Following the market authorization of interleukin (IL)-17 inhibitors, a growing number of cases of IL-17 inhibitor-induced paradoxical psoriasis (PsO) have been reported. Our objectives were to present two cases of IL-17 inhibitor-induced paradoxical PsO and to systematically review the literature for similar cases, summarizing and presenting the relevant data. A systematic literature review of previously presented cases of paradoxical PsO induced by IL-17 inhibitors was conducted. We presented two patients with axial spondyloarthritis (axSpA) and paradoxical PsO induced by secukinumab (SEC). One patient\'s psoriatic lesions responded well to adjuvant topical treatment, while the other patient required a combination of topical treatment and cyclosporine Α for successful treatment. SEC was continued in both cases. We also identified 35 patients with IL-17 inhibitor-induced paradoxical PsO in the literature review. The most frequent types of paradoxical PsO were palmoplantar pustular and plaque PsO, while the median latency period was 11 weeks. Approximately one-third of patients continued IL-17 inhibitor treatment with adjunctive therapy, primarily topical, which produced satisfactory results in most patients. Almost two-thirds of the patients discontinued the IL-17 inhibitor, with the majority of patients switching to another biological agent with a different mechanism of action or initiating other systemic antipsoriatic treatments, resulting in mainly satisfactory outcomes. Therefore, paradoxical PsO induced by IL-17 inhibitors appears to respond well in both patients who continue IL-17 inhibitors with adjunctive treatment and those who discontinue IL-17 inhibitors while switching to a different class of biological agent or initiating other systemic antipsoriatic treatments.

Hidradenitis suppurativa (HS) is a chronic autoinflammatory follicular disease, affecting body areas that are rich in apocrine glands. Moderate-to-severe HS may severely impair patients\' quality of life also because the available therapies are often unsatisfactory. Several lines of evidence suggest that inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin (IL)-17 play a pivotal role in the physiopathology of HS. TNF-α inhibitors have long been used with benefit in moderate-severe forms of HS. However, several monoclonal antibodies against IL-17 isoforms are currently being investigated for HS. We report the case of a 50-year-old man with long-standing HS and concomitant palmo-plantar psoriasis treated with brodalumab after failure of various TNF-α inhibitors. The HS lesions and the patient\'s quality of life improved steadily over time until week-136. Interestingly, the clinical benefit was confirmed by radiological improvement with MRI evaluation. Our case report demonstrates the long-term efficacy and safety of brodalumab in HS encouraging the use of drugs to inhibit the T helper-type 17 immune axis, especially in cases of HS refractory to therapy with TNF-α inhibitors.

Pustular psoriasis (PP) is a rare subtype of psoriasis. Overall, the growing evidence - in particular for acute generalized PP (GPP) - supports that it is a separate entity with a specific pathogenetic pathway. Interleukin (IL)-17/T-helper 17 (Th17) axis involvement may play an important role in the pathophysiology of PP. Biologicals, often required to achieve clinical remission, have changed the treatment of PP.
We provide the reader with an overview of all the available evidence on the use of the antibody-based therapy targeting IL-17A in patients with PP.
Although papers reported in this review do not provide definitive evidence (due to methodological limitations) to support the use of IL-17 inhibitors as potential first-line for the treatment of PP, based on our own experience and according to most of the reported literature, targeting IL-17A, may represent the best therapeutical approach in this peculiar clinical spectrum of psoriasis.

BACKGROUND: Interleukin-17 (IL-17) monoclonal antibody drugs have been increasingly significant in the treatment of psoriasis, but it is not clear whether the efficacy is equivalent across ethnicities.
OBJECTIVE: To explore the differences of short-term efficacy of IL-17 inhibitors between Caucasians and Asians.
METHODS: The pooled log risk ratio (logRR) between the groups was estimated. The meta-regression analysis on the logRR was performed, with the proportion of Caucasian patients as the covariate. The subgroup analysis was performed by specific IL-17 inhibitors.
RESULTS: Of the 1,569 potentially relevant studies, sixteen randomized controlled trials (RCTs) were included. For the Psoriasis Area and Severity Index 75 (PASI 75) response at week 12, the pooled logRR of the Asian group and the Caucasian group was 2.81 (95% CI: 2.27-3.35, p < 0.001) and 2.93 (95% CI: 2.71-3.16, p < 0.001), respectively, indicating no significant difference of efficacy between Asians and Caucasians. The meta-regression analysis did not show an association of the proportion of Caucasians with the effect size (β = 0.3203, p = 0.334). In the subgroup analysis, the comparison results of secukinumab were consistent with the main analysis.
CONCLUSIONS: Only the short-term efficacy was explored. The data from Asian countries were limited.
CONCLUSIONS: The short-term efficacy of IL-17 inhibitors in the treatment of psoriasis has no significant difference between Caucasians and Asians.
BACKGROUND: PROSPERO, identifier CRD42020201994, https://www.crd.york.ac.uk/prospero/.

