Dupilumab Treatment for Generalized Prurigo Nodularis

Prurigo Nodularis: Pathogenesis and the Horizon of Potential Therapeutics

Chronic pruritus that lasts for over 6 weeks can present in various forms, like papules, nodules, and plaque types, with prurigo nodularis (PN) being the most prevalent. The pathogenesis of PN involves the dysregulation of immune cell-neural circuits and is associated with peripheral neuropathies, possibly due to chronic scratching. PN is a persistent and challenging condition, involving complex interactions among the skin, immune system, and nervous system. Lesional skin in PN exhibits the infiltration of diverse immune cells like T cells, eosinophils, macrophages, and mast cells, leading to the release of inflammatory cytokines and itch-inducing substances. Activated sensory nerve fibers aggravate pruritus by releasing neurotransmitters, perpetuating a vicious cycle of itching and scratching. Traditional treatments often fail, but recent advancements in understanding the inflammatory and itch transmission mechanisms of PN have paved the way for innovative therapeutic approaches, which are explored in this review.

A critical review of dupilumab for adult patients with prurigo nodularis

INTRODUCTION

Prurigo nodularis (PN) is a chronic inflammatory skin condition that presents with pruritus and hyperkeratotic nodules. These symptoms impact patients' quality of life and mental health. Treating prurigo nodularis is challenging, and many of the available topical and systemic therapies have limited efficacy and a myriad of adverse effects.

AREAS COVERED

In this article, we discuss the use of dupilumab for adult patients with prurigo nodularis. Dupilumab is a biologic that inhibits Th2-mediated inflammation and has been successfully used to treat a variety of dermatologic disorders. Dupilumab has revolutionized the management of PN, with recent clinical trials showing its efficacy in treating both pruritus and prurigo nodules, as well as improving quality of life. It has a favorable safety profile and is well tolerated. Other novel treatments are also currently under investigation for the treatment of PN, with early studies reporting promising results.

EXPERT OPINION

Dupilumab is becoming the drug of choice for the treatment of PN and may also be effective in treating patients with systemic underlying causes of their PN, although more studies are needed to assess this. Trials evaluating the long-term efficacy and durability of dupilumab in PN are also of interest.

Single-cell profiling of prurigo nodularis demonstrates immune-stromal crosstalk driving profibrotic responses and reversal with nemolizumab

BACKGROUND

Prurigo nodularis (PN) is a chronic neuroimmune skin disease characterized by bilaterally distributed pruritic hyperkeratotic nodules on extremities and trunk. Neuroimmune dysregulation and chronic scratching are believed to both induce and maintain the characteristic lesions.

OBJECTIVES

This study sought to provide a comprehensive view of the molecular pathogenesis of PN at the single-cell level to identify and outline key pathologic processes and the cell types involved. Features that distinguish PN skin from the skin of patients with atopic dermatitis were of particular interest. We further aimed to determine the impact of the IL31RA antagonist, nemolizumab, and its specificity at the single-cell level.

METHODS

Single-cell RNA-sequencing of skin from 15 healthy donors and nonlesional and lesional skin from 6 patients each with PN and atopic dermatitis, combined with spatial-sequencing using the 10x Visium platform. Integration with bulk RNA-sequencing data from patients treated with nemolizumab.

RESULTS

This study demonstrates that PN is an inflammatory skin disease characterized by both keratinocyte proliferation and activation of profibrotic responses. This study also demonstrates that the COL11A1+ fibroblast subset is a major contributor to fibrosis and is predominantly found in the papillary dermis of PN skin. Activation of fibrotic responses is the main distinguishing feature between PN and atopic dermatitis skin. This study further shows the broad effect of nemolizumab on PN cell types, with a prominent effect driving COL11A1+ fibroblast and keratinocyte responses toward normal.

CONCLUSIONS

This study provides a high-resolution characterization of the cell types and cellular processes activated in PN skin, establishing PN as a chronic fibrotic inflammatory skin disease. It further demonstrates the broad effect of nemolizumab on pathological processes in PN skin.

