Palmoplantar Pustulosis: Recent Advances in Etiopathogenesis and Emerging Treatments

Health-related quality of life in patients with palmoplantar pustulosis - a Swedish register study

BACKGROUND

Real-world data on health-related quality of life (HRQoL) in palmoplantar pustulosis (PPP) are scarce and few studies have analysed the generic HRQoL.

OBJECTIVES

To assess HRQoL using the generic EQ-5D instrument and the Dermatology Life Quality Index (DLQI) instrument in PPP compared to plaque psoriasis.

METHODS

Cross-sectional data from PsoReg, the Swedish National Registry for Systemic Treatment of Psoriasis (2006-2021), were examined. The study included 306 patients with PPP, out of which 22% had concomitant plaque psoriasis (n = 68), and 7041 patients with plaque psoriasis only. EQ-5D and DLQI were compared between patients with PPP and patients with plaque psoriasis, overall and stratified by sex. A subgroup analysis compared outcomes for patients with PPP vs. patients with severe plaque psoriasis (Psoriasis Area and Severity Index ≥10). Multiple regression analyses were performed to control for potential confounders (age, sex, comorbidities, lifestyle factors).

RESULTS

Patients with PPP were to a larger extent female (79% vs. 37%, p < .01) and older (mean [SD] age 59.9 [11.9] vs. 50.7 [16.0] years, p < .01) than patients with plaque psoriasis. EQ-5D values were significantly lower (worse) in patients with PPP (mean [SD] 0.622 [0.309]) compared to patients with plaque psoriasis (mean [SD] 0.715 [0.274]). No significant difference was observed compared to patients with severe plaque psoriasis (p = .237). DLQI was comparable in PPP and plaque psoriasis patients (p = .117). In the regression analyses, PPP only and PPP with plaque psoriasis were associated with lower EQ-5D values of 0.065 (p < .01) and 0.061 points (p < .10) compared to plaque psoriasis patients.

CONCLUSIONS

PPP had a substantial negative impact on patients' generic and dermatology-specific HRQoL. Patients with PPP were worse off in terms of generic HRQoL compared with patients with plaque psoriasis when controlling for the impact of potential confounders.

Exploring the effect of deucravacitinib in patients with palmoplantar pustular psoriasis

INTRODUCTION

Palmoplantar pustular psoriasis (PPPP) is a chronic inflammatory skin disorder characterized by sterile pustules on the palms and soles, significantly impacting patients' quality of life. The pathogenesis of PPPP involves intricate interactions between immune dysregulation, environmental triggers, and genetic predisposition. The treatment of PPPP is challenging, and there is a need for effective and safe treatment options for patients.

OBJECTIVE

We evaluated the efficacy and safety of deucravacitinib, a novel oral selective allosteric inhibitor of tyrosine kinase 2 (TYK2), in treating refractory PPPP.

MATERIAL AND METHODS

A retrospective analysis was conducted on five patients treated with deucravacitinib 6 mg/day, with clinical assessments at weeks 0, 4, and 16.

RESULTS

While initial worsening was observed in most patients, three showed improvement by week 16. One patient improved with the addition of methotrexate. Treatment was discontinued in two patients after week 16. Adverse effects were primarily viral and bacterial infections, and no serious adverse events occurred.

CONCLUSION

Current therapeutic options for PPPP are limited, necessitating exploration of novel treatments. Deucravacitinib's mechanism of action, targeting TYK2, could show promise in PPPP management. However, its efficacy and safety in this specific condition require further investigation through larger, randomized controlled trials.

A systematic review of recent randomized controlled trials for palmoplantar pustulosis

Background: Palmoplantar pustulosis (PPP) is a chronic inflammatory condition, that leads to significant functional impairment and reduced quality of life. Despite its low incidence, treatment options are diverse and often ineffective, necessitating a review of recent therapeutic advances.

Objective: This review aims to evaluate the efficacy and safety of recent therapeutic options for the treatment of PPP, focusing on phototherapy, systemic therapies, and biologics.

Materials and methods: A systematic literature search identified 13 studies evaluating phototherapy and systemic therapies, including biologics. Inclusion criteria focused on randomized controlled trials with participants diagnosed with PPP.

Results: Phototherapy showed success: excimer laser demonstrated high efficacy for severe disease [PPP Area and Severity Index (PPPASI)-75 of 95.0%], while psoralen plus ultraviolet A therapy with retinoids or fumaric acid esters worked well in milder disease (PPPASI-90 of 90.0 and 81.8%, respectively). Evidence supports the efficacy and safety of guselkumab, brodalumab, and apremilast over a range of disease severity (PPPASI-50 ranged from 57.4 to 78.3% at week 16). Agents including anakinra, secukinumab, spesolimab, and RIST4721 (primary outcomes not achieved) may not be first-line treatments. By targeting multiple inflammatory pathways in PPP, JAK inhibitors may be more effective than biologics in treating PPP; however, more research is needed to confirm their safety and appropriate use.

Conclusions: Multiple new treatments exist for PPP with promising results, however longer-term studies with standardized outcome reporting are needed to determine optimal treatment strategies and their comparative efficacy.

