Pityriasis rubra pilaris (PRP) is a rare, papulosquamous, inflammatory skin disease. PRP represents a therapeutic challenge. The rarity of this disease and its possible spontaneous remission makes the conduction and interpretation of therapeutic studies particularly difficult. Moreover, PRP not infrequently proves resistant to common topical and conventional systemic therapies. In this context, numerous biologic agents have been reported in PRP treatment. The aim of our manuscript was to review the current literature to evaluate the possible role of biologics targeting the IL17/23 axis in PRP management. Recent cases in the literature have highlighted the use of several promising drugs: IL-17 inhibitors, IL-23 inhibitors, and the IL-12/23p40 inhibitor ustekinumab. However, it should be noted that all these drugs are approved for moderate-to-severe plaque psoriasis and their use in PRP is off label. The treatment of PRP is based on clinical experience, case reports or case series reported in the literature, as randomized controlled trials are difficult to conduct due to the rarity of the condition. Despite data on the efficacy of drugs targeting IL-17 and IL-23 being promising, they are still limited. Certainly, further studies are desirable to better characterize PRP and establish shared guidelines.

Hidradenitis suppurativa (HS) is a chronic, relapsing inflammatory skin disease associated with significant physical and psychosocial burden. Increasing evidence identifies the interleukin (IL)-17 pathway as a central driver of HS pathogenesis. Elevated levels of IL-17 family cytokines, particularly IL-17A and IL-17F, have been consistently demonstrated in lesional skin, where they contribute to keratinocyte activation, neutrophil recruitment, and amplification of proinflammatory cascades. This review provides a comprehensive overview of the pathogenic role of IL-17 in HS and summarizes current evidence on IL-17-targeted therapies from clinical trials and real-world studies. Secukinumab, a selective IL-17A inhibitor, has shown significant efficacy in phase III trials, with clinically meaningful improvements in Hidradenitis Suppurativa Clinical Response (HiSCR), pain, and quality of life, sustained over long-term follow-up. Bimekizumab, a dual inhibitor of IL-17A and IL-17F, has demonstrated robust and consistent efficacy across multiple endpoints, including higher response rates and greater improvements in patient-reported outcomes, supporting the relevance of dual cytokine inhibition. Despite these advances, treatment responses remain heterogeneous, reflecting the multifactorial nature of HS. Further research is needed to identify predictive biomarkers and optimize therapeutic strategies.