An IL-4 signalling axis in bone marrow drives pro-tumorigenic myelopoiesis

Myeloid cells are known to suppress antitumour immunity1. However, the molecular drivers of immunosuppressive myeloid cell states are not well defined. Here we used single-cell RNA sequencing of human and mouse non-small cell lung cancer (NSCLC) lesions, and found that in both species the type 2 cytokine interleukin-4 (IL-4) was predicted to be the primary driver of the tumour-infiltrating monocyte-derived macrophage phenotype. Using a panel of conditional knockout mice, we found that only deletion of the IL-4 receptor IL-4Rα in early myeloid progenitors in bone marrow reduced tumour burden, whereas deletion of IL-4Rα in downstream mature myeloid cells had no effect. Mechanistically, IL-4 derived from bone marrow basophils and eosinophils acted on granulocyte-monocyte progenitors to transcriptionally programme the development of immunosuppressive tumour-promoting myeloid cells. Consequentially, depletion of basophils profoundly reduced tumour burden and normalized myelopoiesis. We subsequently initiated a clinical trial of the IL-4Rα blocking antibody dupilumab2-5 given in conjunction with PD-1/PD-L1 checkpoint blockade in patients with relapsed or refractory NSCLC who had progressed on PD-1/PD-L1 blockade alone (ClinicalTrials.gov identifier NCT05013450 ). Dupilumab supplementation reduced circulating monocytes, expanded tumour-infiltrating CD8 T cells, and in one out of six patients, drove a near-complete clinical response two months after treatment. Our study defines a central role for IL-4 in controlling immunosuppressive myelopoiesis in cancer, identifies a novel combination therapy for immune checkpoint blockade in humans, and highlights cancer as a systemic malady that requires therapeutic strategies beyond the primary disease site.

Effectiveness of Dupilumab for Chronic Prurigo in Chinese Patients: A Real-World Case Series Study

BACKGROUND

Treatment of chronic prurigo (CPG) is challenging. As an antagonist of IL-4R, dupilumab has shown effectiveness in treating CPG in several clinical studies. Recently, the US Food and Drug Administration (FDA) approved dupilumab for the treatment of prurigo nodularis (PN).

OBJECTIVES

The purpose of this study was to examine the efficacy of dupilumab in Chinese patients with CPG, and to analyze the difference in response between subtypes of CPG.

METHODS

This retrospective study included 18 patients with CPG who were treated with dupilumab for at least 16 weeks from March 2022 to October 2022. Disease severity and patient self-assessment questionnaires were assessed at baseline and each visit, including the peak Pruritus Visual Analogue Scale (PP-VAS), Prurigo Activity and Severity Score (PAS), Investigator Global Assessment (IGA), Dermatology Life Quality Index (DLQI), Hospital Anxiety and Depression Scale (HADS) and Itchy-specific Quality of Life questionnaire (ItchyQoL).

RESULTS

After 2 weeks of dupilumab treatment, pruritus scores were significantly reduced as measured by PP-VAS scores. Prurigo Activity and Severity scores decreased significantly at Week 2, whereas IGA improved significantly at Week 8. The DLQI, HADS, and ItchyQoL scores at Week 16 also showed significant improvement from baseline. Patients in all subtypes showed improvement in pruritus and lesion severity.

CONCLUSIONS

Dupilumab was effective in improving pruritus and lesions in patients with various subtypes of CPG.

Dupilumab in Inflammatory Skin Diseases: A Systematic Review

Dupilumab was first approved for the treatment of atopic dermatitis (AD) and blocks the signaling of interleukin (IL)-4 and -13. Several other chronic skin conditions share mechanistic overlaps with AD in their pathophysiology, i.e., are linked to type 2 inflammation. Most recently, dupilumab was approved by the U.S. Food and Drug Administration for prurigo nodularis (PN). Given its relatively good safety profile, effective off-label use of dupilumab has been reported for a multitude of dermatologic diseases and several clinical trials for dermatologic skin conditions are currently ongoing. We conducted a systematic review of applications of dupilumab in dermatology other than AD and PN by searching the databases PubMed/Medline, Scopus, Web of Science and Cochrane Library as well as the clinical trial registry ClinicalTrials.gov. We found several reports for effective treatment of bullous autoimmune diseases, eczema, prurigo, alopecia areata, chronic spontaneous urticaria, Netherton syndrome and a variety of other chronic inflammatory skin diseases.

A real-world observational study of dupilumab treatment in adult patients with prurigo nodularis

BACKGROUND

Prurigo nodularis (PN) is a chronic inflammatory skin condition that has a significant unmet needs for effective treatment options.

OBJECTIVE

To assess the efficacy and safety of dupilumab in adult patients with PN refractory to traditional therapies.

METHODS

This ongoing, real-life study examined dupilumab treatment in 8 adult patients diagnosed with PN for at least 6 months. The included patients were prescribed 300 mg dupilumab biweekly for at least 16 weeks. Efficacy was the primary outcome by means of multiple standardized scale measurements while safety was also reported.

