Ixekizumab: An efficacious treatment for both psoriasis and hidradenitis suppurativa

Biologics for Hidradenitis suppurativa: evolution of the treatment paradigm

INTRODUCTION

Hidradenitis suppurativa (HS) is an autoinflammatory skin disease with a high unmet need for effective medical management. Clinically, it is characterized by inflammatory nodules that may progress into abscesses, draining tunnels and extensive scarring, mainly affecting apocrine gland-bearing areas.

AREAS COVERED

Treatment options include topical and systemic medications and a variety of surgical procedures. The anti-TNF-α antibody adalimumab and the anti-IL-17 secukinumab are the only two approved biologics for HS, showing moderate efficacy. HS research is a rapidly growing field, with a wide range of agents leveraging distinct mechanisms of action currently under development. Drugs targeting the IL-17 and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways are the most advanced in both ongoing and completed Phase 3 studies, promising deeper levels of response. Use of other, off-label biologics is also discussed.

EXPERT OPINION

A therapeutic algorithm is proposed based on comorbidities and existing evidence. Patient-tailored combinations between biologics and other biologics or small molecules will hopefully allow clinicians to target most events in HS pathophysiology in a complementary way while obtaining a meaningful effect on their devastating manifestations.

Narrative Review and Update on Biologic and Small Molecule Drugs for Hidradenitis Suppurativa: An Entity With a Promising Future

Hidradenitis suppurativa (HS) is a chronic inflammatory entity characterized by the appearance of multiple nodules, abscesses, and fistulas, predominantly in apocrine regions. In addition to its dermatological involvement, it is associated with multiple systemic comorbidities. Its treatment is combined: topical pharmacological, systemic pharmacological and surgical. Regarding biologic or small molecule drugs, currently only adalimumab is approved. A narrative review of the literature on biological or small molecule drugs used in the treatment of hidradenitis suppurativa is presented. The arsenal we found is large, with multiple targets: inhibitors of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-17, IL-23, IL-1, inhibitors of the janus kinase (JAK) pathway, and multiple other drugs in study. New prospective studies and comparative trials are needed to analyze the effectiveness and safety of these treatments, in an entity with a promising future.

Narrative Review and Update on Biologic and Small Molecule Drugs for Hidradenitis Suppurativa: An Entity With a Promising Future

Hidradenitis suppurativa (HS) is a chronic inflammatory entity characterized by the appearance of multiple nodules, abscesses, and fistulas, predominantly in apocrine regions. In addition to its dermatological involvement, it is associated with multiple systemic comorbidities. Its treatment is combined: topical pharmacological, systemic pharmacological and surgical. Regarding biologic or small molecule drugs, currently only adalimumab is approved. A narrative review of the literature on biological or small molecule drugs used in the treatment of hidradenitis suppurativa is presented. The arsenal we found is large, with multiple targets: inhibitors of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-17, IL-23, IL-1, inhibitors of the janus kinase (JAK) pathway, and multiple other drugs in study. New prospective studies and comparative trials are needed to analyze the effectiveness and safety of these treatments, in an entity with a promising future.

Emerging Treatments and the Clinical Trial Landscape for Hidradenitis Suppurativa Part I: Topical and Systemic Medical Therapies

Hidradenitis suppurativa (HS) is an oftentimes debilitating condition that presents with painful nodules, abscesses, and sinus tracts. This condition is challenging to treat, in part because the pathogenesis of the condition is incompletely understood but also because there are limited therapeutic options. HS research is undergoing explosive growth with multiple new molecular pathways under study, which will hopefully lead to improved disease control for patients. Part I of this review will provide an overview of the emerging topical and systemic therapies under investigation for HS.

New Insight into the Molecular Pathomechanism and Immunomodulatory Treatments of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is an immune-mediated inflammatory disorder characterized by deep-seated nodules, abscesses, sinus tracts and scars localized in the intertriginous areas. It is accompanied by pain, malodourous secretion and a dramatically decreased quality of life. Although the pathogenesis has not been entirely elucidated, the primary event is follicular hyperkeratosis of the pilosebaceous apocrine unit. Since the registration of the tumor necrosis factor-alpha inhibitor Adalimumab in 2015, several cytokines have been implicated in the pathomechanism of HS and the research of novel therapeutic targets has been intensified. We provide an update on the inflammatory cytokines with a central role in HS pathogenesis and the most promising target molecules of future HS management.