Janus kinase inhibitor tofacitinib successfully treated palmoplantar pustulosis after switching from secukinumab: A case report and review of the literature

Palmoplantar pustulosis (PPP) is a chronic inflammatory recurrent disease characterized by sterile pustules involving palms and/or feet. Presently, there are no standard recommended treatment regimens. Tofacitinib is an oral Janus kinase (JAK) inhibitor, mainly acts on JAK 1 and 3 and has been approved for the treatment of rheumatoid arthritis in adults. Herein, we present a case of a patient with PPP who did not respond to IL-17A inhibitor secukinumab but was successfully treated by the JAK inhibitor tofacitinib.

Exploratory Efficacy Evaluation of Apremilast for the Treatment of Japanese Patients with Palmoplantar Pustulosis: 32-Week Results from a Phase 2, Randomized, Placebo-Controlled Study

INTRODUCTION

Palmoplantar pustulosis (PPP) is a pruritic, painful, chronic dermatitis that greatly impacts functioning and quality of life and can be difficult to treat. Approved treatment options for PPP are limited, and many patients do not fully respond to current treatments.

METHODS

This was a randomized, double-blind, placebo-controlled, phase 2 study in Japanese patients with moderate to severe PPP and inadequate response to topical treatment. Patients were randomized 1:1 to receive apremilast 30 mg twice daily or placebo for 16 weeks followed by an extension phase where all patients received apremilast through week 32. PPP Area and Severity Index (PPPASI), modified PPPASI (which evaluates pustules and vesicles separately), and Palmoplantar Severity Index (PPSI) total scores and subscores (erythema, pustules/vesicles, and desquamation/scales) were evaluated over 32 weeks of apremilast treatment. Achievement of ≥ 50% improvement in PPPASI (PPPASI-50) was evaluated at week 16 among baseline demographic and clinical characteristic subgroups.

RESULTS

At week 16, improvements in total score and subscores for PPPASI, modified PPASI, and PPSI, as well as rates of PPPASI-50 were at least moderately greater with apremilast than placebo. Mean PPPASI total score decreased by - 68.3% from baseline to week 32 with continued apremilast treatment. At week 32, mean change from baseline in PPPASI/modified PPPASI subscores ranged from - 58.5% to - 77.0% with apremilast. At week 32, PPSI total score for physician and patient assessments decreased by - 51.3% and - 40.0%, respectively, with continued apremilast treatment. PPPASI-50 response at week 16 was greater with apremilast versus placebo in most demographic and baseline characteristic subgroups.

CONCLUSIONS

Improvements in all PPPASI and PPSI total scores and subscores observed with apremilast over 16 weeks were maintained through 32 weeks in patients with moderate to severe PPP and inadequate response to topical treatment. Rates of PPPASI-50 response at week 16 were mostly consistent across patient subgroups.

CLINICALTRIALS

GOV: NCT04057937.

Paradoxical Psoriasis in Patients Receiving Therapy with Tumor Necrosis Factor Inhibitors: Potential Pathogenic Mechanisms and the Role of Genetic Factors

TNF inhibitors (TNFi) have revolutionized the therapeutic management of various chronic immune-mediated inflammatory diseases. Despite their known benefits, these therapies are related to paradoxical adverse effects (PAEs), including paradoxical psoriasis (PP). Although the underlying mechanism remains somewhat unclear, some theories suggest that genetic factors, particularly certain single-nucleotide polymorphisms (SNPs), may play an important role. The present review aimed to research and analyze recent findings regarding the pathomechanisms involved in the appearance of PP and the association between various genetic factors and PP in individuals treated with TNFi. We performed a literature search and found that certain genes (IL23R, TNF, FBXL19, CTLA4, SLC12A8, TAP1) are strongly associated with the occurrence of PP in pediatric and adult patients during therapy with TNFi. The identification of the specific SNPs involved in the appearance of PP and other PAEs in patients treated with TNFi for various diseases and in different populations may later favor the recognition of those patients at a high risk of developing such adverse effects and could guide personalized therapeutic strategies in future years.

Associations of inflammatory cytokines with palmoplantar pustulosis: a bidirectional Mendelian randomization study

Background

Variations in circulatory cytokine levels have been observed during the onset and course of palmoplantar pustulosis (PPP); however, whether these changes are due to etiological or secondary factors is unclear. To clarify the causal relationship, we conducted a summarized-level bidirectional Mendelian randomization (MR) analysis in this study.

Methods

A FinnGen biobank genome-wide association study (GWAS) of 212,766 individuals (524 PPP patients and 212,242 controls) provided summary data for PPP, whereas genetic instrumental variables (IVs) linked to circulation cytokine levels were gathered from a GWAS of 14,824 European individuals. The inverse-variance weighted (IVW), weighted median (WME), simple mode, and MR-Egger methods were used to ascertain the changes in PPP pathogenic cytokine taxa. Sensitivity analysis, which included horizontal pleiotropy analysis, was then conducted. The reliability of the results was assessed using the leave-one-out approach and the MR Steiger test, which evaluated the strength of a causal relationship. To evaluate the reverse causality between PPP and circulating cytokine levels, a reverse MR analysis was carried out.

Results

Our study demonstrated positive associations between C-X-C motif chemokine 6 (CXCL6) and PPP (odds ratio, OR 1.257, 95%CI: 1.001-1.570, p = 0.043). C-C motif chemokine 19 (CCL19) and interleukin-6 (IL-6) were suggested to be protectively associated with the development of PPP (OR: 0.698,95% CI: 0.516-0.944, p = 0.020; OR: 0.656, 95%CI:0.437-0.985, p = 0.042). The results were steady after sensitivity and heterogeneity analyses.

