Evaluation of Ixekizumab Treatment for Patients With Pityriasis Rubra Pilaris: A Single-Arm Trial

Rapid clearance of extensive juvenile pityriasis rubra pilaris with ixekizumab

Juvenile pityriasis rubra pilaris is a rare inflammatory skin disorder currently without any FDA-approved treatments, and lesions can be refractory to conventional treatment with topical corticosteroids, methotrexate, and oral retinoids. We herein present a case of a 6-year-old boy who attained clearance of extensive juvenile pityriasis rubra pilaris within 2 weeks of starting ixekizumab therapy. Therapeutic effect has been durable at 6 months, and patient continues on therapy without adverse effects. Our case highlights a new, rapidly effective treatment option for pediatric patients with this rare condition.

Severe pityriasis rubra pilaris complicated with Kaposi's varicelliform eruption and cutaneous MRSA infection case report

A 62-year-old woman presented to our hospital with erythroderma affecting 100 % of body surface area, skin scaling and a body temperature of 37.3o C. The lesions initially appeared on her scalp 6 months prior, then psoriasis was diagnosed. Topical corticosteroids were prescribed, which were ineffective. After 2 months the rash spread to the rest of the body, accompanied by nail changes and hair loss. The patient was subsequently admitted to the local hospital, where following clinical evaluation, oral methotrexate 10 mg once weekly was initiated for 6 weeks. Despite the administered treatment the patient's health and skin condition deteriorated, manifesting with an appearance of new lesions. By the time of admission to our hospital erythroderma affecting 100 % of body surface area covered with wide skin scales and punched-out erosions on the torso, lower eyelid ectropion, loss of scalp hair and thickened yellow nail plates were observed. Skin biopsy revealed histological changes consistent with pityriasis rubra pilaris diagnosis. Polymerase chain reaction test from erosions confirmed the presence of herpes simplex virus 1/2 and culture results identified methicillin-resistant Staphylococcus aureus. Given the considerations of pityriasis rubra pilaris, hematologic disorders and paraneoplastic syndrome, a comprehensive work-up for haematological and oncological disorders was conducted, which yielded no significant findings. The patient was treated with intravenous corticosteroids, antibiotics, and antiviral drugs. Isotretinoin was initiated following the histological confirmation of pityriasis rubra pilaris. By the time of discharge, the patient's condition improved. During a follow-up visit 43 weeks after the initiation of isotretinoin, the skin was almost clear. The described case highlights the rare possibility of developing Kaposi's varicelliform eruption in patients with pityriasis rubra pilaris and demonstrates that isotretinoin is a safe and effective treatment option for this condition.

Targeting IL-1 controls refractory pityriasis rubra pilaris

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disease with a poorly understood pathogenesis. Through a molecularly driven precision medicine approach and an extensive mechanistic pathway analysis in PRP skin samples, compared to psoriasis, atopic dermatitis, healed PRP, and healthy controls, we identified IL-1β as a key mediator, orchestrating an NF-κB-mediated IL-1β-CCL20 axis, including activation of CARD14 and NOD2. Treatment of three patients with the IL-1 antagonists anakinra and canakinumab resulted in rapid clinical improvement and reversal of the PRP-associated molecular signature with a 50% improvement in skin lesions after 2 to 3 weeks. This transcriptional signature was consistent with in vitro stimulation of keratinocytes with IL-1β. With the central role of IL-1β underscoring its potential as a therapeutic target, our findings propose a redefinition of PRP as an autoinflammatory keratinization disorder. Further clinical trials are needed to validate the efficacy of IL-1β antagonists in PRP.