Adalimumab, Ustekinumab, and Secukinumab in the Management of Hidradenitis Suppurativa: A Review of the Real-Life Experience

To date, adalimumab (ADA) is the only biotechnology drug approved for the management of hidradenitis suppurativa (HS), an inflammatory skin condition. However, it quickly became apparent that the efficacy of adalimumab in daily practice was highly variable. In our review, we highlighted the current evidence from literature on the use of biologics in HS in a real-life setting, particularly adalimumab, secukinumab and ustekinumab. Data on the effectiveness and safety of biologic drugs in HS management have been analyzed. Even if the results are promising, more studies are needed. In our opinion, the armamentarium of drugs for HS management is increasing, and treatment will be based on a tailored-tail approach, minimizing the risk of adverse events. In this context, we want to point out the reported effectiveness and safety data concerning adalimumab, ustekinumab and secukinumab as well as ixekizumab.

Novel and Off-Label Biologic Use in the Management of Hidradenitis Suppurativa, Pyoderma Gangrenosum, Lichen Planus, and Seborrheic Dermatitis: A Narrative Review

With advances in drug development and our understanding of the pathophysiology of skin disease, biologic medications have emerged as powerful management tools for dermatologists. While biologics have most often been used in the management of psoriasis, they are being used off-label for the management of a variety of other immune-mediated skin diseases with overlapping molecular targets. This narrative review focuses on the novel and off-label use of biologic medications for the management of hidradenitis suppurativa (HS), pyoderma gangrenosum (PG), lichen planus (LP), and seborrheic dermatitis (SD). Review of the literature revealed that IL-17, IL-23, and tumor necrosis factor (TNF) inhibitors were being used across a variety of immune-mediated skin pathologies with variable efficacy, among other targeted biologics. While biologics were generally safe in the treatment of primary immune-mediated skin disorders, paradoxical disease eruptions were noted with biologic use and were theorized to occur owing to immune dysregulation and cytokine imbalance. While numerous case reports show promise for the use of biologics in immune-mediated skin pathologies, the variable efficacy and safety reported warrants more thorough investigations of the role of these targeted medications in comprehensive disease management.

IL-17A is a pertinent therapeutic target for moderate-to-severe hidradenitis suppurativa: Combined results from a pre-clinical and phase II proof-of-concept study

Hidradenitis Suppurativa (HS) is a chronic, recurrent, inflammatory, follicular skin disease whose pathology is complex and not fully understood. The objective of this study was to elucidate the role of IL-17A in moderate-to-severe HS. Transcriptomic and histological analyses were conducted on ex vivo HS (n = 19; lesional and non-lesional) and healthy control (n = 8) skin biopsies. Further, a Phase II exploratory, randomized, double-blind, placebo-controlled study was carried out in moderate-to-severe HS patients. Patients were treated with either CJM112 300 mg (n = 33), a fully human anti-IL-17A IgG1/κ monoclonal antibody, or placebo (n = 33). The main outcome of the translational analyses was to identify IL-17A-producing cells and indications of IL-17A activity in HS lesional skin. The primary objective of the clinical study was to determine the efficacy of CJM112 in moderate-to-severe HS patients by HS-Physician Global Assessment (HS-PGA) responder rate at Week 16. Transcriptomic and histopathologic analyses revealed the presence of heterogeneous cell types in HS lesional skin; IL-17A gene signatures were increased in HS lesional vs non-lesional or healthy skin. High expression of IL-17A was localized to T cells, neutrophils, and mast cells, confirming the transcriptional data. Clinically, the proportion of Week 16 HS-PGA responders was significantly higher (p = 0.03) in the CJM112 group vs placebo (32.3% vs 12.5%). This study elucidated the role of the IL-17A pathway in HS pathogenesis and clinically validated the IL-17A pathway in moderate-to-severe HS patients in a proof-of-concept study using the anti-IL-17A-specific antibody CJM112.