An intact and fully functional immune system plays a crucial role in the prevention of several infectious diseases. Interleukin (IL)17 is significantly involved in oral mucosa immunity against several antigens and microorganisms, including Candida albicans (CA). Herein, we present three cases of oral candidiasis (OC) related to the use of an IL17A inhibitor for psoriasis. Three psoriatic individuals presented for evaluation of widespread symptomatic oral lesions temporally correlated with the onset of IL17A inhibitors (secukinumab in two patients and brodalumab in one patient). Clinical examination revealed either partially removable white plaques in an erythematous background (case #1) or diffuse erythematous lesions (cases #2 and 3) involving several areas of the oral mucosa. Cytology smear, accompanied by histopathologic examination in case #1, confirmed the clinical impression of OC in all three cases. All patients received antifungal therapy with satisfactory clinical response. No discontinuation of the antipsoriatic regimen was recommended, but all patients were advised to remain under monitoring for possible OC relapses. During the last few years, new systemic biologic agents targeting IL17 have been used for the management of variable immune-mediated diseases. Few clinical trials and scarce case reports have shown that these medications place individuals at high risk of developing candidiasis. We propose that patients treated with these medications should be at close monitoring for the development of OC and, if it occurs, receive appropriate management.

UNASSIGNED: Interleukin (IL)-17 inhibitors are a newer class of biologic used to treat patients with moderate-to-severe plaque psoriasis and psoriatic arthritis.
UNASSIGNED: We compared evidence-based clinical practice guidelines (CPGs) from leading dermatological organizations for the use of IL-17 inhibitors in psoriasis.
UNASSIGNED: Guidelines from the Joint American Academy of Dermatology-National Psoriasis Foundation (AAD-NFP) Guidelines, British Association of Dermatologists guidelines (BAD), and European S3 group (ES3) were all reviewed and compared.
UNASSIGNED: This analysis revealed significant overlap in the recommendations made by experts from each CPG. However, our review highlights differences in routine laboratory recommendations and the relative and absolute contraindications to use with IL-17 inhibitors.
UNASSIGNED: IL-17 inhibitors are an effective treatment option for psoriasis. This analysis and review of guidelines for IL-17 inhibitor use highlights the consensus in treatment protocols and areas of disagreement between CPGs.

The IL-17 pathway is a potential therapeutic target shown to be implicated in hidradenitis suppurativa (HS), however, it remains unclear whether evidence from mechanistic studies may translate into clinical practice. This systematic review summarizes available treatment outcomes of IL-17 inhibitors in patients with HS. Embase, MEDLINE, PubMed, and clinicaltrials.gov were comprehensively searched on February 26, 2021 to include 16 original studies representing 128 patients with HS (mean age: 36.5 years; age range: 21-47 years; male: 50.0%). Treatment outcomes were reported for the following biologics: secukinumab (n = 105), brodalumab (n = 22), and ixekizumab (n = 1). Patients were classified as responders or non-responders according to achievement of a positive response/improvement based on criteria established for each included study. For secukinumab 57.1% (n = 60/105) of patients were responders in a mean response period of 16.2 weeks and 42.9% (n = 45/105) were non-responders; for brodalumab, 100.0% (n = 22/22) of patients were responders within 4.4 weeks; and the one patient treated with ixekizumab was a responder within 10 weeks. In conclusion, IL-17 inhibitors may serve as an effective therapeutic target in approximately two-thirds of patients with HS and can be considered in those who are refractory to other treatment modalities. We also stress the importance of consistent outcome measures to enhance evidence synthesis, decrease reporting bias, provide potential for future meta-analysis, and ultimately improve clinical outcomes for patients with HS.