Conclusion

At the genetic prediction level, we identified causally connected inflammation-related variables that contributed to the onset and development of PPP. The therapeutic options for some refractory PPP have expanded due to tailored cytokine therapy, generating fresh concepts for PPP diagnostics and mechanism investigation.

A view on the skin-bone axis: unraveling similarities and potential of crosstalk

The phrase "skin as a mirror of internal medicine," which means that the skin reflects many of the diseases of the internal organs, is a well-known notion. Despite the phenotypic differences between the soft skin and hard bone, the skin and bone are highly associated. Skin and bone consist of fibroblasts and osteoblasts, respectively, which secrete collagen and are involved in synthesis, while Langerhans cells and osteoclasts control turnover. Moreover, the quality and quantity of collagen in the skin and bone may be modified by aging, inflammation, estrogen, diabetes, and glucocorticoids. Skin and bone collagen are pathologically modified by aging, drugs, and metabolic diseases, such as diabetes. The structural similarities between the skin and bone and the crosstalk controlling their mutual pathological effects have led to the advocacy of the skin-bone axis. Thus, the skin may mirror the health of the bones and conversely, the condition of the skin may be reflected in the bones. From the perspective of the skin-bone axis, the similarities between skin and bone anatomy, function, and pathology, as well as the crosstalk between the two, are discussed in this review. A thorough elucidation of the pathways governing the skin-bone axis crosstalk would enhance our understanding of disease pathophysiology, facilitating the development of new diagnostics and therapies for skin collagen-induced bone disease and of new osteoporosis diagnostics and therapies that enhance skin collagen to increase bone quality and density.

Interleukins and Psoriasis

Psoriasis is an immune-mediated chronic inflammatory skin disease that affects 2% to 3% of the world's population. It is widely assumed that immune cells and cytokines acting together play a crucial part in the pathophysiology of psoriasis by promoting the excessive proliferation of skin keratinocytes and inflammatory infiltration. Interleukins (ILs), as a critical component of cytokines, have been closely associated with the pathogenesis and progression of psoriasis. This review summarizes the current contribution of ILs to psoriasis and describes the role each IL performs in psoriasis. Furthermore, the paper presents the therapeutic effects and application prospects of biologics developed for ILs in clinical treatment and experiments. The study aims to further the research on ILs in the treatment of psoriasis.

Successful treatment of acrodermatitis continua of Hallopeau coexisting with generalized pustular psoriasis with spesolimab: a case report

Generalized pustular psoriasis (GPP) is a rare chronic inflammatory pustular dermatosis that presents as painful erythema with sterile pustules on nonacral skin. No unified standard and guideline for the treatment of GPP has been established. Several biologics have been tried for GPP, with varying success. Acrodermatitis continua of Hallopeau (ACH) is a very rare disabling variant of pustular psoriasis characterized by sterile pustules on the fingers and toes, including the nail bed. Comparatively, treating ACH is highly challenging due to its commonly therapy-resistant disease course. The pathogenic role of IL-36 signaling axis has been currently identified in GPP development. Spesolimab, the first anti-interleukin-36 receptor biologic, has been approved for treating GPP flares and shown promising results. In view of a shared pathogenesis between GPP and ACH, specolimab may be an effective treatment for ACH. Currently, there is no case and clinical trial data exist on this condition. Therefore, this case was aim to describe real-world experience of spesolimab use in ACH coexisting with GPP. We report an Asian patient with a 16-year-history of GPP and ACH with marked pustulosis on the nail bed and onychodystrophy. He received conventional systemic regimen acitretin, cyclosporine and biologics adalimumab and secukinumab, but experienced relapse for skin lesions and refractory for nail lesions. He was then treated with a single dose of spesolimab in combination with secukinumab, which resulted in skin clearance and nearly complete resolution of nail lesions over a 32-week period. Our observation suggests that spesolimab should be considered for the treatment of ACH, especially in the patients with intractable nail lesions and concomitant GPP.

Drug survival of biologic therapies for palmoplantar pustulosis: A nationwide study

BACKGROUND

Biological therapies have established efficacy in psoriasis vulgaris. However, palmoplantar pustulosis (PPP) has proven difficult to treat, and data on drug survival in these patients remain scarce.

OBJECTIVE

To investigate drug survival of biological treatments in a nationwide cohort of patients with PPP.

METHODS

We included all patients treated for PPP with a biologic from a prospective Danish nationwide registry between 2007 and 2019. Descriptive statistics were reported. Drug survival was calculated for all patients and specified for the most frequently used biologics. Drug survival was reported as median time to discontinuation. Kaplan-Meier plots were used to visualize drug survival. Trajectories of Dermatology Life Quality Index (DLQI) scores were plotted by interpolating between the different visits with a dermatologist for each treatment course.

RESULTS

We identified 85 individual patients who received biological therapy for PPP across 194 treatment courses during follow-up. Of the included treatment courses, 151 (77.8%) were discontinued. The most frequent cause of discontinuation was ineffective response to treatment (54.3%), while 18.5% of courses were discontinued due to adverse events. The median drug survival across all therapies for PPP was 9.3 (Inter quartile range (IQR), 3.9-25.6) months. Ustekinumab demonstrated the longest median time to discontinuation of 14.6 (IQR, 9.1-51.8) months. The proportion of bio-naive patients in treatment at 12 months were according to drug 47.9% for adalimumab, 64.3% for ustekinumab and 40.0% for secukinumab. For bio-experienced, it was 58.2% adalimumab, 54.5% for ustekinumab and 51.4% for secukinumab.