Role of IL-23 inhibitors including risankizumab and guselkumab in the treatment of pityriasis rubra pilaris

Pityriasis rubra pilaris (PRP) is a rare and chronic inflammatory dermatologic condition characterized by hyperkeratotic salmon-colored plaques and palmoplantar keratoderma. Traditional therapeutic modalities have shown limited efficacy and often entail potential adverse effects, highlighting the need for alternative treatment options. Our review aims to summarize the current evidence on the off-label use of IL-23 inhibitors, risankizumab and guselkumab, in the treatment of PRP. These biologic agents have been approved for psoriasis, and their potential role in managing PRP has recently garnered interest. We conducted a comprehensive literature search on PubMed and Scopus databases, identifying relevant studies published in English up to June 2023 following PRISMA guidelines. A total of 10 studies were selected for data extraction and review. Results from the selected studies demonstrated encouraging outcomes with both risankizumab and guselkumab in managing PRP. Among 11 patients treated with risankizumab, 10 showed notable improvements in various disease manifestations, including pruritus, erythema, and affected body surface area. DLQI scores and BSA percentages reported a significant improvement before and after risankizumab treatment (p = 0.0322; p = 0.0216). However, two cases also reported symptom aggravation or even disease worsening. Patients treated with guselkumab exhibited ultimate improvement in all five cases, with complete clearance in three out of five cases. DLQI and BSA percentages also reported significant improvement with treatment with guselkumab (p = 0.0172; p < 0.0001). While most cases demonstrated positive outcomes, there were isolated instances of worsening symptoms, emphasizing the need for caution and further investigation. Further research with larger sample sizes and longer follow-up periods is necessary to establish the efficacy, optimal dosing, and long-term safety of risankizumab and guselkumab in treating PRP. Overall, we provide valuable insights into the potential use of IL-23 inhibitors, risankizumab, and guselkumab, as promising treatment options for PRP. These biologics have shown efficacy in improving symptoms in treatment-resistant cases, offering new avenues for clinicians to explore in the treatment of PRP.

Guselkumab for Pityriasis Rubra Pilaris and Dysregulation of IL-23/IL-17 and NFkB Signaling: A Nonrandomized Trial

Importance

There is no US Food and Drug Administration-approved treatment for pityriasis rubra pilaris (PRP), and it is common for patients to fail to experience improvement with several systemic options. Involvement of interleukin (IL) 23 suggests a potential therapeutic target.

Objective

To determine whether guselkumab, an IL-23p19 inhibitor, provides clinical improvement for participants with PRP and better understand gene and protein dysregulation in PRP.

Design, Setting, and Participants

This single-arm, investigator-initiated nonrandomized trial was conducted from October 2019 to August 2022 at a single-center academic university with participants from 8 states in the US. In total, 14 adults with moderate to severe PRP were enrolled; 12 completed the trial. Age-matched and sex-matched healthy controls provided skin and blood for proteomic and transcriptomic studies. The primary outcome was observed at 24 weeks, and additional follow-up occurred at 36 weeks.

Intervention

Guselkumab is a fully human immunoglobulin G1 λ monoclonal antibody that selectively binds and inhibits the p19 subunit of IL-23. Subcutaneous injections were given at the US Food and Drug Administration-approved dosing schedule for psoriasis over a 24-week period.

Main Outcomes and Measures

The primary outcome was the mean change in the Psoriasis Area Severity Index (PASI) score at week 24. Secondary outcomes included pruritus, Dermatology Life Quality Index score, clinical response at week 36, and association with transcriptomics and proteomics expression.

Results

A per-protocol analysis was performed for the cohort of 4 female and 8 male patients who had a mean (SD) age of 56.5 (18.7) years. The mean improvement in PASI score, pruritus, and Dermatology Life Quality Index score was 61.8% (P < .001), 62.3% (P = .001), and 60.2% (P < .001), respectively. Nine participants (75%) achieved a 50% improvement in PASI. Among these clinical responders, at week 36, 8 of 9 achieved PASI75, and 6 of 9 achieved PASI90. No participants had pathogenic CARD14 gene variations. There was 1 serious adverse event that was not associated with the study drug. Proteomics and gene expression profiles identified dysregulation of a predominance of inflammatory pathways (such as T helper 17 and nuclear factor κ B) in participants with PRP who later responded well to treatment with guselkumab and stronger dysregulation of keratinocyte development pathways in individuals who did not respond to guselkumab.

Conclusion and Relevance

The results of this nonrandomized trial suggest that guselkumab has efficacy in treating refractory moderate to severe adult PRP.

