-loaded solid lipid nanoparticles (NLCs) incorporated into a hydrogel matrix. The optimization of the formulation was meticulously conducted using a design of experiments methodology, and its diverse physicochemical attributes were thoroughly examined. Evaluating betulin's in vitro release pattern from the NLC-hydrogel demonstrated consistent and regulated drug release properties. Additionally, the formulation demonstrated improved skin penetration abilities as determined by in vitro skin permeation experiments employing Franz diffusion cells- furthermore, the therapeutic effectiveness of the betulin-NLC-hydrogel was assessed by an in vivo experiment carried out using an imiquimod-induced psoriasis-like skin inflammation model in BALB/c female mice. The NLCs exhibited a pH of 5.67±0.86, particle size of 148.16±12.66 nm, and zeta potential of -22.84±2.37 mV, ensuring stability and suitability for topical use. The gel, with a pH of 6.05±0.43 and viscosity of 17550±120 cPs, showed enhanced skin hydration and lipid restoration. Drug release studies indicated a slower release from NLCs and gel, improving skin retention. Stability tests revealed that the formulations were stable at room temperature but not at elevated temperatures. The in vitro safety profile of the formulation revealed no significant adverse effects on HaCaT cell lines. The NLC gel demonstrated significant anti-psoriatic activity, reducing inflammation and cytokine levels. The betulin-NLC-hydrogel formulation exhibited promising characteristics for the topical treatment of psoriasis, showcasing optimised drug delivery, sustained release, and notable therapeutic efficacy. The findings from this study provide a foundation for the potential clinical translation of this innovative topical dosage form for improved psoriasis management.

Lipid-Based Formulation of Baricitinib for the Topical Treatment of Psoriasis

Background: Baricitinib, commonly used for autoimmune diseases, is typically administered orally, which can lead to systemic adverse effects. A topical formulation could potentially offer localized therapeutic effects while minimizing these side effects. Objectives: This study focuses on developing a lipid-based topical formulation of baricitinib (BCT-OS) for treating psoriasis. Methods: The optimized formulation was then assessed for physical, chemical, and biopharmaceutical characterization. Furthermore, the anti-inflammatory efficacy of the formulation was tested in a model of psoriasis induced by imiquimod in mice, and its tolerance was determined by the evaluation of biomechanical skin properties and an inflammation test model induced by xylol in mice. Results: BCT-OS presented appropriate characteristics for skin administration in terms of pH, rheology, extensibility, and stability. The formulation also demonstrated a notable reduction in skin inflammation in the mouse model, and high tolerability without affecting the skin integrity. Conclusions: BCT-OS shows promise as an alternative treatment for psoriasis, offering localized therapeutic benefits with a potentially improved safety profile compared to systemic administration.

Formulation, Development & Evaluation of Mallotus philippensis Extract Loaded NLCS based Nanogel for Psoriasi.

The current study’s objective was to develop and evaluate the potential of Bergenin-loaded nanostructured lipid carriers (NLCs) as a novel topical therapeutic for psoriasis, obtained from Mallotus philippensis. NLCs loaded with Bergenin were created using a modified Hot-melt emulsification technique, and then Box-Behnken design optimization was performed. The Independent factors were concentration of solid lipid, the concentration of liquid lipid and the concentration of surfactant. Particle size, entrapment efficiency, and drug permeation percentage were the dependent variables. The Bergenin-nano-lipid carriers (NLCs) that has been optimized has a Particle size of 148 ± 0.37 nm, an %Entrapment efficiency of 93.44 ± 0.45%, and a drug permeation percentage was found to be 83.56 ± 0.137. and the zeta potential was - 0.0617 ± 5.53 mV and the polydispersity index (PDI) was 0.30 ± 0.03. Bergenin’s existence within the NLCs was verified by FTIR. The outcomes show that Nanostructured lipid carriers have the ability to deliver Bergenin for topical psoriasis treatment.