CONCLUSIONS

The treatment of PPP poses significant challenges, with limited drug survival observed across all therapies regardless of prior experience with biologics. Ustekinumab demonstrated the longest median drug survival. Notably, patients discontinuing therapy due to inefficacy exhibited higher DLQI scores, highlighting the importance of personalized treatment selection and timely consideration of therapy changes when inefficacy is established.

Autoinflammatory Keratinization Diseases-The Concept, Pathophysiology, and Clinical Implications

Recent advances in medical genetics elucidated the background of diseases characterized by superficial dermal and epidermal inflammation with resultant aberrant keratosis. This led to introducing the term autoinflammatory keratinization diseases encompassing entities in which monogenic mutations cause spontaneous activation of the innate immunity and subsequent disruption of the keratinization process. Originally, autoinflammatory keratinization diseases were attributed to pathogenic variants of CARD14 (generalized pustular psoriasis with concomitant psoriasis vulgaris, palmoplantar pustulosis, type V pityriasis rubra pilaris), IL36RN (generalized pustular psoriasis without concomitant psoriasis vulgaris, impetigo herpetiformis, acrodermatitis continua of Hallopeau), NLRP1 (familial forms of keratosis lichenoides chronica), and genes of the mevalonate pathway, i.e., MVK, PMVK, MVD, and FDPS (porokeratosis). Since then, endotypes underlying novel entities matching the concept of autoinflammatory keratinization diseases have been discovered (mutations of JAK1, POMP, and EGFR). This review describes the concept and pathophysiology of autoinflammatory keratinization diseases and outlines the characteristic clinical features of the associated entities. Furthermore, a novel term for NLRP1-associated autoinflammatory disease with epithelial dyskeratosis (NADED) describing the spectrum of autoinflammatory keratinization diseases secondary to NLRP1 mutations is proposed.

Palmoplantar pustulosis with psoriatic arthritis ineffective to interleukin-17 inhibitors: two patients successfully treated with upadacitinib

Palmoplantar pustulosis (PPP) is a rare chronic pustular disease. Psoriatic arthritis (PsA) is one of the common manifestations of arthritis in PPP associated with a high burden of disease. The treatment of PPP is difficult and still in the exploratory stage. Only a few cases show that PPP complicated with arthritis have been successfully treated with janus kinase inhibition, interleukin (IL)-6 inhibitors, IL-12/23 inhibitors and tumor necrosis factor inhibitors. Here we reported that two patients were diagnosed as PPP with PsA and initially treated with IL-17 inhibitors. One case was only partially relieved, and the other case had severe paradoxical reaction in the trunk. The joint and skin condition of two patients had been significantly improved without reported adverse reactions after 18 weeks treatment with upadacitinib, which support upadacitinib may be a potential option for patients with PPP combined PsA.

Photodynamic therapy for palmoplantar pustulosis: A case report

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin disease characterised by sterile, relapsing pustules on erythematous, scaly backgrounds on the palms and soles. PPP impairs quality of life and is notoriously challenging to manage. Here, we presented the case of a 79-year-old male who suffered from recalcitrant PPP for 9 years and responded not well to halometasone, acitretin capsules and oral Chinese traditional medicine. The patient showed improvement with a great reduction of erythema, scales, pustules after 5 sessions of 5-aminolevulinic acid photodynamic therapy (ALA-PDT), suggesting that ALA-PDT could be a potentially safe and effective therapeutic option for PPP.

The role of the interleukin-36 axis in generalized pustular psoriasis: a review of the mechanism of action of spesolimab

Generalized pustular psoriasis (GPP) is a rare, chronic, inflammatory skin disorder characterized by recurrent flares associated with skin erythema, desquamation, and widespread superficial sterile pustules, which may be severe ("lakes of pus"). Systemic symptoms are often present, including malaise, fever, and skin pain. In GPP, innate immune responses are driven by abnormal activation of the interleukin (IL)-36-chemokine-neutrophil axis and excessive neutrophil infiltration. This review highlights the IL-36 pathway in the context of the IL-1 superfamily and describes how unopposed IL-36 signaling can lead to the development of GPP. Targeted inhibition of the IL-36 receptor (IL-36R) is an attractive therapeutic strategy in the treatment of GPP, including flare prevention and sustained disease control. Spesolimab is a first-in-class, humanized, monoclonal antibody that binds specifically to the IL-36R and antagonizes IL-36 signaling. Spesolimab was approved by the US Food and Drug Administration in September 2022 to treat GPP flares in adults and was subsequently approved for GPP flare treatment in other countries across the world. Anti-IL-36R therapy, such as spesolimab, can mitigate flares and address flare prevention in GPP, presumably through rebalancing IL-36 signaling and modulating the pro-inflammatory response of the downstream effectors.

The Epidemiology of Palmoplantar Pustulosis: An Analysis of Multiple Health Insurance Claims and Electronic Health Records Databases

BACKGROUND

Palmoplantar pustulosis (PPP) is a chronic inflammatory condition characterized by sterile pustules on the palms and soles. This study evaluated the epidemiology of PPP using claims and electronic health record (EHR) databases.

