A case of juvenile pityriasis rubra pilaris: could varicella be an aetiological agent?

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 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.

Systemic therapies of pityriasis rubra pilaris: a systematic review

Pityriasis rubra pilaris (PRP) is a rare papulosquamous disorder. Treatment is challenging; the armamentarium consists of topical corticosteroids, phototherapy, classic systemic treatments such as retinoids or immunosuppressive drugs, and most recently biologicals. However, the relative effectiveness of therapies is unclear. Our objective was to review the published literature on systemic treatment of PRP. A systematic review was conducted on PubMed and the Cochrane Library up to 5 September 2017. Studies evaluating any systemic treatments of PRP (except for historical treatments) were included. Overall, 182 studies met the predefined inclusion criteria, and reported on 475 patients and 652 courses of treatment. 42.0 % (225/514) of all patients treated with retinoids achieved an excellent response (isotretinoin: 61.1 % [102/167], etretinate: 47 % [54/115], and acitretin: 24.7 % [43/174]) compared to an excellent response rate of 33.1 % (53/160) with methotrexate. Therapy with biologicals was successful in 51.0 % of patients (71/133) (ustekinumab: 62.5 % [10/16], infliximab: 57.1 % [28/49], etanercept: 53.3 % [16/30], and adalimumab: 46.4 % [13/28]). This review balances effectiveness, side effects, experience, and drug costs in order to suggest a treatment regimen starting with isotretinoin as first-line, methotrexate as second-line and biologicals as third-line treatment for this difficult-to-treat dermatosis.

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.

An unusual cluster of circumscribed juvenile pityriasis rubra pilaris cases

Circumscribed juvenile pityriasis rubra pilaris (PRP) is an uncommon dermatosis. We describe the unusual clustering of circumscribed juvenile PRP cases in our pediatric dermatology clinic in 2011. A retrospective chart review was done of patients presenting during the summer of 2011 with classic findings of circumscribed juvenile PRP. Clinical data including past medical and family history, presenting symptoms, infectious disease history and evaluation, biopsy results, and management were recorded. Seven patients, ages 5 to 19 years, all had strikingly similar skin findings of pink to hyperpigmented, well-defined, scaly papules and plaques on their elbows, knees, dorsal hands, ankles, and Achilles tendons. Four of the seven also had palmoplantar involvement. Four were sibling pairs and the other three were unrelated. Streptococcus pyogenes infection was suspected as a trigger in four of the patients. The unusual clustering of this uncommon disease, along with the occurrence in two sibling pairs, suggests that a genetic susceptibility unmasked by an infectious agent may play a role in its pathogenesis.

Pityriasis rubra pilaris: a review of diagnosis and treatment

Pityriasis rubra pilaris (PRP) is a rare inflammatory dermatosis of unknown etiology, and finding a successful therapy can be challenging. PRP occurs equally in men and women. In some patients, associated autoimmune diseases, infections, or malignancies are possible trigger factors. PRP shows a bimodal age distribution, peaking in the first as well as in the fifth to sixth decade. Its classification into five subgroups is based on age at onset, clinical course, morphologic features, and prognosis. More than 50% of patients are best classified as type I with adult-onset PRP. This form is also characterized by high spontaneous remission rates (80%) within 1-3 years. Clinically, the classical adult (type I) and classical juvenile (type III) forms appear to be the same except for the patient's age. Recently, the designation of a new category of PRP (type VI) has been proposed that is characterized by the presence of HIV infection with different clinical features and a poorer prognosis. Typical morphologic features of PRP are erythematosquamous salmon-colored plaques with well demarcated islands of unaffected skin. Often, keratoderma of the palms and soles is present. In patients with extensive disease, ectropion is a dreaded complication. Histology shows hyperkeratosis, alternating orthokeratosis and parakeratosis in a checkerboard pattern, and focal acantholytic dyskeratosis. Descriptions and therapeutic experiences are mainly based on case reports. Mostly, systemic retinoids, methotrexate, and other immunosuppressive agents as well as UV light therapy are applied, with varying response rates. In recent years, treatment with so-called 'biologics' is becoming more and more popular for treating recalcitrant PRP. We present a review of the clinical features, histopathologic findings, classification, differential diagnoses, and treatment of PRP.