Successful Treatment of Pityriasis Rubra Pilaris with Ixekizumab

Abstract

Pityriasis rubra pilaris is an inflammatory dermatologic disorder of unknown cause and often confounded with psoriasis. It is characterised by hyperkeratotic follicular papules, scaly erythematous plaques, palmoplantar keratoderma, and a progression to generalised erythroderma. Here, we report the case of a 68-year-old man with pityriasis rubra pilaris, who was successfully treated with ixekizumab, an interleukin-17A inhibitor.

Histopathologic findings characteristic of CARD14‐associated papulosquamous eruption

“…The presence of CARD14 mutations and histopathologic similarities between CAPE, psoriasis, and PRP point to a shared pathogenesis featuring activation of the Th17 pathway, and agents targeting this pathway have efficacy in all three diseases . Recent studies show that other Th17‐activating genodermatoses include various ichthyoses, and trials using similar agents are underway …”

“…These are canonical pathways implicated in psoriasis. Interestingly, inhibition of the Th17 pathway has now shown therapeutic benefit in psoriasis, PRP, and CAPE . In this study, we discuss histopathologic findings in patients diagnosed as having CAPE.…”

Case of pityriasis rubra pilaris progressed to generalized erythroderma following blockade of interleukin‐17A, but improved after blockade of interleukin‐12/23 p40

“…Not all patients responded to anti-IL-17A, suggesting that further studies are required to evaluate the role of IL-17 in PRP patients. In a recent report on a PRP patient successfully treated with another anti-IL-17A antibody, ixekizumab, Hanfstingl et al 5 referred to the previous paper that clinical improvement was paralleled by a decrease in lesional Th17 cytokines during effective anti-IL-12/IL-23 therapy with ustekinumab, 7,8 and highlighted the IL-23/IL-17 axis in the pathogenesis of PRP. Successful treatments for refractory PRP with ustekinumab have been recently reported.…”

“…Our present case progressed to generalized erythroderma after treatment with IL‐17A antibody secukinumab. But there are some reports of successful treatment of PRP with anti‐IL‐17A . Bonomo et al .…”

“…But there are some reports of successful treatment of PRP with anti-IL-17A. [2][3][4][5] Bonomo et al 2 and Schuster et al 3 reported two cases and a case of PRP, respectively, successfully treated with anti-IL-17A, who were estimated to be type I PRP in their clinical course. Gauci et al 4 described a case of type II PRP well-treated with secukinumab.…”