METHODS

Patients coded for PPP in the United States (US) and Japan from 2016 to 2020 were identified. Several PPP definitions were evaluated; the specific definition (≥ 2 visits coded for PPP, the second 31-730 days after diagnosis) was chosen for characterizing PPP epidemiology. Baseline characteristics and pre- and post-diagnosis treatments were summarized. Prevalence and incidence rates were analyzed by calendar year, sex, age, and database.

RESULTS

Prevalence and incidence of PPP were higher in Japan than the US. PPP prevalence increased over time. PPP occurred predominantly in adulthood and was more common among women. Features of metabolic syndromes, anxiety, and depression were more common among US PPP patients. Consistently high baseline use of anti-bacterial, anti-inflammatory/anti-rheumatic, and obstructive airway disease treatments was observed among PPP patients. Potential miscoding or misclassification of PPP limited this analysis. Prevalence estimates from databases may differ from field- and population-based approaches.

CONCLUSIONS

The burden of PPP was greater in Japan than in the US. Additional studies are needed to further elucidate PPP epidemiology worldwide.

Characteristics and Burdens of Disease in Patients from Beijing with Generalized Pustular Psoriasis and Palmoplantar Pustulosis: Multicenter Retrospective Cohort Study Using a Regional Database

BACKGROUND AND OBJECTIVE

Pustular psoriasis is a chronic and recurrent autoimmune disease, although little is known about the disease burden of pustular psoriasis in China. We analyzed the characteristics and disease burdens of patients from Beijing who had generalized pustular psoriasis (GPP) or palmoplantar pustulosis (PPP).

METHODS

This multicenter retrospective cohort study used a regional electronic health database that covered 30 public hospitals in Beijing. From June 2016 to June 2021, all patients with a diagnosis of GPP, PPP, or psoriasis vulgaris (PV) were identified by International Statistical Classification of Diseases and Related Health Problems, 10th Revision codes. The GPP and PPP cohorts were separately matched with patients with PV in a 3:1 ratio for comparisons. Demographic data, clinical characteristics, healthcare resource utilization, and costs were collected. Descriptive and comparative analyses were used to compare the cohorts.

RESULTS

There were 744 patients with GPP (46.8% men; age 42.14 ± 21.47 years) and 4808 patients with PPP (35.5% men; age 51.65 ± 16.12 years); 14.5% of patients with GPP had concomitant PV and 7.5% of patients with PPP had concomitant PV. Relative to matched patients with PV, patients with GPP had a higher prevalence of erythrodermic psoriasis (5.9% vs 0.4%, p < 0.0001), psoriatic arthritis (3.1% vs 1.5%, p = 0.007), and organ failure (1.1% vs 0.2%, p = 0.002). Relative to matched patients with PV, patients with PPP had a higher prevalence of cerebrovascular disease (4.7% vs 1.2%, p < 0.0001), thyroid dysfunction (3.9% vs 3.3%, p = 0.035), and type 2 diabetes mellitus (6.8% vs 5.9%, p = 0.030). More patients with GPP than patients with PV received systemic non-biological agents (27.9% vs 3.3%, p < 0.0001) and biologic agents (4.8% vs 2.0%, p = 0.010). More patients with PPP than patients with PV received topical agents (50.9% vs 34.7%, p < 0.0001) and systemic non-biological agents (17.8% vs 2.7%, p < 0.0001). More patients with GPP than patients with PV required inpatient hospitalization (22.0% vs 7.8%, p < 0.0001). Hospitalization stay was longer in patients with GPP than patients with PV (11.72 ± 0.45 vs 10.38 ± 0.45 days, p = 0.022). More patients with PPP than patients with PV had emergency visits (16.3% vs 12.8%, p < 0.0001). The GPP and PPP cohorts and their matched PV cohorts had no significant differences in costs. However, patients with PPP had lower outpatient costs than patients with PV (368.20 ± 8.19 vs 445.38 ± 5.90 Chinese Yuan per patient per month, p < 0.0001).

CONCLUSIONS

Patients from Beijing with GPP and PPP had higher disease burdens than matched PV cohorts, including the prevalence of comorbidities, healthcare resource utilization, and medication burden. However, the economic burden of pustular psoriasis was similar to that of PV. Practical and specific therapies are needed to reduce the burdens of pustular psoriasis.

Secukinumab-Induced Alopecia Areata Successfully Treated with Tofacitinib in a Patient with Palmoplantar Pustulosis

Secukinumab, a monoclonal antibody targeting interleukin-17 (IL-17), has exhibited encouraging results in the therapeutic management of palmoplantar pustulosis (PPP). The development of alopecia areata (AA) is closely related to IL-17, and IL-17A inhibitors were considered as a potential treatment modality. Therefore, the development of AA during secukinumab treatment for PPP is a rare adverse event that has been rarely reported worldwide. Here we report a 35-year-old female patient with PPP who developed AA after completing the induction period of secukinumab treatment. Discontinuing secukinumab and initiating treatment with tofacitinib resulted in a significant improvement in both PPP and AA. The emergence of AA in this patient can be attributed to paradoxical skin reactions associated with IL-17 inhibitors. Tofacitinib appears to alleviate biologic-induced AA during PPP syndrome treatment.

