Updates on Pityriasis Rubra Pilaris: A Scoping Review.

Pityriasis rubra pilaris (PRP) is a rare, inflammatory papulosquamous skin disease with unknown exact etiology. Historically, PRP has been challenging to diagnose, especially during the acute phase, and to treat, due to its unclear pathogenesis. To better inform clinical practice, a literature review was conducted employing a broad search strategy to capture PRP-related published studies between January 1, 2012 to October 31, 2022. Two hundred twenty-one studies were identified, which were categorized into 9 themes: (1) potential causes and triggering factors, (2) comorbidities, (3) diagnostic difficulties, (4) genetics, (5) clinical manifestations and laboratory values, (6) treatment, (7) treatment-related adverse events, (8) quality of life, and (9) other. COVID-19 infection, COVID-19 vaccination, and malignancy were the most commonly reported potential triggering factors. Misdiagnosis is very common during the early acute stages. Pathogenesis and genetic studies have further implicated caspase recruitment domain family member 14 (CARD14) mutations in the development of familial PRP (Type V) and have underlined the overlap between psoriasis and PRP. To date, there are currently no specific and validated scoring systems or tools to assess the severity of PRP. While large, randomized trials are still lacking, biologic agents remain the most effective therapy.

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.

Pityriasis rubra pilaris type IV-associated arthritis treated with adalimumab.

Pityriasis rubra pilaris (PRP) is a very rare disease from the hyperkeratotic papulosquamous disorder group. The rheumatologic manifestations of PRP are extremely rare and less known to clinicians than those of psoriasis. An interesting case of inflammatory arthritis in the hand of an adolescent patient who was successfully treated with adalimumab and compatible with the diagnosis of type IV circumscribed juvenile PRP is presented in the light of the literature.

A novel mutation in a CARD14-associated papulosquamous eruption.

CARD14-associated papulosquamous eruption (CAPE), a spectrum that includes clinical features of psoriasis and pityriasis rubra pilaris (PRP), is associated with activating mutations in the CARD14 gene. Herein we describe the clinical features of a family with CAPE and a novel mutation of CARD14, and highlight ectropion as part of the phenotypic spectrum of CAPE.

Pityriasis rubra pilaris heralding diagnosis of urothelial carcinoma: a case report.

Pityriasis rubra pilaris is a papulosquamous inflammatory dermatosis that can be associated with HIV, autoimmunity, infections, certain medications, and neoplasms. Paraneoplastic pityriasis rubra pilaris has previously been reported in association with solid organ malignancies and once with leukemia. Herein, we present an elderly man with paraneoplastic pityriasis rubra pilaris, heralding the diagnosis of low-grade papillary urothelial carcinoma. Our patient's pityriasis rubra pilaris resolved after surgical resection of the tumor.

Successful treatment with ustekinumab in CARD14-associated papulosquamous eruption in a Brazilian child.

CARD14-associated papulosquamous eruption (CAPE) was proposed in 2018 to describe the clinical features of psoriasis and pityriasis rubra pilaris with CARD 14 mutations. We report a 5-month-old female infant who developed CAPE-associated erythroderma. Although she did not respond to conventional therapies, she responded well to ustekinumab treatment at the age of 4 years.

Early Presentation of Pityriasis Rubra Pilaris Mimicking Tinea Corporis: Diagnostic Challenges of a Rare Skin Condition.

BACKGROUND Pityriasis rubra pilaris (PRP) is a rare chronic inflammatory skin condition characterized by follicular, papulosquamous, reddish-orange scaling, palmoplantar keratoderma, and erythema with islands of sparing. Its heterogeneous clinical presentation makes the diagnosis of PRP quite challenging, especially at the initial presentation, as it can mimic common skin conditions. CASE REPORT We present a case with an early presentation of PRP in a 61-year-old Malay woman with underlying uncontrolled diabetes, and discuss evolving clinical course of her disease. She presented to a primary care clinic with a 3-week history of itchy, ring-like skin lesions that started on her neck and chest but subsequently spread widely on her chest, back, and upper extremities. She was first treated as having extensive tinea corporis but responded poorly to multiple courses of antifungal treatment. An initial skin biopsy that was taken at the dermatology clinic revealed features suggestive of erythema annulare centrifugum. However, despite topical steroid treatment, her skin condition evolved further and she developed generalized erythroderma along with follicular hyperkeratosis and palmoplantar keratoderma. A repeat biopsy finally confirmed the diagnosis of PRP. CONCLUSIONS Making the diagnosis of PRP is challenging for clinicians. However, clinicians should approach any common skin problem that does not respond to treatment appropriately, with consideration of other uncommon skin disorders. A repeat skin biopsy may be considered if there are any doubts about the diagnosis. A clinical and histopathological correlation is important to aid in the diagnosis of PRP.

Pityriasis rubra pilaris with erythema gyratum repens-like eruption and resolution with ustekinumab.

Erythema gyratum repens (EGR) is a rare paraneoplastic disorder often preceding the diagnosis of underlying malignancy by 9 months on average, while pityriasis rubra pilaris (PRP) is an uncommon papulosquamous inflammatory disease. We present the case of a 58-year-old woman with an EGR-like eruption transforming from resolving PRP, without associated malignancy. Her rash dramatically resolved within a month of ustekinumab initiation, which supports this presentation as a unique entity.

Successful treatment of a child's pityriasis rubra pilaris (PRP) with ustekinumab and acitretin.

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disease that occurs with phenotypic variability in adults of all ages as well as in children. Data on the treatment of PRP is limited. Here, we report a 5-year-old girl with widespread skin involvement and prominent palmoplantar hyperkeratosis who was initially treated for psoriasis. After reevaluation, a diagnosis of PRP was made, and the patient had an excellent therapeutic response to ustekinumab and acitretin.

Paraneoplastic Pityriasis Rubra Pilaris Preceding Leukemia.

ABSTRACT: Pityriasis rubra pilaris (PRP) is a rare, chronic papulosquamous disorder that presents with scaling plaques, palmoplantar keratoderma, and keratotic follicular papules. Typically, there are distinctive unaffected areas referred to as "islands of sparing." Pityriasis rubra pilaris has been associated with various immunodeficient states and malignancies.The authors conducted a literature review using MEDLINE, PubMed, and Google Scholar, documenting all known cases of PRP associated with malignancy; 15 cases were found in the literature. They also present the case of a 49-year-old White man who, prior to referral to dermatology, was seen in urgent care for widespread pruritic rash. Physical examination in the dermatology clinic revealed confluent, scaly erythematous papules coalescing into plaques with island of sparing involving the trunk and upper and lower extremities. Bilateral palms and soles showed hyperkeratosis with fissuring. He was diagnosed with PRP after punch biopsy and began a new course of topical corticosteroid therapy. Hematology was consulted because of abnormal complete blood count results, and he was subsequently diagnosed with chronic lymphoid leukemia.Treatment of PRP is largely based on clinical experience and may involve corticosteroids, immunomodulators, or biologic therapy. The relationship between PRP and malignancy is unknown. Current theories postulate it may be driven by tumor production of functional peptides or antigen cross-reactivity between cancer cells and the skin. This is the second reported case of PRP as a manifestation of leukemia, and the first of chronic lymphoid leukemia. Although not yet understood, the documented relationship between PRP and malignancy prompts screening for cancer in all patients with new-onset PRP.