Trial Registration

ClinicalTrials.gov Identifier: NCT03975153.

Pityriasis Rubra Pilaris: An Updated Review of Clinical Presentation, Etiopathogenesis, and Treatment Options

Pityriasis rubra pilaris (PRP) is a rare papulosquamous reaction pattern with a significant impact on quality of life. Type I PRP is the most common PRP variant, presenting as erythematous papules emerging in a follicular distribution and later coalescing into plaques with characteristic islands of sparing; histologically, an alternating pattern of orthokeratosis and parakeratosis is considered the hallmark of PRP (checkerboard hyperkeratosis). Other PRP variants (types II-V) differ in their age of onset and clinical presentation. Type VI PRP is a rare PRP subtype associated with human immunodeficiency virus infection and is occasionally associated with diseases of the follicular occlusion tetrad. Caspase recruitment domain family, member 14 (CARD14)-associated papulosquamous eruption and facial discoid dermatitis are newly described disease states that have an important clinical overlap with PRP, creating shared conundrums with respect to diagnosis and treatment. The etiology inciting PRP often remains uncertain; PRP has been suggested to be associated with infection, malignancy, or drug/vaccine administration in some cases, although these are based on case reports and causality has not been established. Type V PRP is often due to inborn CARD14 mutations. Furthermore, recent literature has identified interleukin-23/T-helper-17 cell axis dysregulation to be a major mediator of PRP pathogenesis, paving the way for mechanism-directed therapy. At present, high-dose isotretinoin, ixekizumab, and secukinumab are systemic agents supported by single-arm prospective studies; numerous other agents have also been trialed for PRP, with variable success rates. Here, we discuss updates on clinical manifestations, present new insights into etiopathogenesis, and offer a survey of recently described therapeutic options.

Case report: Area of focus of management of severe pityriasis rubra pilaris by dose optimization of adalimumab biosimilar in combination with acitretin and montelukast

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disorder characterized by hyperkeratotic follicular papules, orange-red scaling plaques with islands of sparing and palmoplantar keratoderma. While spontaneous resolution occurs in some cases, treatment can be challenging for others. The use of biologics in PRP management has gained attention in recent studies, although their high costs and potential side effects present limitations. We present a case of a 71-year-old patient with treatment-resistant PRP who showed significant improvement through optimized adalimumab treatment. Considering the emerging role of phospholipase A2 in PRP pathogenesis, montelukast was added, further enhancing the therapeutic response. By maintaining montelukast and prolonging the adalimumab interval to 3 and 4 weeks, effective dose optimization was achieved without PRP relapse. This case report highlights the potential for adalimumab dose optimization by shortening the initial treatment interval for increased effectiveness and lengthening the interval during the maintenance phase to conserve medication doses. Montelukast appears to assist in sustaining clinical outcomes during interval prolongation, necessitating further investigation through additional studies.

The Effectiveness of Anti-Interleukin-17A Treatment for Pityriasis Rubra Pilaris: A Systematic Review

Anti-interleukin-17A (anti-IL-17A) therapy has been increasingly employed as a treatment option for pityriasis rubra pilaris (PRP). In this study, we reviewed all available studies on this topic in the literature to evaluate the efficacy and safety of anti-IL-17A. Our main objective was to assess the current evidence on the efficacy and safety of anti-IL-17A therapy in the management of PRP. We searched for relevant articles on PubMed, MEDLINE, Ovid, Embase, and the Web of Science electronic databases from inception until 2022. Our inclusion criteria were as follows: randomized controlled trials (RCTs), quasi-randomized trials, or prospective observational studies that include PRP patients treated with biological treatments; studies that report clinical outcomes; and studies that compare the treatment modalities, including anti-IL-17, in the English language. A total of 19 articles involving 77 cases were reviewed after applying the inclusion criteria and removing duplicates. We found that type 1 PRP was the most common condition irrespective of gender, and the trunk was the most affected area. The study showed that IL-17 inhibitors had a significant impact on the patients. However, higher-level studies are required to further evaluate the therapeutic and safety effects of the treatment.