Palmoplantar Pustulosis: A Systematic Review of Risk Factors and Therapies

Palmoplantar pustulosis (PPP) is a chronic, relapsing, inflammatory disease that can occur alone or in association with arthritis. There is still controversy about whether it should be separated from psoriasis or classified as pustular psoriasis. Furthermore, drug-induced paradoxical PPP is a special variant of PPP that differs from classic PPP in several ways. Treatment of PPP is still challenging, and there are a number of treatment-resistant cases. This review summarizes the risk factors for the development of PPP and the currently available treatment modalities. Female sex, smokers or ex-smokers, obesity, thyroid dysfunction, and treatment with a tumor necrosis factor (TNF)-α inhibitor have been identified as risk factors for the disease's development, severity, and course. Topical treatments and phototherapy are effective for some patients and are used as a first-line or adjuvant treatment modality. Conventional treatments including retinoids and fumaric acid show good effects and can increase the efficacy of treatment with psoralen + ultraviolet light therapy (PUVA). Ciclosporin is fast acting, but relapse mostly occurs immediately after cessation. TNF-α inhibitors are efficient, and an even better response can be achieved with IL-17 and IL-23 blockers as well as apremilast. The effect of Janus kinase inhibitors seems to be promising according to case reports, but further investigations with larger cohorts are needed.

Efficacy and Safety of Apremilast for the Treatment of Japanese Patients with Palmoplantar Pustulosis: Results from a Phase 2, Randomized, Placebo-Controlled Study

BACKGROUND

Palmoplantar pustulosis (PPP) is a pruritic, painful, recurrent, and chronic dermatitis with limited therapeutic options.

OBJECTIVE

To evaluate the efficacy and safety of apremilast for the treatment of Japanese patients with PPP and inadequate response to topical treatment.

METHODS

This phase 2, randomized, double-blind, placebo-controlled study enrolled patients with Palmoplantar Pustulosis Area and Severity Index (PPPASI) total score ≥ 12 and moderate or severe pustules/vesicles on the palm or sole (PPPASI pustule/vesicle severity score ≥ 2) at screening and baseline with an inadequate response to topical treatment. Patients were randomized (1:1) to apremilast 30 mg twice daily or placebo for 16 weeks, followed by a 16-week extension phase during which all patients received apremilast. The primary endpoint was achievement of PPPASI-50 response (≥ 50% improvement from baseline in PPPASI). Key secondary endpoints included change from baseline in PPPASI total score, Palmoplantar Pustulosis Severity Index (PPSI), and patient's visual analog scale (VAS) for PPP symptoms (pruritus and discomfort/pain).

RESULTS

A total of 90 patients were randomized (apremilast: 46; placebo: 44). A significantly greater proportion of patients achieved PPPASI-50 at week 16 with apremilast versus placebo (P = 0.0003). Patients receiving apremilast showed greater improvement in PPPASI at week 16 versus placebo (nominal P = 0.0013), as well as PPSI and patient-reported pruritus and discomfort/pain (nominal P ≤ 0.001 for all). Improvements were sustained through week 32 with apremilast treatment. The most common treatment-emergent adverse events included diarrhea, abdominal discomfort, headache, and nausea.

CONCLUSIONS

Apremilast treatment demonstrated greater improvements in disease severity and patient-reported symptoms versus placebo at week 16 in Japanese patients with PPP with sustained improvements through week 32. No new safety signals were observed.

CLINICALTRIALS

GOV: NCT04057937.

Challenges and Future Trends in the Treatment of Psoriasis

Psoriasis is a chronic inflammatory skin disorder, and current treatments include topical therapies, phototherapy, systemic immune modulators, and biologics, aiming to alleviate symptoms and improve quality of life. However, challenges persist, such as adverse effects, treatment resistance, high costs, and variability in response among individuals. The future of psoriasis treatment shows promising emerging trends. New biologic agents targeting novel pathways, such as interleukin 23 inhibitors like mirikizumab, offer enhanced efficacy. Small molecule inhibitors like RORγt inhibitors and ROCK2 inhibitors provide additional treatment options. Combination therapies, including biologics with methotrexate, may improve treatment response. Advancements in topical treatments utilizing microneedles and nanoparticle-based carriers can enhance drug delivery and improve therapeutic outcomes. Biomarkers and multi-omics technologies hold potential for personalized treatment approaches, thus aiding in diagnosis, predicting treatment response, and guiding therapeutic decisions. Collaboration among researchers, clinicians, and industry stakeholders is crucial to translating these scientific breakthroughs into clinical practice. By addressing current challenges and exploring these promising trends, we can optimize psoriasis management and improve the lives of those affected by this chronic condition.

Refractory Palmoplantar Pustulosis Successfully Treated with JAK Inhibitor Tofacitinib: A Case Series

Background

Palmoplantar pustulosis (PPP) is a common chronic and recurrent skin disease of the palms and soles with significant pain, mental distress, and functional disability. PPP is challenging to treat and usually requires prolonged management. Therapy resistance and frequent relapse discourages patients from follow-up. No unified standard and no published therapeutic guidelines have yet been defined on PPP treatment. In general, all therapeutic options known for autoimmune diseases, psoriasis in particular, have been tested in PPP. Tofacitinib, an oral JAK inhibitor, has been approved for the treatment of rheumatoid arthritis and shows promise in the treatment of moderate-to-severe plaque psoriasis. However, no clinical trials or case reports have been conducted to confirm the efficacy of tofacitinib in palmoplantar pustulosis.

