A case of juvenile pityriasis rubra pilaris type III successfully treated with etanercept

Biologics for Treatment of Pityriasis Rubra Pilaris: A Literature Review

OBJECTIVE

To describe the published efficacy and adverse event rates associated with existing biologics for the treatment of pityriasis rubra pilaris (PRP).

DATA SOURCES

A literature review using the PubMed database (January 1990-July 2023) was conducted. Multiple search combinations were conducted using "pityriasis rubra pilaris" and various biologics as keywords to identify relevant articles.

STUDY SELECTION AND DATA EXTRACTION

Inclusion criteria included all study types that were published within the past 30 years in English and mentioned at least one biologic and PRP. A preliminary search yielded a total of 499 results. After screening using inclusion and exclusion criteria, 77 relevant articles (69 case reports, 5 case series, 2 clinical trials, and 1 retrospective analysis) were analyzed.

DATA SYNTHESIS

TNF-α inhibitors have been evaluated and are effective in treating PRP. However, recent treatment with anti-interleukin (IL)-17 and anti-IL-23 therapies such as ustekinumab, secukinumab, and ixekizumab are emerging as new treatment options with a mean improvement in PRP Area and Severity Index scores, change in severity of erythema, scaling, and thickness of PRP lesions. From initial clinical trials, secukinumab and ixekizumab are promising treatment options for achieving remission.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review compares the efficacy for numerous biologics and a discussion to guide clinicians on benefits and risks in choosing a biologic for PRP patients.

CONCLUSIONS

Biologics may be a favourable treatment option leading to greater patient adherence due to reduced dosing frequencies, improvement in quality of life, and reduction in frequency and severity of flares.

Successful Treatment of Pityriasis Rubra Pilaris with Risankizumab in Children

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disease that affects men and women of all ages, including children. PRP is characterized by follicular and palmoplantar hyperkeratosis and salmon-colored scaling plaques. The exact pathogenesis of PRP is still unknown; most PRP cases are acquired, but some cases may show a familial occurrence, often associated with a mutation in the CARD14 gene. Due to the rarity of PRP, treatment recommendations are based mainly on case reports, small case series and expert opinions and still represent a major therapeutic challenge, especially in children. A growing number of reports on treatment with biologicals, particularly anti-TNFα, has been published. However, an involvement of the IL-23/Th17 axis in both psoriasis and PRP pathogenesis may suggest that this pathway may be a potential therapeutic target. Here, we present three pediatric patients with PRP successfully treated with risankizumab. All patients exhibited a severe course of PRP and lack of response to conventional therapy, including acitretin, cyclosporine and phototherapy. A single dose of 75 mg risankizumab resulted in almost complete clearance of skin lesions in case 1 and 2 at week 4. In patient 3, clear skin was achieved after the second administration of risankizumab (150 mg). All patients continue the treatment with risankizumab, and no adverse effects have been reported up to the present time. Our study demonstrates that risankizumab, an IL-23 blocker, shows good efficacy and safety among pediatric patients with PRP.

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.

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

Importance

Pityriasis rubra pilaris is a rare and disabling cutaneous disease that is frequently recalcitrant to conventional therapies and appears to involve interleukin (IL)-17 overexpression.

Objective

To investigate the clinical response and safety of ixekizumab in treating pityriasis rubra pilaris.

Design, Setting, and Participants

Single-arm, investigator-initiated trial conducted in adult patients with moderate to severe pityriasis rubra pilaris at a single-center academic university from June 2018 to January 2020. A total of 41 patients were screened, 12 were enrolled, and 11 completed the full duration of therapy. A referred, consecutive sample was used during participant selection. The treatment period and primary outcome occurred over 24 weeks with additional patient follow-up through 36 weeks.

Intervention

Subcutaneous administration of ixekizumab, a humanized IgG4 antibody that binds IL-17A, at the US Food and Drug Administration-approved dosing schedule for treatment of psoriasis for 24 weeks.

Main Outcomes and Measures

The primary outcome was the mean change in Psoriasis Area and Severity Index at 24 weeks. Secondary outcomes included change in affected body surface area, quality of life, induction of sustained remission, and association of improvement with CARD14 genetic variations and cutaneous cytokine expression.

Results

A total of 12 white patients (mean [SD] age, 49.8 [15.1] years; 8 male [67%]) were enrolled between June 2018 and April 2019, with 11 completing the full course of intervention. The mean (SEM) improvements in Psoriasis Area and Severity Index, affected body surface area, and Dermatology Life Quality Index were 15.2 (2.1) (P < .0001), 29.8% (9.3%) (P = .009), and 9.5 (2.5) (P = .004), respectively. The 4 participants with the most improvement in Psoriasis Area and Severity Index at week 24 stayed in remission at week 36 (defined as lack of increase in Psoriasis Area and Severity Index from week 24 through week 36), off therapy. Relative dermal IL-17A expression decreased by a 1.9 log-fold change. No participants had known pathogenic CARD14 variations. There were no serious adverse events.

Conclusions and Relevance

In this single-armed trial, ixekizumab was associated with reduced clinical signs and symptoms of pityriasis rubra pilaris in a subset of patients, including those in whom other systemic therapies have failed.

Trial Registration

ClinicalTrials.gov Identifier: NCT03485976.