Preparation and characterisation of esculetin-loaded nanostructured lipid carriers gels for topical treatment of UV-induced psoriasis

Significance As an inflammatory and autoimmune skin condition, psoriasis affects 2–3% of people worldwide. Psoriasis requires prolonged treatments with immunosuppressive medications which have severe adverse effects. Esculetin (Esc) is a natural medication that has been utilised to treat psoriasis. Objective The goal of this work is to improve Esc’s solubility by developing novel Esc nanostructured lipid carriers (NLCs) for treating psoriasis and increasing the residence time on the skin which infers better skin absorption Methods The particle size, zeta potential and entrapment efficiency (EE) of Esc NLCs were assessed. Incorporating NLCs into gum Arabic gel preparation enhances their industrial applicability, absorption and residence time on the skin. Esc NLC gels were evaluated by in vitro release and in vivo effectiveness on a rat model of UV-induced psoriasis. Results Esc NLCs showed high EE reaching more than 95% and reasonable particle size ranging between (53.86 ± 0.38 to 236.3 ± 0.11 nm) and were spherical. The release study of Esc NLCs gel demonstrated a fast release of Esc denoting enhanced bioavailability. Compared to free Esc, Esc NLCs gel (F2) could considerably lower the level of CD34 and TNF-α in the skin. The results were validated through histopathological analysis. Conclusion As Esc NLCs gel (F2) has strong anti-inflammatory properties, our results showed that it presented a significant potential for healing psoriasis.

50584 Online Continuing Medical Education Improved Dermatologists’ Knowledge, Competence, and Confidence About New Topical Treatments for Psoriasis

50584 Online Continuing Medical Education Improved Dermatologists’ Knowledge, Competence, and Confidence About New Topical Treatments for Psoriasis

A comparison of the safety and efficacy of tapinarof and roflumilast topical therapies in the management of mild-to-moderate plaque psoriasis.

Psoriasis is an immune-mediated inflammatory skin disease. First-line topical treatments include steroids, calcineurin inhibitors, vitamin D analogs, and anthralin. Recently, novel topical therapeutics like tapinarof and roflumilast have emerged with unique anti-inflammatory mechanisms and promising efficacy profiles. This review utilized PubMed, SCOPUS, and Web of Science databases to identify recent studies on tapinarof and roflumilast. Criteria focused on efficacy, safety profiles, and therapeutic roles in psoriasis treatment. Four primary literature articles were identified for tapinarof and five for roflumilast. Both drugs demonstrated strong efficacy with minimal adverse events in treating mild-to-moderate plaque psoriasis. Tapinarof showed more frequent but mild adverse effects, while roflumilast had less frequent but more severe side effects. Tapinarof and roflumilast offer once-daily dosing and successful treatment in restricted areas, potentially enhancing patient adherence. Cost remains a limiting factor, necessitating future comparative studies to evaluate the efficacy, safety, and cost-effectiveness between the two drugs. Tapinarof and roflumilast present promising topical treatments for psoriasis, showing efficacy and manageable safety profiles. Further research is crucial to fully elucidate their comparative benefits and drawbacks in clinical practice.

Development and evaluation of methotrexate-loaded nanoemulsion formulation for topical treatment of psoriasis.

Psoriasis is a chronic inflammatory disease that is becoming widespread and is associated with many kinds of additional severe diseases. The present study aimed to develop a methotrexate-loaded almond oil-based nanoemulsion formulation (MTX NE) for topical administration. The drug-loaded nanoemulsion formulation was prepared by high shear homogenization technique. The formulation's stability, as well as other physical and chemical characteristics, including entrapment effectiveness, drug release kinetics, skin permeability, skin irritation, and in vivo evaluation of the optimized formulation, was assessed. Additionally, imiquimod-induced psoriasis in rats was employed to investigate the efficacy of MTX NE against skin disorders. The MTX NE formulation was developed with a particle size of 18.74 ± 9.748nm, a polydispersity index (PDI) of 0.198 ± 0.01, and an average entrapment efficiency of 79.65 ± 3.84%. The release kinetics model estimates 81.08% drug release at pH 5.5 after 24h. The major layers of the skin, the epidermis, and dermis were successfully fluidized by the optimized MTX NE formulation, as shown by FTIR results, most likely enhancing drug retention and permeability. However, since Tween 80 and PEG 400 are well-known penetration enhancers, their application greatly accelerates these effects. Permeation data indicate that after 24h, methotrexate was released from the nano-emulsion at 76.83 ± 4.98g/cm2 with a flux rate of 2.385 ± 0.61µg/cm2/h. The in vivo study conducted on rabbit skin showed that the enhanced skin penetration of the prepared MTX-loaded nanoemulsion formulation does not cause any structural modifications in the inter-cellular lipid layers of the stratum corneum. Rabbits used in the in vivo anti-psoriatic investigation demonstrated that MTX NE produced a 95% reduction in PASI. The pharmacokinetic profile revealed that the Cmax, Tmax, and t1/2 values were 8.63µg/mL, 12.5h, and 17.77 ± 2.21h, respectively. These findings suggest that the formulation MTX NE is effective in treating psoriasis and may reduce psoriasis symptoms.