Methods

Six in total with 6 PPP patient, aged 42-58 years were recruited according to the inclusion and exclusion criteria. Patient characteristics, including triggering factors, concomitant diseases, and previous therapeutic drugs, were investigated. All patients experienced a lack of response to topical drugs and at least one systemic agent. During treatment, visits were scheduled at the start of treatment and at 2, 4, and 12 weeks, and efficacy was assessed using the PPP ASI and PPP PGA.

Results

Our six patients showed an excellent response to tofacitinib as all patients did achieve at least 50% reduction and half of our patients with more than 80% reduction in PPPASI after 4 weeks treatment; at week 12, 5 (83.3%) patients had 80% reduction in PPPASI with no serious adverse events were reported.

Conclusion

The JAK inhibitor tofacitinib is a promising treatment for refractory palmoplantar pustulosis that requires further clinical observation and research.

Deficiency of interleukin-36 receptor antagonist (DITRA): An analysis of 58 Chinese patients in a tertiary hospital in Taiwan

DITRA, acronym for deficiency of interleukin-36 receptor antagonist (IL36RN), leads to unopposed pro-inflammatory signalling which typically manifests as pustular psoriasis. In Asian patients, c.115 + 6 T > C mutation is the most common and important single-nucleotide variant in DITRA. We present the largest case series consisting of 58 DITRA patients carrying heterozygous or homozygous c.115 + 6 T > C mutation. The mean age of onset (±SD) was 20.74 (±20.86), and the median age of onset was 13 years old. Twelve patients (20.7%) had disease onset before the age of two. Twenty-two patients (37.9%) had disease onset between the ages of 2-18. Main clinical phenotype was generalized pustular psoriasis (GPP) with systemic symptoms (33 patients, 56.9%), followed by acrodermatitis continua of Hallopeau (ACH) (16 patients, 27.6%). Nearly half of our patients (27 patients, 46.6%) ever had ACH, and only three of them are free of ACH currently, which indicates that the development of ACH is relatively persistent and irreversible. Thirty-four patients (58.6%) had recurrent GPP and 29 patients (50%) have been admitted due to GPP flare. Compared to those with heterozygous (C/T) mutation, more patients carrying homozygous mutation (C/C) have recurrent episodes of GPP (C/T vs. C/C: 25.53 vs. 76.47%, p = 0.0367). Two patients with squamous cell carcinomas arising from the pustular psoriasis skin lesions were noted. Two patients had elevated serum IgG4 levels.

Variables associated with joint involvement and development of a prediction rule for arthritis in patients with psoriasis. An analysis of the Italian PsoReal database

BACKGROUND

Limited data exist to predict the development of psoriatic arthritis (PsA) in patients with psoriasis (PsO).

OBJECTIVE

To analyze factors associated with incident PsA in patients with PsO, and to develop a predictive algorithm for progression to arthritis using a full set of variables and a restricted one applicable to administrative data.

METHODS

Cohort study within the PsoReal registry in Italy. Multivariable generalized linear models were used to assess factors associated with PsA and to derive a predictive model.

RESULTS

Among 8895 patients, 226 PsA cases were identified (incidence 1.9 per 100 patient-years). Independent predictors in the full model were as follows: female sex, age 40 to 59 years, body mass index ≥ 25, chronic-plaque PsO features, presence of palmoplantar pustulosis, hospitalization for PsO in the last 5 years, and previous use of systemic PsO therapy (area under the receiver operating characteristic curve = 0.74). Female sex, age 40 to 59 years, hospitalization for PsO, and previous use of systemic PsO therapy were independent predictors in the restricted model (area under the receiver operating characteristic curve = 0.72).

LIMITATIONS

Lack of other potential predictors for PsA.

CONCLUSION

Our models could be used by clinicians and health authorities when planning intervention and population surveillance. Future studies should confirm our models using larger datasets and additional variables.

Efficacy of biologic agents for palmoplantar psoriasis: a systematic review and network meta-analysis

BACKGROUND

Palmoplantar psoriasis (PP) represents a localized type of disease. While controversy over its' classification exists, a hyperkeratotic type, a pustular type and palmoplantar pustulosis (PPP) have been recognized. PP management is regularly supported by biologic agents. Our study aimed to review and synthesize available data regarding the efficacy of approved biologics for PP and PPP.

RESEARCH DESIGN AND METHODS

A literature search was conducted in PubMed, CENTRAL, Scopus, and ClinicalTrilas.gov. Utilizing random-effects inverse-variance frequentist network meta-analyses (NMAs), we ranked interventions. The proportion of participants with cleared skin was the primary outcome. Fifty and 75% improvement in palmoplantar psoriasis area severity index (PPASI) were also explored (PPASI50, PPASI75).

RESULTS

In total, 15 randomized controlled trials (RCTs) exploring the efficacy of on-label adalimumab, bimekizumab, etanercept, guselkumab, infliximab, ixekizumab, secukinumab, and ustekinumab were included. Data for PP were synthesized. Every biologic agent examined, except from infliximab, outperformed placebo. On-label secukinumab exhibited the highest probability of inducing complete resolution. Ixekizumab and infliximab ranked best on inducing PPASI50 and PPASI75. Our review supports that guselkumab is effective for PPP.

CONCLUSIONS

Secukinumab, ixekizumab and infliximab are effective for PP. Research is warranted to produce evidence about the efficacy of biologics in PP and PPP.

