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 After Moderna COVID-19 Vaccination: A Case Report and Literature Review.

ABSTRACT: To date, over 60% of the world's population has received at least 1 dose of coronavirus disease 2019 (COVID-19) vaccination, with over 12 billion doses administered globally. Commonly reported adverse effects of COVID-19 vaccination include fever, headache, myalgia, and injection site reactions. The spectrum of documented cutaneous reactions after COVID-19 vaccination is broad; however, pityriasis rubra pilaris (PRP) or PRP-like eruption secondary to COVID-19 vaccine is exceedingly rare, with only 17 cases previously reported to date in the English literature. In this article, we describe an additional case of COVID-19 vaccination-associated PRP in a 50-year-old woman with a history of metastatic breast carcinoma, who developed a widespread cutaneous eruption characteristic of PRP, including palmoplantar keratoderma, 10 days after her third dose of Moderna COVID-19 vaccine. Punch biopsy specimen showed epidermal hyperplasia with overlying hyperkeratosis, alternating orthokeratosis and parakeratosis and focal follicular plugging, supporting the diagnosis of PRP. The patient improved within weeks of initiating oral acitretin and topical steroids, with resolution achieved after 3 months of continued therapy. To the best of our knowledge, this is the third reported case of Moderna COVID-19 vaccination-associated PRP and collectively the 18 th after the administration of all COVID-19 vaccines currently available, including Pfizer-BioNTech, and AstraZeneca.

Pityriasis rubra pilaris post-infection due COVID-19: case report.

CASE DESCRIPTION: 32-month-old boy, IgG positive for SARS-CoV-2, presented to the emergency department with dermatologic lesions. CLINICAL FINDINGS: Four days before admission, he presented skin eruptions with redness and pruritus on hands and feet. Generalized papular erythema was evidenced, upper extremities with diffuse erythematosquamous plaques, palmoplantar keratoderma, so he was evaluated by a dermatologist who diagnosed pityriasis rubra pilaris. TREATMENT AND OUTCOME: rehydrating cream, cetirizine 0.5 mg/kg/day every two days, and prednisolone 2 mg/kg/day in the morning. He was discharged after 14 days, the patient presented clinical improvement, but the erythematous lesion persisted on the trunk and extremities. In the evaluation, after three months, the patient did not show the described lesions, evidencing an improvement and clinical resolution of the dermatological problems. CLINICAL RELEVANCE: We report a patient with pityriasis rubra piloris associated with a post-infection by SARS-CoV-2 that had not been described before.

Pityriasis rubra pilaris post-infection due COVID-19: case report / Pitiriasis rubra pilaris post-infección por COVID-19: reporte de un caso

Abstract Case description: 32-month-old boy, IgG positive for SARS-CoV-2, presented to the emergency department with dermatologic lesions. Clinical findings: Four days before admission, he presented skin eruptions with redness and pruritus on hands and feet. Generalized papular erythema was evidenced, upper extremities with diffuse erythematosquamous plaques, palmoplantar keratoderma, so he was evaluated by a dermatologist who diagnosed pityriasis rubra pilaris. Treatment and outcome: rehydrating cream, cetirizine 0.5 mg/kg/day every two days, and prednisolone 2 mg/kg/day in the morning. He was discharged after 14 days, the patient presented clinical improvement, but the erythematous lesion persisted on the trunk and extremities. In the evaluation, after three months, the patient did not show the described lesions, evidencing an improvement and clinical resolution of the dermatological problems. Clinical relevance: We report a patient with pityriasis rubra piloris associated with a post-infection by SARS-CoV-2 that had not been described before.

Resumen Descripción del caso: Niño 32 meses de vida, con IgG positivo para SARS-CoV-2, acude al servicio de emergencia por presentar lesiones dermatológicas. Hallazgos clínicos: Cuatro días antes del ingreso presentó erupciones en la piel, con enrojecimiento y prurito en manos y pies. Se evidenció eritema papular generalizado, extremidades superiores con placas eritematoescamosas difusas, queratodermia palmo-plantar por lo que es evaluado por dermatólogo quien diagnostica pitiriasis rubra pilaris. Tratamiento y resultado: Crema rehidratantes, cetirizina 0.5 mg/kg/día cada 2 días y prednisolona 2 mg/kg/día por la mañana. Fue dado de alta a los 14 días, el paciente presenta mejora clínica, pero aún persiste la lesión eritematosa en tronco y extremidades. En la evaluación a los tres meses el paciente no mostró las lesiones descritas, evidenciando una mejoría y resolución clínica de los problemas dermatológicos. Relevancia clínica: Se reporta un paciente con afectación por pitiriasis rubra piloris asociado a una post-infección por SARS-CoV-2 que no se había descrito antes.