RESULTS

PN patients treated with dupilumab showed notable clinical improvement. After 16 weeks of dupilumab treatment, the mean Investigator Global Assessment (IGA) score reduced from 3.75 to 1.50. Patients mean Numerical Rating Scale Itch Intensity (NRSI), Dermatology Life Quality Index (DLQI), and Hospital Anxiety and Depression Scale (HADS) ratings reduced from 8.625, 15.13, and 14.50 to 1.563, 4.625, and 1.000 respectively. The majority of the patients (87.5%) reported dupilumab as effective while no adverse events have been reported.

STUDY LIMITATIONS

This study was limited to a small cohort of adult PN patients and a short-time observation period.

CONCLUSIONS

Dupilumab is effective and tolerable in adult PN patients with significant improvement in skin lesions, itching, and quality of life.

Dupilumab for the treatment of prurigo nodularis: A systematic review

Background

Conventional treatment techniques have limited efficacy and more side effects in the treatment of prurigo nodularis. The better alternative treatment option for better outcomes of the disease is dupilumab.

Objective

The objective of this study was to systematically review dupilumab-related treatment outcomes in prurigo nodularis.

Methods

Several databases like Embase, PubMed, Web of Science, and Cochrane library were searched for data acquisition on October 8, 2022. Based on Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, 24 publications were included in this study.

Results

After 4,12,16 and more than 16 weeks of dupilumab treatment, 8.3% (n=5/60), 34.4% (n=11/32), 3.6% (n=2/56), and 45.3% (n=29/64) of patients had complete remission, respectively. In addition, 85.0% (n=51/60), 59.4% (n=19/32), 83.9% (n=47/56), and 43.8% (n=28/64) had partial remission, respectively. Moreover, 6.7% (n=4/60), 6.3% (n=2/32), 12.5% (n=7/56), and 10.9% (n=7/64) showed no remission, respectively, and significant reduction of numeric rating scale itch intensity (from 9.0 to 4.9, 2.1, 2.8, 0.9) was attained. There were no serious adverse events observed during treatment, but the most common event observed was conjunctivitis (12.6%, n=15/119).

Conclusions

Dupilumab has definite effectiveness and safety in prurigo nodularis treatment.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier (CRD42022365802).

Hypereosinophilic Dermatitis: Successful Treatment with Dupilumab

Hypereosinophilic dermatitis (HED) is a subtype of hypereosinophilic syndrome. HED is characterized by eosinophilic granulocytes increased in peripheral blood and bone marrow and infiltrated in skin. The clinical manifestations of HED are diffussed by erythema, papule and maculopapule with severe itching. The etiology of HED is unknown. At present, in addition to HED with FIP1L1-PDGFRA fusion gene positive, whose treatment is tyrosine kinase inhibitor, other types of HED first-line treatment are oral glucocorticoids, supplemented by antihistamines and immunosuppressants. Dupilumab is a human monoclonal antibody, which inhibits the IL-4 and IL-13 signaling by binding to the IL-4R-α and IL-13R-α-1 subunits of the receptor. We report a 76-year-old male patient with HED whose peripheral blood eosinophils decreased from 20.7% to 4.1% after 8 weeks of dupilumab, and his pruritus was completely relieved. Dupilumab was discontinued after 6 months of treatment. It is exciting that the patient has not experienced relapse for 17 months after the discontinuation. No adverse event was reported.

Clinical phenotypes of adult atopic dermatitis and related therapies

PURPOSE OF REVIEW

To report current knowledge on the different clinical phenotypes of adult atopic dermatitis. Possible therapeutic intervention in relation to phenotype is also evaluated.

RECENT FINDINGS

Atopic dermatitis is a chronic inflammatory disease affecting up to 10% of adults. It can manifest with different clinical phenotypes, causing diagnostic difficulties. Long-term is often required and systemic drugs are needed for moderate-to-severe forms. However, few drugs are registered for atopic dermatitis in many countries. Furthermore, limited data exist regarding the treatment in relation to individual clinical phenotypes.