Kaposi's Varicelliform Eruption After Treatment With Ixekizumab in a Patient With Pityriasis Rubra Pilaris

Pityriasis rubra pilaris (PRP) is a rare condition characterized by red-orange plaques with islands of sparing with follicular and palmoplantar hyperkeratosis. The disease can be difficult to treat and often requires patients to trial multiple therapeutic options. In recent years, targeted biologic therapies have increasingly been trialed due to their relative efficacy and favorable safety profile. Ixekizumab, an interleukin-17 inhibitor, is one such therapy that has demonstrated efficacy in PRP with few reported adverse events. We present a PRP patient who developed Kaposi's varicelliform eruption followed by a pseudomonal superinfection three months after initiation of ixekizumab.

Treatment Options for Juvenile Pityriasis Rubra Pilaris

Pityriasis rubra pilaris represents a group of familial and acquired disorders of cornification that affect both adult and pediatric patients. Treatment options are difficult to assess through clinical trials, given the rarity of the disorder and its tendency for spontaneous remission. Case reports and case series are therefore the primary means of assessment. Because of the heterogeneity of the disease, there is no universal approach to treatment, and multiple agents may need to be trialed to achieve disease control. At present, topicals are used for most pediatric patients, though monotherapy with topicals is only effective for less severe disease. Despite concerns over their side-effect profiles, oral retinoids are generally accepted as a first-line systemic therapy. However, interleukin-17 inhibitors and ustekinumab, an interleukin-12 and interleukin-23 inhibitor, may soon become first-line systemic treatment as well, given their efficacy and relative safety in trials thus far. Ustekinumab, in particular, is emerging as a first-line agent for patients with pityriasis rubra pilaris with CARD14 gene variations. When these therapies fail, second-line and adjunctive therapies to consider include tumor necrosis factor-alpha inhibitors, methotrexate, and phototherapy. However, further investigation is necessary to assess the safety and efficacy of many of these agents in juvenile pityriasis rubra pilaris.

Pityriasis rubra pilaris partially responsive to treatment with upadacitinib: A case report

Pityriasis rubra pilaris is a rare inflammatory dermatosis characterized by orange-red confluent plaques, hyperkeratotic follicular papules, palmoplantar keratoderma, and, in some cases, erythroderma. The etiology of pityriasis rubra pilaris is unclear. This condition is often treated with oral retinoids and topical corticosteroids, and more recently, biological agents have become the mainstay of treatment. However, there is a paucity of high-quality evidence on the safety and effectiveness of these agents, and the disease often remains refractory to therapy. Herein, we present a case of pityriasis rubra pilaris with a favorable response to treatment with upadacitinib, a Janus kinase inhibitor, which has not been previously reported in the literature for the management of this condition.

Anti-interleukin-17A for pityriasis rubra pilaris: catching the psoriasis biologic wave

Linked Article: Boudreaux et al. Br J Dermatol 2022; 187:650–658.

Secukinumab for the treatment of adult-onset pityriasis rubra pilaris: a single-arm clinical trial with transcriptomic analysis

BACKGROUND

The pathogenesis of pityriasis rubra pilaris (PRP) is not completely understood, but interleukin (IL)-17 has been shown to play a critical role. There are no reliable immunomodulatory agents to treat PRP. We conducted an open-label, single-arm clinical trial of secukinumab, a monoclonal antibody that inhibits IL-17A, for the treatment of PRP.

OBJECTIVES

To evaluate the clinical efficacy of secukinumab and define the transcriptomic landscape of PRP and its response to IL-17A blockade.

METHODS

Twelve patients with PRP were recruited for an open-label trial of secukinumab. Patients received a 24-week course of secukinumab. The primary endpoint was a ≥ 75% reduction in Psoriasis Area and Severity Index (PASI 75) from baseline to week 28. Secondary endpoints included PASI 90, change in Physician's Global Assessment (PGA), and change in Dermatology Life Quality Index (DLQI). RNA sequencing was performed on lesional and nonlesional skin biopsies obtained at baseline and week 2. Sample groups were compared to identify differential gene expression and pathway enrichment. This trial was registered with ClinicalTrials.gov: 'Cosentyx (secukinumab) for the treatment of adult onset pityriasis rubra pilaris' - NCT03342573.