Immunomodulatory Drugs in the Treatment of Hidradenitis Suppurativa—Possibilities and Limitations

Hidradenitis suppurativa, also known as acne inversa, is a chronic, progressive, debilitating, recurrent inflammatory skin disease characterized by the occurrence of very severe, persistent, painful nodules, abscesses, and fistulas, most commonly found in the skin folds of the axilla, groin, gluteal, and perianal areas. Treatment is rather difficult and typically requires the use of multiple modalities. Regardless of the presence of several therapeutic options, treatment often turns out to be ineffective or poorly selected concerning the clinical picture of the disease. Thus, the search for new biologics and other target treatments of hidradenitis suppurativa is ongoing. The safety and efficacy of adalimumab, still the only U.S. Food and Drug Administration approved biologic in the hidradenitis suppurativa treatment, paved the way for new drugs to be compared with it. Several more drugs with new immunological targets are currently under investigation for the treatment of acne inversa. The aim of the article was to present the current and future targets of acne inversa treatment, simultaneously providing insights into the molecular pathomechanisms of the disease.

Guselkumab, Risankizumab, and Tildrakizumab in the Management of Psoriasis: A Review of the Real-World Evidence

Interleukin (IL)-23 inhibitors, guselkumab, risankizumab, and tildrakizumab, represent the latest class of biologics approved for the treatment of moderate-to-severe psoriasis. Since their approval numerous real-life studies were published on anti-IL-23 use in routine clinical practice. Indeed, real-life data are important to improve the dermatological decision-making process, including patients who are typically excluded from clinical trials, such as subjects suffering from several comorbidities, subjects on polypharmacy, as well as multifailure patients. Herein, we performed a comprehensive literature review about real-life data available on guselkumab, risankizumab, and tildrakizumab. Real-life data of anti-IL-23 seem to confirm the promising results of IL-23 shown by clinical trials, highlighting the efficacy and safety profiles of this new class of biologics also in clinical practice.

An Anti-Interleukin-17A Monoclonal Antibody, Ixekizumab, in the Treatment of Resistant Hidradenitis Suppurativa: A Case Series

INTRODUCTION

Although adalimumab is the only approved biologic for the treatment of hidradenitis suppurativa (HS), the treatment response may not be satisfactory in all patients. Recently, many other biological agents, including interleukin 17 inhibitors such as ixekizumab, have shown promise.

CASE PRESENTATIONS

Five severe HS (Hurley stage III) patients resistant to conventional treatments and adalimumab for at least 3 months were recruited. Patients were prescribed ixekizumab with a scheme approved for psoriasis (160 mg once, followed by 80 mg at weeks 2, 4, 6, 8, 10, and 12.) The primary outcome measure was achieving the Hidradenitis Suppurativa Clinical Response (HiSCR) score following 12 weeks. Secondary outcome measures included the patient-reported Dermatology Life Quality Index (DLQI) and visual analog scale (VAS). Four of 5 patients (80%) achieved HiSCR. While improvement was observed in the VAS and DLQI scores of 4 patients, the decline was limited in 1 patient. No adverse event was recorded related to ixekizumab.

CONCLUSION

The result of our observation suggests that ixekizumab may be effective for HS, especially in challenging cases.

Ixekizumab and brodalumab indirect comparison in the treatment of moderate to severe psoriasis: results from an Italian single-centre retrospective study in a real-life setting

BACKGROUND

Eleven biologic drugs are currently approved for psoriasis management. Real-life studies are needed to guide clinicians in choosing a tailored-tail therapy. The aim of our retrospective study is to indirectly compare the efficacy and safety of ixekizumab and brodalumab in psoriasis patients.

METHODS

A single-centre real-life retrospective study was performed enrolling moderate-to-severe psoriatic patients under biologic treatment with ixekizumab or brodalumab. For each patient, clinical and demographic data were collected and the effectiveness and safety of brodalumab and ixekizumab treatment were evaluated at weeks 4, 12 and 24. Psoriasis Area Severity Index (PASI) and Body Surface Area (BSA) were used for psoriasis severity.