SUMMARY

Currently, the most relevant data are those for cyclosporine, alitretinoin, and dupilumab. Cyclosporine and dupilumab showed to be effective in the treatment of atopic dermatitis, although in trials and real-life experiences the different phenotypes treated are usually not reported. However, cyclosporine appears to be effective in prurigo nodularis. Alitretinoin is reported to be particularly efficacious for atopic dermatitis of the hands, while it is ineffective for other locations of the disease. Dupilumab demonstrated its efficacy in prurigo nodularis and nummular eczema phenotypes of atopic dermatitis; moreover, especially in elderly patients, its effectiveness seems to be faster if the folds of the limbs are involved.

Efficacy of dupilumab in chronic prurigo and chronic idiopathic pruritus: A systematic review of current evidence and analysis of response predictors

Dupilumab has demonstrated a great reduction on chronic pruritus that is the hallmark of atopic dermatitis (AD). Underscoring relevant pathogenesis similarities emerging from AD, chronic idiopathic pruritus (CIP) and chronic prurigo (CP), several authors suggested the beneficial role of dupilumab in these conditions. The evidence on this subject is limited with no precise data available. In this study, we carried out a systematic literature review in order to evaluate the efficacy of dupilumab on both pruritus and skin manifestations in the two largest retrospective cohorts of patients with CP and CIP and tried to identify potential response predictors. Electronic searches were conducted on 4 databases. Our primary outcome was the improvement in pruritus measured by a reduction in patient's reported numerical rating scale of itch (NRSI) by > 4. Secondary outcomes included: proportion of patients with complete response at the end of treatment, reduction in the number of lesions by the Investigator Global Assessment (IGA), improvement in numerical rating scale of sleep (NRSS), improvement in quality of life measured by the Dermatology Life Quality Index (DLQI), time until patient perceived any improvement (Time-First) and time until patient reported absence of pruritus (Time-Final). Descriptive statistics were calculated for each demographic and clinical variable. Univariate logistic regression analyses were conducted to explore association between response to dupilumab and potential predictive factors. We included 25 articles in the analysis, counting a total of 153 patients. Based on CP patients' cohort (n=132), the mean NRSI at baseline was 8.79 ±0.86 and the NRSI final was 2.32 ±1.27. The mean time to first improvement was 5.18 ±3.13 weeks, while the time to complete improvement of pruritus (Time-final) was 13.6 ±12.0 weeks. Ninety patients out of 109 (83%) noticed improvement in pruritus before 4 weeks of dupilumab therapy. At the end of treatment, 18 patients out of 126 (14%) had a complete remission of pruritus and 110 patients out of 123 (89%) had a reduction of NRSI > 4. The reduction in NRSI was significantly greater in patients improving before 4 weeks of treatment (6.57 ±1.71) compared to patients improving in more than 4 weeks (5.49 ±1.39, p<0.001). Patients with history of AD and those who have been previously treated with cyclosporine or methotrexate had a significantly lower reduction in NRSI (e.g. 6.05 ±1.34 vs 7.08 ±1.90 p<0.01 for non-associated AD patients). Based on CIP patient's cohort (n=21), the mean NRSI at baseline was 8.33 ±0.80 and the NRSI final was 0.95 ±0.59. The mean time to first improvement was 2 ±0 weeks, while the time to complete improvement (Time-final) was 14.6 ±10 weeks. At the end of treatment, 3 patients out of 21 (14%) had a complete remission of pruritus and 100% of patients had a reduction of NRSI > 4. No serious treatment-emergent adverse events were reported. The most common adverse event was mild conjunctivitis (13 cases). We highlight the importance of one early sign of improvement as predictor of the future response to dupilumab: the improvement before 4 weeks of treatment that leads significantly to a greater final reduction in NRSI. Furthermore, patients with the presence or history of atopy appear to be less responsive to dupilumab than non-atopic patients and develop more side effects, in particular conjunctivitis.

Immunotargets and Therapy for Prurigo Nodularis

Prurigo nodularis is a chronic inflammatory skin disease consisting of severely pruritic nodules that can be very debilitating for patients. The basis of this skin condition is immunological dysregulation and neural amplification, driven by T-lymphocytes, mast cells, eosinophilic granulocytes, macrophages, and cytokines mediating itchy processes. Further complicating this already taxing diagnosis is the lack of approved treatment and consensus on management; although there are off-label treatments utilized as therapy. Immunomodulators are the cornerstone of treatment for PN, and additional novel therapies targeting key players in the immunological cascade are currently undergoing investigation. In this review, we will highlight targets of the immune cascade and explore current immunomodulating treatments as well as immunotherapies on the horizon for the management of prurigo nodularis.