Breakthrough Opportunities of Nanotheranostics in Psoriasis: From Pathogenesis to Management Strategy.

In this paper, we have discussed recent advances in our understanding of the aetiology of psoriasis, particularly as they relate to aryl hydrocarbon receptors in DCs, Langerhans cells, macrophages, signal transducer and activator of transcription 3 pathways, and dermal vascular endothelial cells. Here, we have shown that the ability to target specific cellular and molecular components of psoriasis pathogenesis with nanoscale precision using phos-phodiesterase 4 inhibitors represents a transformative opportunity to address the complex nature of this dermatological condition. In this review, we have examined the molecular mechanisms behind the pathogenic features of psoriasis and new treatments being tested in clinical settings. There is research being done on new treatments created in the last ten years. This field highlights the advantages of nan-otechnological technologies as cutting-edge candidates for drug delivery systems in psoriasis and other inflammatory chronic skin disorders. Future Developments: Nanotechnology-based treatments currently under study show good effi-cacy and low side effect profiles. However, long-term prospective trials are required to demon-strate long-term safety and effectiveness. Phosphodiesterase inhibitors, Janus kinase inhibitors, nonsteroidal anti-inflammatory drugs, combinations of vitamin D3 derivatives and corticoster-oids, and coal tar formulations are some of the newer topical treatments for psoriasis. The psoriasis treatment continues to involve conventional medications (i.e., medi-cines that are generally acknowledged as either normal therapy or outdated remedies), whether used topically or orally. Nonetheless, we are starting to see initiatives to create pharmaceuticals and biosimilars with better therapeutic results, fewer side effects, and greater efficacy.

Development and Optimization of Dipyridamole- and Roflumilast-Loaded Nanoemulsion and Nanoemulgel for Enhanced Skin Permeation: Formulation, Characterization, and In Vitro Assessment.

This study explores developing and optimizing a nanoemulsion (NE) system loaded with dipyridamole and roflumilast, aiming to improve skin penetration and retention. The NE formulation was further transformed into a nanoemulgel to enhance its application as a topical treatment for psoriasis. Solubility studies were conducted to select the oil, surfactant, and co-surfactant. Phase diagrams were constructed using the aqueous phase titration method. All the formulations were in nanoscale, and Formula (F2) (which contains oleic acid oil as the oil phase, a mixture of Surfactant Tween 80 and co-surfactant (ethanol) at a ratio of 1:2 in addition to distilled water as an aqueous phase in a ratio of 1:5:4, respectively) was the selected formula depending on the particle size, PDI, and zeta potential. Formula (F2) has the best ratio because it gives the smallest nanoemulsion globule size (particle size average of 167.1 nm), the best homogenicity (lowest PDI of 0.195), and the highest stability (higher zeta potential of -32.22). The selected formula was converted into a nanoemulgel by the addition of 0.5% (w/w) xanthan gum (average particle size of 172.7 nm) and the best homogenicity (lowest PDI of 0.121%) and highest stability (higher zeta potential of -28.31). In conclusion, the selected formula has accepted physical and chemical properties, which enhanced skin penetration.

Combined photodynamic therapy and hollow microneedle approach for effective non-invasive delivery of hypericin for the management of imiquimod-induced psoriasis

Background Conventional topical psoriasis treatments suffer from limited delivery to affected areas and skin irritation due to high local drug concentration. Purpose This study aims to prepare hypericin (HYP) loaded nanostructured lipid carriers (NLCs) and their application in psoriasis treatment through intradermal administration using hollow microneedles assisted by photodynamic therapy. Methods The colloidal characteristics of NLCs, entrapment efficiency and morphology were evaluated. An ex-vivo skin distribution study was conducted along with testing the in vivo antipsoriatic activity in mice with the imiquimod-induced psoriasis model. Results The particle size and zeta potential of HYP-NLCs were 167.70 nm and −18.1, respectively. The ex-vivo skin distribution study demonstrated the superior distribution of HYP-NLCs to a depth of 1480 µm within the skin layers relative to only 750 µm for free HYP. In vivo studies revealed that the levels of NF-KB, IL 6, MMP1, GSH, and catalase in the group treated with HYP-NLCs in the presence of light were comparable to the negative control. Conclusions The histopathological inspection of dissected skin samples reflected the superiority of HYP-NLCs over HYP ointment. This could be ascribed to the effect of nanoencapsulation on improving HYP properties besides the ability of hollow microneedles to ensure effective HYP delivery to the affected psoriatic area.