RESULTS

A total of 139 patients were included in the study: 98(70.5%) and 41(29.5%) patients received ixekizumab and brodalumab, respectively. Mean PASI and BSA significantly reduced at each follow up for both ixekizumab and brodalumab groups. Even if ixekizumab reached higher rates of PASI90 and PASI100 than brodalumab (PASI90: 43.8%vs39.0% PASI100: 20.4%vs17.1% at week4 and PASI90: 83.6%vs75.6% PASI100: 71.5%vs60.9% at week24), these results were not statistically significant. Adverse events, mainly mild, were registered in 25.5% of ixekizumab and 26.8% of brodalumab group, respectively. Discontinuation rate was higher for brodalumab (17.1%vs9.1%), without statistical significance.

CONCLUSION

Our study showed comparable efficacy and safety for ixekizumab and brodalumab.

Advances in biologic and small molecule therapies for hidradenitis suppurativa

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, debilitating inflammatory skin disorder characterized by painful nodules, abscesses, fistulae, and scarring with a predilection for flexural regions. Several biologics and small molecule inhibitors are being evaluated in clinical trials for treatment.

AREAS COVERED

The authors discuss the data available from clinical trials and smaller, high-quality studies for existing and emerging biologic and small molecule inhibitor therapies for treatment of HS. Biologics discussed include TNFα, IL-17, IL-23, IL-12/23, and IL-1 inhibitors. Small molecule inhibitors discussed include PDE4, JAK, TYK, IFX-1, and complement cascade inhibitors. Pharmacokinetics and pharmacodynamics for these drugs are also described.

EXPERT OPINION

Trial data and our own experience have shown that about half of HS patients experience improvement with adalimumab. However, there is a significant need for pharmacotherapies with higher efficacy goals as in those used for psoriasis. Many biologics and small molecule inhibitors are being tested in clinical trials. The landscape of upcoming therapies for hidradenitis suppurativa appears promising.

New and Emerging Targeted Therapies for Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease deriving from the hair follicles. The formation of inflammatory nodules, abscesses, fistulas, and sinus tracts is characterized by a large inflow of key pro-inflammatory mediators, such as IFN-γ, TNF-α, IL-1, IL-17, and IL-12/23. Adalimumab is currently the only Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved biologic therapy for moderate to severe HS in adults and adolescents. However, the long-term effectiveness of this TNF-α inhibitor in HS patients has shown to be highly variable. This review aims to review the evidence for emerging therapies that target the main pro-inflammatory cytokines in HS pathogenesis. A review of the literature was conducted, using the PubMed and Google Scholar repositories, as well as Clinicaltrials.gov. Presently, the most promising biologics in phase III trials are anti-IL-17 antibodies, secukinumab, and bimekizumab. Furthermore, an anti-IL-1 biologic, bermekimab, is currently in phase II trials, and shows encouraging results. Overall, the clinical efficacies of all new targeted therapies published up to this point are limited. More studies need to be performed to clarify the precise molecular pathology, and assess the efficacy of biological therapies for HS.

Paradoxical Hidradenitis Suppurativa during Biologic Therapy, an Emerging Challenge: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease usually occurring after puberty with painful, deep-seated, inflammatory lesions in the apocrine gland-bearing areas of the body. Although HS pathogenesis is still unproven, recent major research advantages have increased our knowledge of the mechanisms behind HS lesions. Particularly, follicular occlusion followed by follicular rupture has been shown to be crucial to HS development, leading to immune response activation, and resulting in typical clinical HS lesions. Moreover, an increased and imbalanced cytokine production, such as interleukin (IL) 17 and tumor necrosis factor (TNF) α, may play a role in HS. In recent years, paradoxical adverse events have been described during treatment. Since the recent increased use of biologic treatments in HS, an increased number of paradoxical HS occurrences have been reported. In this review, we analyzed all current data on paradoxical HS triggered by biological drugs.

