Case of pityriasis rubra pilaris progressed to generalized erythroderma following blockade of interleukin-17A, but improved after blockade of interleukin-12/23 p40

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.

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.

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.

Off-label uses of ustekinumab

Ustekinumab (brand name Stelara®) is a human interleukin-12 and -23 antagonist and has been indicated for the treatments of moderate to severe plaque psoriasis, psoriatic arthritis, Crohn's disease and ulcerative colitis. This review aims to synthesize and interpret the literature evaluating the off-label uses of ustekinumab. We performed searches in PubMed and ClinicalTrials.gov for clinical trials, observational studies, case series, and case reports evaluating label uses of ustekinumab. Studies evaluated the efficacy of ustekinumab for the following conditions: other types of psoriasis (expect plaque psoriasis and psoriatic arthritis), pityriasis rubra pilaris, hidradenitis suppurativa, atopic dermatitis, pyoderma gangrenosum, et al. Based on the available literature, ustekinumab appears to be a potential treatment choice for many other diseases. However, more clinical trials data are needed to adequately assess the safety and efficacy of ustekinumab for the treatment of these conditions.

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.

Successful treatment with cyclosporine and guselkumab for pityriasis rubra pilaris

A man with pityriasis rubra pilaris (PRP) showed no improvement in skin symptoms despite treatment with several drugs. The patient was diagnosed as having type 1 PRP. Combination therapy with cyclosporine and guselkumab improved his skin condition. Here, we propose a novel therapeutic strategy for intractable PRP.

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.

Alternative uses of ustekinumab for non-indicated dermatological conditions: a systematic review

Ustekinumab is approved for the treatment of psoriasis and Crohn's disease. Because many dermatological conditions are due to immune-mediated development, ustekinumab may be effective in other conditions. A systematic review of the off-label uses of ustekinumab, as well as on-label adverse effect, was performed, reporting on clinical improvement. MEDLINE, Embase, Web of Science, and Cochrane databases were searched for studies regarding ustekinumab treatment of rativa (HS), lichen planus (LP), pyoderma gangrenosum (PG), pityriasis rubra pilaris (PRP), cutalopecia areata (AA), atopic dermatitis (AD), Bechet's disease, bullous pemphigoid (BP), hidradenitis suppuaneous sarcoidosis, cutaneous systemic lupus erythematosus (SLE), and vitiligo. Descriptive statistics were performed. 74 articles of 4596 screened were included, and reported on 212 patients receiving ustekinumab treatment. Across all studies, ustekinumab showed promise in treating patients: AA (10/12 patients; 83.3% improvement), AD (28/74 patients; 37.8% improvement), HS (42/52 patients; 80.8% improvement), and PRP (25/27 patients; 92.6% improvement), among others. Adverse events were noted with the use of ustekinumab, including development of AA (four patients), AD (three patients), and BP (four patients), among others. Ustekinumab can be a promising option for patients with dermatological conditions refractory to traditional therapies. Adverse events must be monitored in certain patients.

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.

Erythrodermic pityriasis rubra pilaris treatment: Two case reports and literature review

Pityriasis rubra pilaris (PRP) is a rare inflammatory dermatosis characterized by hyperkeratotic follicular papules and erythematous-desquamative plaques that tend to progressively evolve into erythroderma. Treatment is challenging given that international guidelines are not available and large-scale trials do not exist. Traditionally, many topical and systemic drugs had been used as consolidated agents; recently, biologicals are gaining increasing importance, promisingly dominating the therapeutic scenario ahead. Herein, we present a case series showing the "past" and the "future" therapeutic approaches to erythrodermic PRP, one case treated with acitretin and nb-UVB phototherapy combination, while the other with ustekinumab, performing also a throughout literature review.

Learning From Success and Failure: Biologics for Non-approved Skin Diseases

The impressive potential of biologics has been demonstrated in psoriasis, hidradenitis suppurativa, and urticaria. Numerous biologicals are entering the field for a restricted number of skin disorders. Off-label use of biologics in other recalcitrant skin diseases has increased. Mounting data point to the potential of already existing biologics acting on the IL-17/IL-23 pathway in skin disorders with epidermal hyperkeratosis (e.g., pityriasis rubra pilaris), acneiform inflammation (e.g., hidradenitis suppurativa), and loss of mucosal integrity (e.g., aphthosis). TNF-α blockers are also effective in the latter conditions but seem of particular value in granulomatous (e.g., granuloma annulare) and neutrophilic disorders (e.g., pyoderma gangrenosum). Failure of IL-17 blockade in skin diseases resulting from immune-mediated cell destruction (e.g., alopecia areata and vitiligo) illustrates its limited involvement in Th1-dependent skin immunology. Overall, disappointing results of TNF-α blockers in alopecia areata and vitiligo point to the same conclusion although promising results in toxic epidermal necrolysis suggest TNF-α exerts at least some in vivo Th1-related activities. Acting on both the Th1 and Th17 pathway, ustekinumab has a rather broad potential with interesting results in lupus and alopecia areata. The efficacy of omalizumab in bullous pemphigoid has revealed an IgE-mediated recruitment of eosinophils leading to bullae formation. Reconsidering reimbursement criteria for less common but severe diseases seems appropriate if substantial evidence is available (e.g., pityriasis rubra pilaris). For other disorders, investigator- and industry-initiated randomized clinical trials should be stimulated. They are likely to improve patient outcome and advance our understanding of challenging skin disorders.