Pityriasis rubra pilaris



Pityriasis rubra pilaris


Anne-Marie Tobin and Brian Kirby


Evidence Levels:  A Double-blind study  B Clinical trial ≥ 20 subjects  C Clinical trial < 20 subjects  D Series ≥ 5 subjects  E Anecdotal case reports


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Pityriaisis rubra pilaris is a rare papulosquamous disorder characterized by erythroderma, orange-red keratoderma, and ‘islands of sparing’. It can divided into six subtypes based on morphological phenotype, age of onset, and presence of HIV infection:



More than 50% of cases are of the classical type I adult onset pityriasis rubra pilaris. The majority of cases of type I classical pityriasis rubra pilaris go into spontaneous remission after 1 to 3 years.


As pityriasis rubra pilaris is a rare condition, there are no randomized controlled trials assessing treatment efficacy. Treatment recommendations are based on case reports and small case series. Pityriasis rubra pilaris has been reported in association with malignancy. These reports have been inconsistent and suggest a chance occurrence rather than a true association.



Management strategy


Topical therapies are primarily used as anti-pruritic agents. Emollient use should be encouraged in combination with emollient baths. Topical steroids may reduce pruritus but are often ineffective.


There are a few case reports of effective use of both narrowband UVB and PUVA for pityriasis rubra pilaris. Pityriasis rubra pilaris can often be exacerbated by UV light and we recommend that narrowband UVB and PUVA are only used cautiously and only when other treatments are contraindicated.


Oral retinoids have been the mainstay of therapy for classical type I and type III pityriasis rubra pilaris. Doses of 0.5 mg/kg of acitretin and upwards are required for adequate control. This often results in significant mucocutaneous side effects and hair loss. Skin fragility and pruritus are common side effects at these doses. It is our practice to initiate treatment with acitretin for rapid improvement but to add in a second oral agent (usually methotrexate) if intolerable side effects ensue.


Methotrexate has been reported in several case series as being effective in classical type I pityriasis rubra pilaris. The long-term efficacy of methotrexate is well established. Doses of up to 30 mg weekly are necessary and concomitant folic acid is recommended. Despite reservations of its use with acitretin regarding hepatotoxicity it has been reported as a safe combination and we would concur with that view.


Due to its similarity to psoriasis, pityriasis rubra pilaris has been treated with TNF-α inhibitors. The use of TNF inhibitors appears effective in the treatment of pityriasis rubra pilaris and has been the subject of an excellent systematic review.


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Aug 7, 2016 | Posted by in Dermatology | Comments Off on Pityriasis rubra pilaris

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