New perspectives on the treatment of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by the presence of painful nodules, abscesses, chronically draining fistulas, and scarring in apocrine gland-bearing areas of the body. The exact pathogenesis of HS is not yet well understood, but there is a consensus in considering HS a multifactorial disease with a genetic predisposition, an inflammatory dysregulation, and an influence of environmental modifying factors. Therapeutic approach of HS is challenging due to the wide clinical manifestations of the disease and the complex pathogenesis. This review describes evidence for effectiveness of current and emerging HS therapies. Topical therapy, systemic treatments, biological agents, surgery, and light therapy have been used for HS with variable results. Adalimumab is the only US Food and Drug Administration (FDA) approved biologic agent for moderate-to-severe HS, but new therapeutic options are being studied, targeting different specific cytokines involved in HS pathogenesis. Comparing treatment outcomes between therapies is difficult due to the lack of randomized controlled trials. Treatment strategy should be selected in concordance to disease severity and requires combination of treatments in most cases.

Insights into the Pathogenesis of HS and Therapeutical Approaches

Hidradenitis suppurativa (HS) is a debilitating, chronic, (auto)inflammatory disease primarily affecting apocrine gland-rich areas of the body. Although pathogenic mechanisms responsible for HS have not yet been fully elucidated, it is a multifactorial process whose main target is the terminal follicle. The role of the inflammatory process (and consequently of cytokine milieu) and of several other factors (genetics, lifestyle, hormonal status, microbiome, innate and adaptive immune systems) involved in HS pathogenesis has been investigated (and often defined) over the years with a view to transferring research results from bench to bedside and describing a unique and universally accepted pathogenetic model. This review will update readers on recent advances in our understanding of HS pathogenesis and novel (potential) medical therapies for patients with moderate-to-severe HS.

Onset of vitiligo in a psoriasis patient on ixekizumab

INTRODUCTION

Vitiligo is an acquired skin disorder clinically characterized by hypopigmentated macules and patches. Psoriasis is a chronic-inflammatory-skin-condition characterized by erythematous-plaques covered with scales particularly over the extensor-surfaces, scalp, and lumbosacral region. Recent major-researches-advancements have significantly expanded our understanding of psoriasis-pathophysiology, resulting in the development of highly effective targeted-therapies, such as anti TNFα, IL-12/23-inhibitors, IL-17-inhibitors, or IL-23-inhibitors. Particularly, ixekizumab, a humanized-monoclonal immunoglobulin-G 4 antibody, specifically binding IL-17A, demonstrated strong efficacy in threating recalcitrant psoriasis. Nevertheless, paradoxical reactions due to IL-17 inhibitors have been described.

CASE REPORT

Herein, we report the case of a 53-year-old Caucasian man who obtained complete skin clearance of psoriasis plaques after 16 weeks of ixekizumab treatment together with the appearance of vitiligo patches localized on the facial area. He had never suffered of vitiligo and his family history excluded vitiligo diagnosis. We also could exclude post inflammatory psoriasis hypopigmentation because of absence of facial involvement at baseline. Our experience suggests that vitiligo might be considered a rare adverse effects of anti-IL-17 therapy.

Hidradenitis Suppurativa: Where We Are and Where We Are Going

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease primarily affecting apocrine gland-rich areas of the body. It is a multifactorial disease in which genetic and environmental factors play a key role. The primary defect in HS pathophysiology involves follicular occlusion of the folliculopilosebaceous unit, followed by follicular rupture and immune responses. Innate pro-inflammatory cytokines (e.g., IL-1β, and TNF-α); mediators of activated T helper (Th)1 and Th17 cells (e.g., IFN-γ, and IL-17); and effector mechanisms of neutrophilic granulocytes, macrophages, and plasma cells are involved. On the other hand, HS lesions contain anti-inflammatory mediators (e.g., IL-10) and show limited activity of Th22 cells. The inflammatory vicious circle finally results in pain, purulence, tissue destruction, and scarring. HS pathogenesis is still enigmatic, and a valid animal model for HS is currently not available. All these aspects represent a challenge for the development of therapeutic approaches, which are urgently needed for this debilitating disease. Available treatments are limited, mostly off-label, and surgical interventions are often required to achieve remission. In this paper, we provide an overview of the current knowledge surrounding HS, including the diagnosis, pathogenesis, treatments, and existing translational studies.