RESULTS

At week 28, six of 11 patients (55%) achieved PASI 75, and three patients (27%) achieved PASI 90. PGA (P = 0.008) and DLQI scores (P = 0.010) showed significant improvement with treatment. No serious treatment-related adverse events were encountered. Treatment with secukinumab normalized transcriptional differences between lesional and nonlesional skin. Transcriptomic data from nonresponsive patients suggest that overactivity of innate immune pathways may be driving resistance to secukinumab.

CONCLUSIONS

Secukinumab appears to be an effective treatment for PRP and warrants further investigation. PRP is a transcriptionally heterogeneous disease, reflecting its variable response to therapy. Agents targeting other IL-17 isoforms and innate immune mediators should be considered for future clinical trials. What is already known about this topic? The pathogenesis of pityriasis rubra pilaris is incompletely understood. Successful treatment has been reported with a variety of immunomodulatory agents, but disease is often refractory to therapy. Interleukin (IL)-17 is thought to drive keratinocyte proliferation and vascular dysfunction in this disease. A previous trial demonstrated efficacy of the anti-IL-17A drug ixekizumab for pityriasis rubra pilaris. What does this study add? Herein we describe the findings of a clinical trial of secukinumab, an anti-IL-17A monoclonal antibody, for the treatment of pityriasis rubra pilaris. Secukinumab was effective in treating pityriasis rubra pilaris. Our transcriptomic data give new insight into the expressional changes that occur in response to secukinumab and suggest mechanisms of treatment resistance.

Clinical response of CARD14-associated papulosquamous eruption to an anti-interleukin-17A antibody

Here we present another family with CARD14-associated papulosquamous eruption, which is characterized by mutations in CARD14 and skin lesions resembling psoriasis and pityriasis rubra pilaris. We show beneficial therapeutic response to anti-IL17A treatment in one patient and performed immunomonitoring of our patient, exhibiting enhanced pSTAT3 levels in T cells before treatment, which normalized after treatment. Together, our data support the pathogenic role of IL-17A in this disease, which might have consequences for future treatment decisions in this rare condition.

Beyond plaque psoriasis - pathogenesis and treatment of other psoriasis phenotypes

PURPOSE OF REVIEW

Psoriasis vulgaris is the commonest presentation of psoriatic disease, but morphologic variants such as pustular psoriasis (PP) and a closely related disease, pityriasis rubra pilaris (PRP), have been known for a long time, have been associated with rheumatologic manifestations indistinguishable from psoriatic arthritis (PsA) that may go unrecognized, and often represent a therapeutic conundrum. There is recent evidence that underlying genetic and pathogenetic differences may provide the basis for newer therapeutic approaches.

RECENT FINDINGS

This narrative review highlights the clinical, genetic and pathogenetic characteristics of PP and PRP, their association with PsA and recent developments in their treatment, especially with biologic agents targeting IL-36 and other cytokines of pathogenic relevance.

SUMMARY

The clinical manifestations of PP and PRP are less well known to rheumatologists than those of psoriasis, and recent advances in our insight on their pathogenesis may eventually overcome the therapeutic difficulties faced by dermatologists and rheumatologists in the management of these diseases and their rheumatologic manifestations.

Ixekizumab successfully treated severe pityriasis rubra pilaris after COVID-19 vaccination

Pityriasis rubra pilaris is an inflammatory dermatologic disorder of unknown cause. We report a 67-year-old man with Pityriasis rubra pilaris might induced by COVID-19 vaccination. The patient developed the lesions after the first dose of vaccine and significantly aggravated after the second dose. He had poor effect and liver function impairment developed after acitretin used, but achieved satisfactory efficacy after replacement to ixekizumab, an interleukin-17A inhibitor.