Neuro-immune communication regulating pruritus in atopic dermatitis

Atopic dermatitis (AD) is a common, chronic-relapsing inflammatory skin disease with significant disease burden. Genetic and environmental trigger factors contribute to AD, activating two of our largest organs, the nervous and immune system. Dysregulation of neuro-immune circuits plays a key role in the pathophysiology of AD causing inflammation, pruritus, pain, and barrier dysfunction. Sensory nerves can be activated by environmental or endogenous trigger factors transmitting itch stimuli to the brain. Upon stimulation, sensory nerve endings also release neuromediators into the skin contributing again to inflammation, barrier dysfunction and itch. Additionally, dysfunctional peripheral and central neuronal structures contribute to neuroinflammation, sensitization, nerve elongation, neuropathic itch, thus chronification and therapy-resistance. Consequently, neuro-immune circuits in skin and central nervous system may be targets to treat pruritus in AD. Cytokines, chemokines, proteases, lipids, opioids, ions excite/sensitize sensory nerve endings not only induce itch but further aggravate/perpetuate inflammation, skin barrier disruption, and pruritus. Thus, targeted therapies for neuro-immune circuits as well as pathway inhibitors (e.g., kinase inhibitors) may be beneficial to control pruritus in AD either in systemic and/or topical form. Understanding neuro-immune circuits and neuronal signaling will optimize our approach to control all pathological mechanisms in AD, inflammation, barrier dysfunction and pruritus.

A New Era with the Development of Cytokine-Based Therapy for Pruritus

Pruritus is a common dermatological condition and negatively impacts QOL. Persistent pruritus and excessive scratching behavior can lead to the itch-scratch cycle that exacerbates inflammatory skin diseases. Conventional antipruritic drugs, such as antihistamines, corticosteroids, or anticonvulsants, are sometimes insufficient. Recently, however, molecularly targeted drugs, such as IL-31 or IL-4 receptor-targeting antibodies, have become available or are under clinical trials, dramatically changing the clinical situation. In fact, some of these drugs can improve pruritus without the need for topical steroids. Taken together, these observations point to the importance of cytokine-mediated pruritus, further understanding of which may guide improved therapies.

Therapeutic potential of biologics in prurigo nodularis

INTRODUCTION

Prurigo nodularis (PN) or chronic prurigo of nodular type (CNPG) is a subtype of chronic prurigo with severe pruritus and neuroimmune underlying pathophysiology occurring in a plethora of dermatological, systemic, neurologic, and psychiatric conditions.

AREAS COVERED 

We review the increasing repertoire of biologics in the treatment of CNPG focusing on those targeting interleukins 4, 13, 31, oncostatin M and IgE. Presented information is based on a database research on current clinical trials (clinicaltrials.gov, European Clinical Trials Database (EudraCT), US clinical trial registry ICH-GCP) and a PubMed search for latest publications conducted with the combinations of the terms 'chronic prurigo,' 'prurigo nodularis,' 'pathophysiology,' 'treatment,' 'therapy', and 'biologics.'

EXPERT OPINION

CNPG gets more and more attention as new therapeutic targets have been revealed in recent years, thus allowing the use of targeted approaches. The off-label advent of dupilumab offered advanced insight into the pathogenesis of CNPG and showed an impressive relief of pruritus in the vast majority of patients. New therapies including biologics (e.g. nemolizumab, tralokinumab, lebrikizumab), small molecules (e.g. neurokinin-1 receptor antagonists, janus kinase inhibitors) as well as mu-opioid receptor antagonists and nalbuphine, a μ-antagonist/κ-agonist, are in the pipeline and offer new hope for an improved future patient care.

Prominent Role of Type 2 Immunity in Skin Diseases-Beyond Atopic Dermatitis

Type 2 immunity, illustrated by T helper 2 lymphocytes (Th2) and downstream cytokines (IL-4, IL-13, IL-31) as well as group 2 innate lymphoid cells (ILC2), is important in host defense and wound healing.¹ The hallmark of type 2 inflammation is eosinophilia and/or high IgE counts and is best recognized in atopic diathesis. Persistent eosinophilia, such as seen in hypereosinophilic syndromes, leads to fibrosis and hence therapeutic Type 2 inhibition in fibrotic diseases is of high interest. Furthermore, as demonstrated in cutaneous T cell lymphoma, advanced disease is characterized by Th1 to Th2 switch allowing cancer progression and immunosuppression. Development of targeted monoclonal antibodies against IL-4Rα (eg, dupilumab) led to a paradigm shift for the treatment of atopic dermatitis (AD) and stimulated research to better understand the role of Type 2 inflammation in other skin conditions. In this review, we summarize up to date knowledge on the role of Type 2 inflammation in skin diseases other than AD and highlight whether the use of Type 2 targeted therapies has been documented or is being investigated in clinical trials. This manuscript reviews the role of Type 2 inflammation in dermatitis, neurodermatitis, IgE-mediated dermatoses (eg, bullous pemphigoid, chronic spontaneous urticaria), sclerodermoid conditions and skin neoplasms.