Treatment Outcomes of IL-17 Inhibitors in Hidradenitis Suppurativa: A Systematic Review

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.

[Systemic treatment of moderate/severe hidradenitis suppurativa]

Systemic treatment together with radical surgical excision is the most important treatment option for all severity grades of hidradenitis suppurativa. Tetracycline in mild-to-moderate forms and clindamycin in combination with rifampicin in moderate-to-severe forms are guideline-compliant first-line therapy with a good clinical response. Other antibiotics such as ertepenem or multiple combinations are recommended as last-line therapy due to a lack of data. Success rate with dapsone and retinoids, on the other hand, are insufficient-only acitretin can be recommended on the basis of the available studies, but with limited success. With the TNF-alpha blocker adalimumab, an effective and safe long-term therapy is available-further biologics are in clinical trials and could significantly expand the treatment portfolio in the future.

Long-standing refractory hidradenitis suppurativa responded to a brodalumab monotherapy in a patient with psoriasis: A possible involvement of Th17 across the spectrum of both diseases

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic inflammatory skin disease mainly affecting apocrine gland-rich areas of the body with painful nodules, persisted abscess, sinus tracts, and scarring. The etiopathology of HS remains unclearly understood, but the disease is considered as a polygenic autoinflammation condition originating from follicular hyperkeratosis and occlusion. Recent advances concerning the substantial roles of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-17, and IL-23 have accelerated in developing a repertoire of therapeutic biologics in HS. Currently five biologics antagonistic for these different cytokines, adalimumab, anakinra, etanercept, infliximab, and ustekinumab, have been explored in the treatment setting of HS; however, only limited evidence is available for the therapeutic advantage of IL-17 pathway blockade. We present a 47-year-old Japanese man who had a long-standing, debilitating HS complicated with psoriasis, both of which were refractory to a series of the standard treatment. Not only psoriatic skin but also HS lesions responded dramatically to brodalumab, an IL-17 receptor antagonist, accompanied with decrease of validated assessments, namely the Hurley's staging classification and modified Sartorius score. Brodalumab was well tolerated with rapid improvement and no adverse reaction, and finally gave a satisfactory maintenance of disease remission. To our best knowledge, this is the first successful use of anti-IL-17 receptor antibody in a Japanese case with coexistence of HS and psoriasis. We also discuss extending understanding of the potential benefit and current limitation of brodalumab in the treatment of HS.

Skin manifestations in spondyloarthritis

Spondyloarthritides (SpA) like psoriatic arthritis, axial spondyloarthritis/ankylosing spondylitis, reactive arthritis and inflammatory bowel disease (IBD)-associated SpA can present with characteristic skin manifestations. These SpA-associated skin disorders may precede joint involvement, reflect a loss of efficacy of a current systemic treatment or can even be treatment associated. Cutaneous manifestations in SpA not only add additional morbidity with physical impact but also impose a psychosocial burden on affected patients. Psoriasis (PsO) - the main skin disease in SpA - has a variety of clinical presentations, including plaque-type PsO, inverse PsO, guttate PsO, erythrodermic PsO, nail PsO and pustular types. SpA associated with IBD presents with neutrophilic and granulomatous skin disorders, including pyoderma gangrenosum, hidradenitis suppurativa and cutaneous Crohn's disease. Reactive arthritides has a favourable prognosis and may feature keratoderma blenorrhagicum or balanitis circinatum as typical skin manifestations. Immunologically, SpA-associated skin diseases share interleukin (IL)-17 and IL-23 dysregulation but show distinctive genetic and immunological profiles. Therefore, they vary in their treatment responses to targeted therapies with biologicals or small molecules. In this review, we highlight the clinical presentation of skin manifestations in SpA and discuss therapeutic approaches in this interdisciplinary field.