Pityriasis rubra pilaris as a systemic disease.

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disorder of unknown etiology, initially described in 1835. It is characterized by keratotic follicular papules, well-demarcated salmon-colored erythematous scaly plaques interspersed with distinct islands of uninvolved skin, and palmoplantar keratoderma. Is PRP a systemic disease? Skin is mainly affected in PRP. Despite its clinical heterogeneity, PRP could be associated with a variety of rheumatologic, infectious, neoplastic, and other extracutaneous manifestations. We accept the hypothesis of not only an association but also a causative relation between skin and systemic manifestations with possible common underlying pathomechanisms such as systemic immunologic processes and superantigen mimicry.

Circumscribed Juvenile Pityriasis Rubra Pilaris (Type 4) Koebnerising after a Hot Water Burn: Mild Disease with Maximum Koebner Response.

Dear Editor, Pityriasis rubra pilaris (PRP) is a chronic, inflammatory, papulosquamous skin disorder that is characterized by follicular hyperkeratosis and reddish-orange, scaling dermatitis with islands of normal skin (1,2). PRP is classified into 5 groups based on clinical features. Type 4 PRP is characterized by well-demarcated, hyperkeratotic erythematous plaques localized on the elbows and knees with palmoplantar keratoderma (1,2). An 8-year-old girl presented to our clinic with erythematous plaques on both elbows, the legs, and the knees. Plantar keratoderma was noticed on clinical examination. The lesions had started on the elbows and knees about a year ago. The lesions on the leg were surrounded by an irregular, hyperpigmented border. On close inspection, the plaques were formed by follicular papules and mild desquamation was noticed. Upon questioning, it was learned that the lesions on the leg with hyperpigmented borders had emerged after a hot water burn three months ago and that they were localized exactly on the burned areas of the skin (Figure 1). A biopsy was performed on the new lesions, and histopathological evaluation revealed parakeratosis with alternating orthokeratosis, irregular hyperkeratosis, keratotic plugs, and a mild perivascular lymphocytic infiltration around the blood vessels (Figure 2). A diagnosis of PRP was established. The Koebner phenomenon (KP) is described as the development of lesions in previously normal skin after exposure to internal or external trauma such as surgical incisions, burns, friction, insect bites, and allergic and irritant reactions (3). The pathogenesis of KP is not fully understood, but epidermal cell injury and dermal inflammation have been proposed as having a role in the pathophysiology (4). Experimental studies on the mechanism of KP have been performed mostly on patients with psoriasis (3). Disease severity, early age of disease onset, and multiple previous therapies have been found to be associated with KP (5,6). KP has previously been reported after injury with the sharp end of a stick in type 3 PRP, a generalized PRP form (7). However, our patient was diagnosed with type 4 PRP, which is a localized form of the disorder. Griffiths reported type 4 PRP does not evolve to generalized forms (8). In this respect, our case was interesting as maximum Koebner response was observed despite the mild PRP. We therefore believe that disease severity is not a determining factor in KP and that the severity of skin damage plays a crucial role. We also think that changes in the cytokine milieu in the burn area may be responsible for KP, as levels of IL-17 and IL-22, which have been shown to be upregulated in burns, also play a role in PRP pathogenesis (9,10). The disease onset at an early age might have also had a contributing role in the Koebner response in this patient. The hyperpigmented borders of the Koebnerized plaques were also notable as they were spared from KP. Some spared areas were also seen within the Koebnerized plaques themselves. A threshold level of trauma is thought to be necessary for inducing KP (3). The clinical picture of our patient may indicate that the skin damage was much less severe in some areas of the burn, especially in the periphery, and that KP was therefore not observed in these areas. Our case clearly demonstrates that the Koebner response is not related to disease severity. We believe that the type of trauma is an important factor in determining the severity of skin damage and the changes in the cytokine milieu in the involved skin. Early disease onset also seems to contribute to the development of KP. Further studies investigating the mechanism of KP in various skin disorders are necessary. As far as we are aware, this is the first case reporting Koebnerization in the circumscribed juvenile form of PRP.

A Review on Pityriasis Rubra Pilaris.