UNASSIGNED: Interleukin 17 is a proinflammatory cytokine considered to play a significant role in the immunopathogenesis of many chronic immune-mediated disorders. Interleukin 17 inhibitors provide an excellent treatment option for patients with psoriasis, psoriatic arthritis, or ankylosing spondylitis. However, Interleukin 17 inhibitors have been suspected of worsening or triggering new-onset inflammatory bowel disease.
UNASSIGNED: A literature search was conducted until March 2021 to investigate reporting prevalence, and characteristics of all gastroenterological adverse events in patients treated with Interleukin 17 inhibitors. One hundred and six clinical randomized trials were included, involving 40,053 patients. Inflammatory bowel disease cases were reported in 0.4% of patients exposed to Interleukin 17 inhibitors. The most frequent other gastrointestinal adverse events were diarrhea (2.5%), nausea or vomiting (0.7%), and gastroenteritis (0.2%). Sixty-one uncontrolled or retrospective studies were included, involving 16,791 patients. Sixty (0.36%) inflammatory bowel disease cases were reported, 0.6% of patients reported other gastrointestinal adverse events.
UNASSIGNED: Interleukin 17 inhibitors are safe and effective in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis. Low incidence rate of developing new-onset inflammatory bowel disease or exacerbating preexisting inflammatory bowel disease with anti-IL-17 agents has been reported. Clinicians should be aware of the possibility of these concerns when considering this therapy.

The treatment of moderate to severe plaque psoriasis in patients with history of malignancy is challenging. To review the studies reporting the experience with IL-17A inhibitors in patients with psoriasis and history of malignancy; secondly, to investigate cancer recurrence in a series of patients with a prior malignancy and plaque psoriasis treated with IL-17A inhibitors. A systematic literature review and an observational retrospective analysis of patients with history of malignancy and plaque psoriasis treated with IL-17A inhibitors was performed. About 5 original articles out of 601 were retrieved, reporting a total of 10 patients with a median age of 59 years, interquartile range (IQR) 50-63. Seven patients were treated with secukinumab, one with ixekizumab and two with both sequentially. Although the stage ranged from in situ to IV stage, most of the cases were early-stage neoplasm. The IL-17A inhibitor was initiated after a median of 10 months, interquartile range (IQR) 5-30 (range 0-144) from the diagnosis of malignancy. In addition, a series of 12 patients with history of malignancy were identified from the University Hospital of Verona, including 9 cases with cancer in clinical remission and 3 with advanced disease at time of initiating IL-17 inhibitor. No malignancy recurrence was reported within a median of 12 (IQR 6-23) and 46 (IQR 36-48) months follow up in case series from literature and our experience, respectively. Data on use of IL-17A inhibitors in patients with chronic plaque psoriasis and history of malignancy are limited. Registries and proactive pharmacovigilance activities are needed to guide clinical practice.

With our aging population, an increasing number of psoriasis patients are classified as elderly. However, psoriasis treatment in older adults can be challenging, given an increased number of comorbid conditions and immunosenescence. Biologic agents present a solution to this treatment dilemma because of their high efficacy and favorable tolerability. The objective of this systematic review was to summarize the findings of clinical trial and real-world studies exploring the safety and efficacy of biologic agents in elderly patients with moderate-to-severe psoriasis. We searched MEDLINE, Embase, the Cochrane Library, and clinical trial databases. Studies analyzing biologics for psoriasis were included if elderly patients were the main population of interest or were a separate subgroup in their analysis. Eighteen articles met inclusion criteria after screening. Across all biologic classes, efficacy for biologics between nonelderly adult patient and elderly patients was similar. Adverse events (AEs) and infections occured at a similar frequency between both groups. However, serious AEs were more common in the elderly. The available literature on the safety and efficacy of biologic agents in elderly patients supports the use of these agents in this population. However, serious AEs and discontinuation due to AEs were more common in older patients. As elderly patients have a higher burden of comorbid conditions and an increased baseline vulnerability for AE, physicians should continue to be prudent in screening before initiating biologics and monitor patients more closely as AEs tend to be more severe.