Transethosomal Carrier of Curcumin for Improved Topical Delivery: Optimization, In-vitro and Stability Assessment

Objective:: Currently, there is a clear lack of effective topical treatments for psoriasis. In light of this unaddressed requirement, the work intends to develop, enhance, and assess the effectiveness of a curcumin transethosomal gel for managing psoriasis. This work signifies the delivery of a potential solution to fill the gap in topical psoriasis treatment. Material and Methods:: Curcumin-loaded transethosomes were prepared using a mechanical dispersion method. An initial study was conducted to determine the ideal concentrations of Lipoid S100 and Isopropyl Myristate (IPM). To refine the ultimate transethosomal formulation, a full factorial design (32) was employed, incorporating different levels of Lipoid S100 and IPM. Drug release investigations and pharmacokinetics assessments of curcumin concentrations were performed using a specialized dissolution apparatus and an animal model, respectively. Results:: The characterization profile and analytical examinations have affirmed the stability of the formulation throughout the study duration. Our findings indicate that the drug release mechanism conforms to a diffusion pattern akin to Fickian transport. Furthermore, In-vivo investigations revealed that the curcumin concentration in the bloodstream after oral administration was significantly superior to that of the conventional formulation. Conclusion:: Using curcumin-loaded transethosomes extends drug contact time and facilitates controlled drug release, leading to enhanced bioavailability, decreased dosage needs, and heightened patient safety.

Fabrication and characterization of apremilast-loaded zinc oxide-mesoporous silica nanoparticles for psoriasis treatment.

Aim: The study was aimed to formulate and evaluate apremilast-loaded zinc oxide-mesoporous silica nanoparticles for treatment of psoriasis. Materials & methods: Mesoporous silica nanoparticles were prepared by using sol-gel method and evaluated for particle size, in vitro drug release, in vitro cytotoxicity study and in vivo pharmacodynamic study. Results: The synthesized mesoporous silica nanoparticles showed particle size of 319.9±3.9nm, with 24±0.217% of loading capacity. In vitro cytotoxicity study on A-431 cell line showed increased anti-psoriatic activity of apremilast-loaded zinc oxide-mesoporous silica nanoparticles. In vivo pharmacodynamic study and histological studies showed improved efficacy of drug in imiquimod-induced psoriasis mice model. Conclusion: The apremilast-loaded zinc oxide-mesoporous silica nanoparticles showed improved therapeutic efficacy, suggesting that they are promising approach for topical treatment of psoriasis.

Innovative Topical Therapy for Otic Eczema

An innovative topical treatment for psoriasis and atopic dermatitis has recently received patent approval from the Spanish Ministry of Industry, Trade, and Tourism. This topical treatment Psorisbye, presented in the form of a lotion, includes a combination of clobetasol, papaverine hydrochloride, spironolactone, a milk-peptide complex, and propylene glycol. A 56-year-old female presented to our outpatient clinic with bilateral otic eczema. The patient had no significant past medical history and primarily complained of intense pruritus in the lesions. The patient was advised to use our recently patented lotion, Psorisbye, once daily for 7 days. Two days after beginning the treatment, the patient experienced significant relief from itching sensations. By the 8th day, during an examination at the outpatient clinic, a notable improvement in the scaled lesions was observed. While the preliminary results exhibited by Psorisbye in the context of this specific case are indeed promising, the imperative to establish its efficacy and reliability necessitates the initiation of further investigations characterized by more expansive sample sizes and prolonged follow-up periods.

Calcipotriol Nanosuspension-Loaded Trilayer Dissolving Microneedle Patches for the Treatment of Psoriasis: In Vitro Delivery and In Vivo Antipsoriatic Activity Studies.

Psoriasis, affecting 2-3% of the global population, is a chronic inflammatory skin condition without a definitive cure. Current treatments focus on managing symptoms. Recognizing the need for innovative drug delivery methods to enhance patient adherence, this study explores a new approach using calcipotriol monohydrate (CPM), a primary topical treatment for psoriasis. Despite its effectiveness, CPM's therapeutic potential is often limited by factors like the greasiness of topical applications, poor skin permeability, low skin retention, and lack of controlled delivery. To overcome these challenges, the study introduces CPM in the form of nanosuspensions (NSs), characterized by an average particle size of 211 ± 2 nm. These CPM NSs are then incorporated into a trilayer dissolving microneedle patch (MAP) made from poly(vinylpyrrolidone) and w poly(vinyl alcohol) as needle arrays and prefrom 3D printed polylactic acid backing layer. This MAP features rapidly dissolving tips and exhibits good mechanical properties and insertion capability with delivery efficiency compared to the conventional Daivonex ointment. The effectiveness of this novel MAP was tested on Sprague-Dawley rats with imiquimod-induced psoriasis, demonstrating efficacy comparable to the marketed ointment. This innovative trilayer dissolving MAP represents a promising new local delivery system for calcipotriol, potentially revolutionizing psoriasis treatment by enhancing drug delivery and patient compliance.