Pityriasis rubra pilaris (PRP) is an idiopathic, papulosquamous inflammatory dermatosis. It is characterized by hyperkeratotic follicular papules coalescing into orange-red scaly plaques, islands of sparing, and palmoplantar keratoderma. PRP can be subdivided into six clinical subtypes according to Griffiths' classification, based on age of onset, disease extent, prognosis, and other associated features. The sixth subtype of PRP occurs in individuals affected by HIV infection, and retroviral screening in all de novo cases of PRP is advised. Other reported associations include various infections, autoimmunity, drugs, and malignancies, although the true significance of these is still unclear. The genetic basis for familial cases, most commonly categorized under the fifth subtype, has been mapped to gain of function mutations in the caspase recruitment domain family, member 14 (CARD14) gene. Treatment of PRP remains a challenge to this day due to a paucity of high-quality evidence. Therapeutic regimens have been guided mostly by case reports and case series, with the mainstay of treatment being oral retinoids. Recently, biologics have emerged as a promising treatment for PRP. We present a review of the clinicopathologic features, pathogenesis, associated disorders, and treatment of PRP, with an emphasis and critical appraisal of the existing literature on the latter.

Pityriasis rubra pilaris: algorithms for diagnosis and treatment.

Pityriasis rubra pilaris (PRP) is a rare inflammatory skin disease that affects men and women of all ages and also children. The clinical appearance of PRP is highly variable, as is the individual prognosis. Therefore, stratifying PRP into six disease subtypes represents a first step to personalized medicine for this rare inflammatory skin disease. The next step should be to associate specific therapeutic strategies with these subtypes of PRP. However, no randomized, controlled trials on the treatment of PRP have been performed. Consequently, the actual treatment algorithm for PRP will be based on clinical experience, small case series and case reports. The majority of published evidence is on type I PRP, whereas the treatment experience for other clinical types of PRP is still sparse and has to be gained. Nevertheless, it is now time to start developing valid algorithms as a basis for the diagnosis and treatment of PRP based on the data available. This review makes use of algorithms developed in psoriasis and atopic eczema and puts together recent insights into the pathogenesis, diagnosis and treatment experience of PRP. The innovative intention of this appraisal is to develop a structured algorithm for PRP treatment that should be further developed going forward.

Paraneoplastic pityriasis rubra pilaris: case report and literature review.

Pityriasis rubra pilaris (PRP; MIM 173200) is an uncommon papulosquamous inflammatory dermatosis. Only a few cases of PRP associated with an underlying malignancy have been documented. We investigated a 59-year-old patient presenting with a fulminant form of PRP recalcitrant to systemic retinoid therapy, in whom the skin disease heralded a diagnosis of cholangiocarcinoma. We searched the MEDLINE database to find articles reporting on similar associations of PRP with malignancies. We identified 10 studies linking PRP and malignancies, but an association between PRP and cholangiocarcinoma has not yet been reported.

[Pityriasis rubra pilaris]. / Pityriasis rubra pilaire: une dermatose mal connue.

Pityriasis rubra pilaris is a rare heterogeneous disorder characterized by follicular keratosis, perifollicular erythema and palmoplantar hyperkeratosis. The aetiology is still unknown. In the majority of cases some triggering factors are found such as trauma or bacterial infection, possibly on a predisposed condition. In other cases, some immunological disorders are associated, and in familial cases a genetic disorder of keratinization has been suggested. The evolution is variable according to the clinical type. The treatment is not well defined, and there is a lack of clinical trials. The best results however are obtained with oral retinoids, methotrexate or ciclosporine as alternative therapy. New TNF inhibitors and anti-IL-12/23 showed a good result and could be have interest in the future.

Severe, Disfiguring, Pityriasis Rubra Pilaris in a Woman in the Dominican Republic: Histopathologic Diagnosis and Response to Antiretroviral Therapy.

Pityriasis rubra pilaris (PRP) is a poorly understood dermatologic condition usually accompanied by keratoderma and intense erythroderma with islands of unaffected skin. The PRP categories include HIV-associated PRP VI. A 23-year-old HIV-infected, dark-skinned woman in the Dominican Republic developed an extremely severe, disfiguring process characterized first by a dry scaly rash involving her face, trunk, and extremities with hyperpigmentation and islands of spared skin and minimal erythroderma, followed by alopecia and development of a thick horny layer on the scalp and face. The condition, histologically proven to be PRP, was accompanied by fever, wasting, and decline in CD4 count. Initiation of combination antiretroviral therapy (cART) was followed by rapid and sustained resolution of PRP. Nine years after ART initiation, she remains well, with viral suppression and immune recovery, without PRP recurrence but with sparse hair regrowth and facial scarring. In some dark-skinned patients, severe PRP may not feature characteristic erythroderma but will respond to combination ART.

