Alitretinoin (9-cis Retinoic Acid) is Effective Against Pityriasis Rubra Pilaris: A Retrospective Clinical Study

Abstract

Pityriasis rubra pilaris (PRP) is an uncommon cutaneous disease with disorder of keratinisation. Up to now, systemic retinoids like acitretin or isotretinoin seem to be the most effective therapeutic agents. However, no large trials on this rare disease have been published and no standardised treatment has been established so far. Recently, single case reports demonstrate beneficial effects of alitretinoin (9-cis retinoic acid) in patients with PRP. We performed a retrospective observational analysis of type I adult-onset patients with PRP (n = 5) treated with systemic alitretinoin in our department. Alitretinoin was highly effective in the treatment of PRP in 4 of 5 cases. PASI score was reduced significantly in the alitretinoin responders. We assume that alitretinoin could serve as an additional effective systemic treatment option for type I adult-onset PRP.

Type II Pityriasis Rubra Pilaris Associated with Grave's Disease-Case Report

“…Without the thyroid hormone, this conversion is almost abolished [12]. But deficiency of the thyroid hormone might outweigh the autoimmunity, since the reported cases of PRP and hypothyroidism did improve only with thyroxine replacement [11][12][13][14]. Based on our experience with this case, we favour an autoimmune hypothesis, since in thyrotoxicosis; there should be no impediment in the conversion of dietary carotenoids to active vitamin-A.…”

“…This finding could indicate either a defect in vitamin A absorption or a carrier protein deficiency. These defects could be an explanation to why topical vitamin A is more effective than parenteral supplements [9,11].…”

“…PRP has been linked to many autoimmune diseases-myasthenia gravis, coeliac disease, and hypothyroidism [11][12][13][14]. Hypothyroidism can theoretically be linked to autoimmunity predispositions, as well as thyroid hormone deficiency, which is needed to convert the dietary carotenoids to an active vitamin A.…”

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“…Topical emollients are used for dryness and cracking and retinoids are reported to be effective in severe conditions. It is recommended that isotretinoin 1-1.5 mg/kg/day or etretinate 1mg/kg/ day are to be taken for optimum therapeutic effect [31][32] .…”

Two Cases of Successful Treatment of Refractory Chronic Inflammatory Skin Disease, Atopic Dermatitis and Psoriasis with Oral Alitretinoin

“…Anti-inflammatory and immunomodulatory effects and anti-proliferative and apoptotic effects could explain the mechanism of action also in AD. In vitro, alitretinoin inhibited production of nitric oxide and proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-12p4024. The efficacy of TNF-α inhibitors and the blocking IL-12/IL-23 antip40 monoclonal antibody ustekinumab against psoriasis was shown many times2.…”