Biologic Therapies for the Management of Cutaneous Findings in Genodermatoses: A Review

Genodermatoses are genetically inherited dermatologic conditions. The management of cutaneous findings in genodermatoses is challenging, and first-line therapies, such as steroids and/or retinoids, are often inadequate. In recent years, research on the molecular basis of genodermatoses has led to the use of biologic therapies for intractable disease. Here, we review the evidence regarding the use of available biologic therapies for the management of dermatologic findings in genodermatoses. Biologic therapies appear to be promising therapeutic options for several recalcitrant genodermatoses, especially those with underlying immune dysregulation. However, not all genodermatoses are amenable to biologic therapies, and some have been shown to paradoxically worsen under treatment. Biologic therapies offer a novel avenue to target refractory genodermatoses. However, evidence supporting the use of biologic therapies in the management of genodermatoses is mostly limited to case reports and case series. Further studies are warranted to determine the safety and efficacy of biologic therapies for the management of cutaneous findings in genodermatoses.

Phospholipase A2 enzymes represent a shared pathogenic pathway in psoriasis and pityriasis rubra pilaris

Altered epidermal differentiation along with increased keratinocyte proliferation is a characteristic feature of psoriasis and pityriasis rubra pilaris (PRP). However, despite this large degree of overlapping clinical and histologic features, the molecular signatures these skin disorders share are unknown. Using global transcriptomic profiling, we demonstrate that plaque psoriasis and PRP skin lesions have high overlap, with all differentially expressed genes in PRP relative to normal skin having complete overlap with those in psoriasis. The major common pathway shared between psoriasis and PRP involves the phospholipases PLA2G2F, PLA2G4D, and PLA2G4E, which were found to be primarily expressed in the epidermis. Gene silencing each of the 3 PLA2s led to reduction in immune responses and epidermal thickness both in vitro and in vivo in a mouse model of psoriasis, establishing their proinflammatory roles. Lipidomic analyses demonstrated that PLA2s affect mobilization of a phospholipid-eicosanoid pool, which is altered in psoriatic lesions and functions to promote immune responses in keratinocytes. Taken together, our results highlight the important role of PLA2s as regulators of epidermal barrier homeostasis and inflammation, identify PLA2s as a shared pathogenic mechanism between PRP and psoriasis, and as potential therapeutic targets for both diseases.

T-Cell‒Mediated Autoimmunity: Mechanisms and Future Directions

T cells are key drivers of autoimmunity in numerous noncommunicable inflammatory skin diseases by directly harming host tissue or through helping B cells in producing autoantibodies. Technological advances have contributed to identifying autoantigens, the Holy Grail of autoimmunity, in many inflammatory disorders of the skin. Novel therapeutic approaches such as chimeric (auto)antibody receptor T cells are a milestone on the way to finding individualized, well-tolerated, targeted therapies. This review summarizes the current knowledge on pathogenesis, immune response pattern‒related ontology, diagnostic approaches, and treatment options of autoimmune skin diseases.

Gastroenterological safety of IL-17 inhibitors: a systematic literature review

INTRODUCTION

Interleukin 17 is a proinflammatory cytokine considered to play a significant role in the immunopathogenesis of many chronic immune-mediated disorders. Interleukin 17 inhibitors provide an excellent treatment option for patients with psoriasis, psoriatic arthritis, or ankylosing spondylitis. However, Interleukin 17 inhibitors have been suspected of worsening or triggering new-onset inflammatory bowel disease.

AREAS COVERED

A literature search was conducted until March 2021 to investigate reporting prevalence, and characteristics of all gastroenterological adverse events in patients treated with Interleukin 17 inhibitors. One hundred and six clinical randomized trials were included, involving 40,053 patients. Inflammatory bowel disease cases were reported in 0.4% of patients exposed to Interleukin 17 inhibitors. The most frequent other gastrointestinal adverse events were diarrhea (2.5%), nausea or vomiting (0.7%), and gastroenteritis (0.2%). Sixty-one uncontrolled or retrospective studies were included, involving 16,791 patients. Sixty (0.36%) inflammatory bowel disease cases were reported, 0.6% of patients reported other gastrointestinal adverse events.