Pityriasis Rubra Pilar and hypothyroidism.

Pityriasis Rubra Pilaris (PRP) is a chronic and rare papulosquamous disorder. Treatment of Pityriasis Rubra Pilaris is based on empiric evidence because of several doubts regarding its etiology and also because of its relative rarity, making randomized studies difficult to perform. Some factors suggest that the metabolism of vitamin A is involved in pathogenesis. We report a case of Pityriasis Rubra Pilaris associated with autoimmune hypothyroidism which presented rapid and complete response after thyroid hormone replacement, without any association with other systemic treatment. In literature there are only three other reports of significant improvement of the lesions after hormonal correction. Deficiency of thyroid hormone inhibits the conversion of carotene into vitamin A, which would be responsible for the occurrence of Pityriasis Rubra Pilaris in this patient.

Pityriasis Rubra Pilar and hypothyroidism

Pityriasis Rubra Pilaris (PRP) is a chronic and rare papulosquamous disorder. Treatment of Pityriasis Rubra Pilaris is based on empiric evidence because of several doubts regarding its etiology and also because of its relative rarity, making randomized studies difficult to perform. Some factors suggest that the metabolism of vitamin A is involved in pathogenesis. We report a case of Pityriasis Rubra Pilaris associated with autoimmune hypothyroidism which presented rapid and complete response after thyroid hormone replacement, without any association with other systemic treatment. In literature there are only three other reports of significant improvement of the lesions after hormonal correction. Deficiency of thyroid hormone inhibits the conversion of carotene into vitamin A, which would be responsible for the occurrence of Pityriasis Rubra Pilaris in this patient.

Paraneoplastic pityriasis rubra pilaris as the presenting manifestation of metastatic squamous cell carcinoma.

Pityriasis rubra pilaris (PRP) is a rare idiopathic papulosquamous eruption. Few cases of PRP have been reported in association with malignancies. We report a case of an 83-year-old Caucasian male who presented with recalcitrant paraneoplastic PRP as the presenting manifestation of metastatic squamous cell carcinoma with unknown primary. Treatment with chemotherapy and radiation led to temporary radiologic and symptomatic regression of the cancer as well as resolution of cutaneous findings. This suggests a direct relationship between the PRP and the underlying malignancy in this patient. This case highlights a rare, but important phenomenon in which PRP may act as a harbinger for underlying malignancy.

Letter: Adenocarcinoma of the lung associated with pityriasis rubra pilaris.

We describe a case of pityriasis rubra pilaris refractory to conventional treatment, found to be associated with an unrecognized primary adenocarcinoma of the lung. Complete resolution of the eruption followed surgical resection of the tumor.

[Pityriasis rubra pilaris after vaccination]. / Pityriasis rubra pilaire après vaccination.

BACKGROUND: Pityriasis rubra pilaris (PRP) following vaccination is rarely described in the literature. We report a case of PRP occurring two weeks after measles-mumps-rubella (MMR) vaccination. CASE REPORT: A 17-month-old infant was referred for a rash appearing two weeks previously. The child was presenting diffuse erythematous scaly exanthema with follicular papules and orange palmoplantar keratoderma. The clinical features were highly evocative of PRP. The histology was non-specific, displaying epidermal acanthosis with a regular and thick parakeratosis, and without any impairment of the follicular infundibulum. An MMR vaccination had been given two weeks before onset of the rash. Treatment with topical corticosteroids and emollients proved effective. DISCUSSION: Post-vaccinal PRP is rarely described in the literature. We report only the 3rd case. The first case concerned a 32-year-old woman presenting two episodes of PRP 10 days after diphtheria-tetanus-polio vaccination. The second case concerned a 47-year-old woman presenting PRP 18 days after anti-influenza vaccination and requiring treatment with acitretin. No cases have been described with MMR. These three vaccines (DTP, Tetragrip and ROR) have no shared pharmacological constituents, and the trigger mechanism could be immunological or parainfectious. CONCLUSION: Questioning about recent vaccination during history taking appears necessary to assess the importance of this trigger factor as well as the mechanism responsible for the onset of PRP.