A case of classic adult pityriasis rubra pilaris successfully treated with a combination of acitretin and ustekinumab: A case report

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.

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.

Misdiagnosed Pityriasis Rubra Pilaris Successfully Managed With Isotretinoin: A Case Series

Being a rare inflammatory, hyperproliferative dermatosis, diagnosing pityriasis rubra pilaris (PRP) can be a challenge to many clinicians. Our case reports aim to demonstrate that PRP is frequently diagnosed and managed as atopic dermatitis (AD) and that distinguishing features on dermoscopy, and biopsy can help diagnose this rare disease. The study also aims to show that PRP can be successfully treated with Isotretinoin. Our case series aims to describe two cases of PRP, initially diagnosed as AD and managed with topical corticosteroids. Being the first case series in the literature to describe the incidences of diagnosing PRP as AD portrays the significance of utilizing dermoscopy and biopsy as tools to confirm this diagnosis for appropriate management. Although PRP is a rare diagnosis, dermoscopy and biopsy can help confirm the disease. Management with isotretinoin will most likely have successful outcomes in those patients.