Activity of hydrogel-vitamin D3 /bacterioruberin nanoparticles on imiquimod-induced fibroblasts-keratinocytes spheroids

Topical administration of vitamin D3 (VD3) analogs and corticosteroids is the mainstay treatment for mild localized psoriasis. VD3 however is an unstable class II drug (insoluble and permeable), classically formulated as unattractive viscous and oil-based ointments or creams. In this work, nanostructured archaeolipid carriers (NAC) with a core loaded with VD3 and the C50 dipolar carotenoid from halophilic archaea bacterioruberin (BR): NAC-VD3, were formulated into a carbopol hydrogel: gNAC-VD3. After its rheological characterization, its anti-inflammatory and antioxidant activity was assessed on bi-cellular spheroids, consisting of a core of fibroblasts surrounded by a ring of keratinocytes activated with imiquimod (IMQ) as a psoriasis model. gNAC-VD3 (0.8 mg VD3/135 μg BR/gram gel) conserved the antioxidant activity, showed pseudoplastic non-Newtonian behaviour, stability over time, good occlusion capacity and spreadability, all suitable properties for topical application in patients with psoriasis. gNAC-VD3 did not decrease the viability of spheroids but significantly reduced the release of proinflammatory cytokines (IL-8, IL-6, TNF-α), oxidative stress (ROS), and matrix metalloproteinases from IMQ-induced spheroids to levels similar to the uninduced spheroids. Results suggest that gNAC-VD3 may constitute a potential anti-inflammatory agent for the topical treatment of mild psoriasis and deserves further in vivo exploration.

Development of a film-forming oleogel with increased substantivity for the treatment of psoriasis

The aim of this work was the development of a film-forming formulation (FFF) for the topical treatment of psoriasis that shows an increased substantivity compared to conventional semi-solid dosage forms. The developed formulation is an oleogel. It is based on a combination of castor oil and medium chain triglycerides, and the oil-soluble film former MP-30 (Croda GmbH, Nettetal, Germany), a polyamide that upon mixing with a polar oil entraps the oil und thus substantially increases the viscosity of the formulation up to a semisolid state. Betamethasone dipropionate (BDP) and calcipotriole (CA) were used as active pharmaceutical ingredients (APIs). Oleogels of different compositions were evaluated regarding substantivity, rheological properties, ex-vivo penetration into the skin and ex-vivo permeation through the skin. Marketed products were used as controls. It was found that the amount of betamethasone dipropionate penetrating and permeating into and through the skin from the film-forming formulation is at an intermediate value compared to the marketed products. The substantivity of the developed formulation is described by an amount of 57.7 % formulation that remains on the skin surface and is thus significantly higher compared to the marketed products. In the film forming formulation, the proportion of API penetrating the skin remains the same when the skin repetitively brought in contact with a piece of textile during the penetration experiment. In contrast with the in-market formulations tested, this proportion was reduced by up to 97 %. As a result, the developed formulations can lead to an increased patient compliance.

An update on topical therapies for psoriasis.

Topical therapies are a mainstay of treatment for mild psoriasis and may be a useful adjunct in treatment of moderate-to-severe psoriasis. This review summarizes recent advances in topical therapies for psoriasis and currently available treatments. Topical aryl hydrocarbon receptor modulators (tapinarof) and topical phosphodiesterase-4 inhibitors (roflumilast) have been proven effective in randomized controlled trials for psoriasis. Although topical JAK inhibitors have also been studied, none are currently licensed for treatment of psoriasis. Topical corticosteroids and vitamin D analogues remain the most commonly used and widely available topical treatments for psoriasis. Cost may limit use of novel topical agents. Although the novel topical agents tapinarof and roflumilast are licensed for treatment of psoriasis by the FDA in the United States, they have not yet been licensed in Europe, and it remains to be seen whether they will be limited by cost.