EXPERT OPINION

Interleukin 17 inhibitors are safe and effective in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis. Low incidence rate of developing new-onset inflammatory bowel disease or exacerbating preexisting inflammatory bowel disease with anti-IL-17 agents has been reported. Clinicians should be aware of the possibility of these concerns when considering this therapy.

A multicentre open-label study of apremilast in palmoplantar pustulosis (APLANTUS)

BACKGROUND

Palmoplantar pustulosis (PPP) is a chronic skin disease with painful erythematous scaly or crusty lesions and pustules on the palms and soles. Apremilast is a phosphodiesterase 4 inhibitor that has proven effective in the therapy of psoriasis, psoriatic arthritis and in oral ulcers associated with Behcet's disease.

OBJECTIVE

To explore the efficacy of apremilast in PPP.

METHODS

APLANTUS was a phase 2 single-arm multicentre study of apremilast in 21 subjects with moderate-to-severe PPP. Primary endpoint was the per cent change of the Palmoplantar Pustulosis Psoriasis Area and Severity Index (PPPASI) at week 20 compared to baseline.

RESULTS

20 weeks of oral treatment with apremilast in patients with moderate-to-severe PPP resulted in a significant decrease of the PPPASI with a median reduction of 57.1% (p < 0.001), and 61.9% of patients achieved at least a 50% improvement of the PPPASI relative to baseline. The total number of pustules per patient decreased significantly relative to baseline with 76.2% of patients achieving at least a 50% reduction in total pustules count at week 20. Improvement of PPP was also apparent in a significant decrease of the dermatologic life quality index (DLQI). The median DLQI score dropped from 8.5 at baseline to 2.0 at week 20 (p = 0.030). Apremilast was generally well tolerated, and no serious adverse events occurred.

CONCLUSIONS

Patients with PPP treated with apremilast showed benefit both in objective and subjective disease parameters. Apremilast should be investigated further in this difficult-to-treat skin condition. EudraCT number: 2016-005122-11.

The IL-23/IL-17 Pathway in Inflammatory Skin Diseases: From Bench to Bedside

Interleukin-17 (IL-17) is an essential proinflammatory cytokine, which is mainly secreted by the CD4⁺ helper T cells (Th17 cells) and subsets of innate lymphoid cells. IL-17A is associated with the pathogenesis of inflammatory diseases, including psoriasis, atopic dermatitis, hidradenitis suppurativa, alopecia areata, pityriasis rubra pilaris, pemphigus, and systemic sclerosis. Interleukin-23 (IL-23) plays a pivotal role in stimulating the production of IL-17 by activating the Th17 cells. The IL-23/IL-17 axis is an important pathway for targeted therapy for inflammatory diseases. Emerging evidence from clinical trials has shown that monoclonal antibodies against IL-23, IL-17, and tumor necrosis factor are effective in the treatment of patients with psoriasis, atopic dermatitis, hidradenitis suppurativa, pityriasis rubra pilaris, pemphigus, and systemic sclerosis. Here, we summarize the latest knowledge about the biology, signaling, and pathophysiological functions of the IL-23/IL-17 axis in inflammatory skin diseases. The currently available biologics targeting the axis is also discussed.

Secukinumab monotherapy successfully treated severe refractory type V (atypical juvenile) pityriasis rubra pilaris: A case report and literature review

Pityriasis rubra pilaris (PRP) is a rare heterogeneous group of papulosquamous inflammatory disorders with unknown etiology. PRP is often resistant to many conventional therapies which has made more challenging on treatment. More recently, several studies have shown encouraging clinical results of secukinumab in the treatment of PRP in adult, but no studies have explored its effects in children. We herein report a 7-year-old boy with severe type V PRP responded rapidly to secukinumab monotherapy (150 mg once weekly) when conventional therapies have failed. The patient showed rapid and dramatic improvement of erythema, palmoplantar hyperkeratosis, scaling, and itching within only 5 weeks, with no adverse effects. Secukinumab could be considered as a treatment option for refractory PRP in children, as recently reported in adult.