The emerging role of dupilumab in dermatological indications

INTRODUCTION

Dupilumab represents a breakthrough in the management of atopic dermatitis (AD), thanks to its powerful T-helper (Th)2-mediated immunity modulating activity. It can reduce the atopic skin molecular signature and induce a significant decrease in the clinical signs and symptoms of AD patients.

AREAS COVERED

Th2 activation has been confirmed or suspected in skin diseases other than AD, and several reports about the treatment with dupilumab in these conditions have been published. In order to review the new indications of dupilumab in dermatology, we performed a search on PubMed, Embase, Cochrane Skin databases, and clinicaltrials.gov.

EXPERT OPINION

The analysis of available literature suggests that dupilumab may have a large application in dermatology, besides AD. Clinical trials are underway on some widespread disease (i.e. chronic urticaria, bullous pemphigoid, alopecia areata, or allergic contact dermatitis). The data are still partial, but they seem to indicate that dupilumab is efficacious and safe. On the other hand, the dupilumab use in some rare skin diseases remains only hypothetical or linked to few case reports. Dupilumab could have a prominent position in the therapeutic algorithm of chronic skin diseases that significantly affect the quality of life of patients, require long-term treatment, or lacking effective therapies.

Effectiveness of Dupilumab for an Elderly Patient with Prurigo Nodularis Who Was Refractory and Contradicted to Traditional Therapy

Prurigo nodularis (PN) is an intense pruritic skin condition. Treatment of PN is challenging. We described an elderly patient with PN who had contradictions of cyclosporine or methotrexate and achieved significant improvement after treatment with dupilumab. We also reviewed published cases of elderly patients with PN who were refractory to traditional therapy.

Dupilumab as promising treatment for prurigo nodularis: current evidences

Prurigo nodularis (PN) is a debilitating chronic disease characterized by intense itching and excoriated hyperkeratotic nodules distributed on the trunk and extremities, especially the extensor surfaces. The pathophysiology includes complex and not yet well-understood mechanisms involving inflammation and dysregulation of the nervous system. Currently, there are no approved therapies by the Food and Drug Administration (FDA) and the few treatment approaches for this condition are often ineffective and related to severe side effects. An emerging therapeutic option is dupilumab, a monoclonal antibody for adults and adolescents with moderate-to-severe atopic dermatitis, that inhibits interleukin-4 receptor alpha subunit (IL4-Rα) and the signaling pathways activated by interleukin (IL)-4 and IL-13. These cytokines seem to be involved in the development and perpetuation of PN and other type-2 inflammation diseases. Data on this topic are limited, but the emergent positive effects of this drug, reported in the literature and summarized in this review, suggest that it can be a safe and efficient therapy in PN.

Dupilumab for pediatric prurigo nodularis: A case report

Herein we report on a 9-year-old girl with recalcitrant prurigo nodularis unresponsive to multiple standard treatments. She was started on dupilumab therapy with rapid improvement in pruritus within 2 weeks and near complete regression of lesions at 3 months. Dupilumab should be considered as an off-label treatment for refractory prurigo nodularis in children.

Pathophysiology, diagnosis, and pharmacological treatment of prurigo nodularis

Introduction: Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by intensely pruritic, hyperkeratotic nodules distributed on the trunk and extensor surfaces of the extremities. PN has a profoundly negative impact on sleep and quality of life in patients with PN. There are currently no U.S. Food and Drug Administration-approved agents and patients are often recalcitrant to current therapies, highlighting the importance of further research into this severely debilitating condition. Areas covered: A PubMed search was conducted to find available literature on the pathophysiology and clinical management of PN. In this review article, we discuss the current understanding of the pathophysiology, recommended diagnostic approach, and treatment options available for PN. Expert opinion/commentary: PN is an extremely difficult condition to treat, because there is a lack of effective therapies available due to our limited understanding of its pathophysiology. Currently, available treatment options are often multimodal due to the intersection of neuroimmune etiologic factors in the pathogenesis of PN. Fortunately, as our knowledge of PN expands, novel treatments targeting specific molecular biomarkers of PN are emerging, providing hope to this long-suffering patient population.

Emerging Therapeutic Options for Chronic Pruritus

Chronic pruritus, defined as an unpleasant sensation resulting in a need to scratch that lasts more than 6 weeks, is a prevalent and bothersome symptom associated with both cutaneous and systemic conditions. Due to complex pathogenesis and profuse contributing factors, chronic pruritus therapy remains challenging. Regardless of the well-established antipruritic properties of classic pharmacotherapy (topical therapy, phototherapy and systemic therapy), these methods often provide insufficient relief for affected individuals. Owing to the growing interest in the field of pruritic research, further experimental and clinical data have emerged, continuously supporting the possibility of instigating novel therapeutic measures. This review covers the most relevant current modalities remaining under investigation that possess promising perspectives of approval in the near future, especially opioidergic drugs (mu-opioid antagonists and kappa-opioid agonists), neurokinin-1 receptor antagonists, biologic drugs, Janus kinase inhibitors, ileal bile acid transporter inhibitors, aryl hydrocarbon receptor agonists and histamine H₄ receptor antagonists.

Practical approaches for diagnosis and management of prurigo nodularis: United States expert panel consensus

BACKGROUND

Prurigo nodularis (PN) is a chronic disease characterized by intensely pruritic, raised, nodular lesions. Because there are currently no United States Food and Drug Administration-approved therapies specifically for PN, management is highly variable, and no consensus exists on treatment regimens.

OBJECTIVE

To provide practical guidance to help United States dermatologists diagnose and effectively treat patients with PN.

METHODS

We participated in a roundtable discussion to develop consensus recommendations on diagnosis and treatment of PN from a United States perspective.

RESULTS

The core findings in PN are the presence of firm, nodular lesions; pruritus lasting at least 6 weeks; and a history or signs, or both, of repeated scratching, picking, or rubbing. The diagnostic workup involves a complete review of systems, considering potential systemic diseases, and assessment of disease severity, including disease burden and pruritus intensity. Treatment should be selected based on a patient's clinical presentation, comorbidities, and response to prior treatments and should address both neural and immunologic components of pruritus.

LIMITATIONS

Data on PN are from anecdotal or small clinical trials, and all treatments are currently used off-label.

CONCLUSION

An effective treatment approach for patients with PN should be based on clinical judgment and tailored to the individual needs of the patient.

Dupilumab after the 2017 approval for the treatment of atopic dermatitis: what's new and what's next?

PURPOSE OF REVIEW

The IL-4/13 antagonist dupilumab was approved in 2017 as the first biologic for atopic dermatitis. Here, we comprehensively review compelling new data regarding dupilumab published following the approval.

RECENT FINDINGS

Daily clinical practice reports of dupilumab in atopic dermatitis are favorable and in line with the registration trials. Dupilumab does not appear to negatively affect pharmacokinetics of CYP450-metabolized drugs nor vaccination responses. Type 2 inflammation biomarkers in skin and serum are reduced following dupilumab treatment. Dupilumab increases the risk for conjunctivitis, especially with higher baseline atopic dermatitis severity and a history of conjunctivitis, but the underlying mechanisms are unknown. Favorable effects of dupilumab have been reported in treatment-recalcitrant hand eczema and prurigo nodularis cases; for allergic contact dermatitis and alopecia areata, there are conflicting responses to dupilumab, possible stemming from pathophysiological heterogeneity.

SUMMARY

Daily practice data support the continued use of dupilumab for atopic dermatitis. The only safety signal is an increased risk for conjunctivitis; mechanistic studies into dupilumab-associated conjunctivitis should lead to risk mitigation strategies. Prospective, controlled evaluations are needed for dupilumab in hand eczema and prurigo nodularis. A precision medicine-driven drug-development approach is essential to assess dupilumab for diseases with heterogeneous pathophysiologies, such as alopecia areata and allergic contact dermatitis.

Resolution of Treatment-Refractory Prurigo Nodularis With Dupilumab: A Case Series

Prurigo nodularis is a pruritic skin condition that can present therapeutic challenges. We present a series of three patients diagnosed with prurigo nodularis who had failed several commonly trialed therapies, but experienced relief from symptoms and improvement in skin lesions following initiation of dupilumab therapy. All patients in this series lacked a diagnosis of atopic dermatitis and had lesions on the lower extremities, although other locations such as the trunk were also involved. Continued study of dupilumab in patients with prurigo nodularis is advocated.

Prurigo nodularis: Pathogenesis and management

Prurigo nodularis is a chronic skin condition characterized by severely pruritic nodules that cause a profound negative impact on quality of life. The second article in this 2-part continuing medical education series focuses on reviewing the pathogenesis of prurigo nodularis and exploring management algorithms for this condition. In addition, we discuss some emerging and novel therapies for treating prurigo nodularis. The first article in this 2-part series describes the broader epidemiology, patient demographics, physical examination findings, and symptoms to aid in the timely recognition and diagnosis of prurigo nodularis.

Efficacy of dupilumab in prurigo nodularis in elderly patient

Prurigo nodularis (PN) is a chronic disorder, affecting adults, with multiple nodules, typically on the limbs. The treatment is challenging, especially in elderly patients. An 85-year-old woman had developed in the last 3 years itch with nodular lesions and erythematous scaly patches and excoriations. The extension of the lesions was evaluated by body surface area (BSA) score and the patient's itch and disease-related sleep disorders by a Numeric Rating Scale (NRS) from 0 to 10. The Dermatology Life Quality Index (DLQI) and blood chemistry were performed before and during the therapy. At the baseline, the BSA score was 56%. Itch and disease-related sleep disorders were, respectively, NRS 10 and 5 and DLQI was 9. Total IgE count and lactate dehydrogenase were increased. After starting dupilumab, there was a rapid improvement, especially in pruritus. The patient reported the maximum peak of pruritus every day for 6 months. At this time, the itch almost disappeared and clinically only postinflammatory lesions appreciated, with normalization of the blood tests and without any side effects.

The Neuromodulatory Effect of Antipruritic Treatment of Chronic Prurigo

Chronic prurigo is an extremely severe pruritic skin disease which presents with multiple, hyperkeratotic and erosive papules, nodules and/or plaques. Patients with this high-burden disease require effective therapies, but effective treatments with regulatory agency approval are currently lacking. Deeper understanding of the pathophysiology suggests that hypersensitive nerves play an important role in the development of chronic prurigo. Accordingly, a treatment with neuroactive substances which modulate hypersensitivity seems promising. Here, we review antipruritic therapies with a neuromodulative effect. Current treatment options, such as topical capsaicin or opioid-receptor modulators, and also novel and future treatment regimens, such as, for example, interleukin-31 antibodies and neurokinin-1 receptor antagonists, are discussed.

Pruritus in allergy and immunology

Although evolutionarily conserved to expel ectoparasites and aid in the clearance of toxins and noxious environmental stimuli from the host, the type 2 immune response can become pathologic in the setting of a variety of allergic disorders. Itch can be a behavioral extension of type 2 immunity by evoking scratching and, in the setting of disease, can become chronic and thus highly pathologic as well. Classically, our understanding of itch mechanisms has centered around the canonical IgE-mast cell-histamine axis. However, therapies aimed at blocking the histaminergic itch pathway have been largely ineffective, suggesting the existence of nonhistaminergic itch pathways. Indeed, recent advances in itch biology have provided critical new insight into a variety of novel therapeutic avenues for chronic itch in the setting of a number of allergic disorders. Here we highlight how these new developments will likely inform the problem of pruritus in a variety of well-established and emerging conditions in the field of allergy.

Chronic Pruritus Responding to Dupilumab-A Case Series

Background: Chronic pruritus is defined as itch lasting for greater than six weeks. Pruritus is a burdensome manifestation of several internal and external disease states with a significant impact on quality of life. Dupilumab has shown promise in treating a number of conditions including atopic dermatitis (AD) and asthma. Its success in reducing pruritus in AD has generated interest regarding its potential application in other pruritic conditions, such as chronic pruritus of unknown origin, uremic pruritus, and pruigo nodularis. Methods: In this retrospective analysis, we present a series of 20 recalcitrant pruritus patients seen at a tertiary center treated with off-label dupilumab at standard AD dosing. Results: Dupilumab was successful at reducing itch in all treated patients, leading to complete resolution in 12/20 patients and an overall mean NRSi reduction of 7.55. Dupilumab was well tolerated with no significant adverse effects. Conclusions: Our case series suggests dupilumab may be a safe and efficacious therapeutic option in several pruritic conditions and demonstrates the need for further studies to better ascertain its place in the pruritus treatment armamentarium.