Comorbidities in palmoplantar pustulosis: a Swedish population-based register study

This study investigated the comorbidity burden of Swedish patients with palmoplantar pustulosis (PPP) vs. the general population and patients with psoriasis vulgaris (PV). We found a significantly higher comorbidity burden in patients with PPP compared with the general population, represented by higher odds for disease across different categories (metabolic, cerebrovascular, cardiovascular, psychiatric). Although patients with PPP and PV showed similar comorbidity burdens overall, the comorbidity profiles differed significantly. Comorbidities such as type 2 diabetes and chronic obstructive pulmonary disorder, which showed both high prevalence (&gt; 5%) in PPP and higher odds than PV, may be of particular importance for the specific comorbidity burden of PPP.

An update on therapeutic options for palmoplantar pustulosis: a narrative review and expert recommendations

INTRODUCTION

Palmoplantar pustulosis (PPP) is a chronic inflammatory skin disease belonging to the localized form of pustular psoriasis. It is characterized by sterile pustule formation in palms and soles and a recurrent disease course. Although we have many treatments for PPP, there is no authoritative guidance.

AREAS COVERED

A thorough search of PubMed was conducted to identify studies in PPP from 1973 onwards, with additional references to specific articles. Any treatment methods were outcomes of interest, including topical treatment, systemic treatment, biologics, other targeted treatments, phototherapy, and tonsillectomy.

EXPERT OPINION

Topical corticosteroids are suggested as first-line therapy. Oral acitretin has become the most applied systemic retinoid recommended in PPP without joint involvement. For patients with arthritis, immunosuppressants like cyclosporin A and methotrexate are more recommended. UVA1, NB-UVB, and 308-nm excimer laser are effective phototherapy options. The combinations of topical or systemic agents and phototherapy may enhance the efficacy, particularly in recalcitrant cases. Secukinumab, ustekinumab, and apremilast are the most investigated targeted therapies. However, heterogeneous reported outcomes in clinical trials provided low-to-moderate quality evidence of their efficacy. Future studies are required to address these evidence gaps. We suggest managing PPP based on the acute phase, maintenance phase, and comorbidities.

Targeting IL-36 in Inflammatory Skin Diseases

Interleukin (IL)-36 cytokines are members of the IL-1 superfamily of cytokines. IL-36 cytokines are composed of three agonists (IL-36α, IL-36β, and IL-36γ) and two antagonists (IL-36 receptor antagonist [IL36Ra] and IL-38). These work in innate and acquired immunity and are known to contribute to host defense and to the pathogenesis of autoinflammatory diseases, autoimmune diseases, and infectious diseases. In the skin, IL-36α and IL-36γ are mainly expressed by keratinocytes in the epidermis, although they are also produced by dendritic cells, macrophages, endothelial cells, and dermal fibroblasts. IL-36 cytokines participate in the first-line defense of the skin against various exogenous assaults. IL-36 cytokines play significant roles in the host defense system and in the regulation of inflammatory pathways in the skin, collaborating with other cytokines/chemokines and immune-related molecules. Thus, numerous studies have shown IL-36 cytokines to play important roles in the pathogenesis of various skin diseases. In this context, the clinical efficacy and safety profiles of anti-IL-36 agents such as spesolimab and imsidolimab have been evaluated in patients with generalized pustular psoriasis, palmoplantar pustulosis, hidradenitis suppurativa, acne/acneiform eruptions, ichthyoses, and atopic dermatitis. This article comprehensively summarizes the roles played by IL-36 cytokines in the pathogenesis and pathophysiology of various skin diseases and summarizes the current state of research on therapeutic agents that target IL-36 cytokine pathways.

A Review of the Clinical Trial Landscape in Psoriasis: An Update for Clinicians

As our understanding of the pathogenesis of psoriasis has evolved over the past two decades, so has the number of treatment options. The introduction of biologic agents targeting specific cytokines in the interleukin (IL)-23/IL-17 pathway has proven successful in promoting skin clearance among patients. However, their use is often limited owing to cost, parenteral administration, and possible reduced efficacy over time. Topical therapies have also seen limited advancement, with agents such as corticosteroids and vitamin D derivatives remaining the mainstay of treatment, despite side effects limiting their long-term use. New therapeutic agents are needed to improve disease management for patients. In this review, we summarize pipeline and recently approved therapies undergoing clinical trials for psoriasis during a 12-month search period (30 June 2021 to 30 June 2022) using ClinicalTrials.gov. New-generation biologics and oral small molecules in phase II or III development were included, and pivotal data identified through various search modalities (PubMed, conference presentations, etc.) evaluating each drug candidate will be discussed. Topical therapies will also be discussed in line with recent US Food and Drug Administration approvals. As new therapies continue to enter the treatment landscape, long-term data and comparative trials will be needed to better understand their place among existing therapeutic agents.

Updates and Proposed Diagnostic Approach to Psoriasiform Dermatoses

Psoriasiform dermatoses represent a wide array of skin diseases commonly encountered by clinicians and pathologists. While they may present a diagnostic challenge, thorough observation coupled with proper interpretation of subtle additional clinical or histopathologic features provide clues to the correct diagnosis. In this review, we provide updates on emerging entities and develop a systemic approach to establish the pathologic diagnosis, with emphasis on the importance of clinicopathologic correlation.

Relapse of Palmoplantar Pustulosis Following COVID-19 Vaccination

Palmoplantar pustulosis (PPP) is a rare chronic pustular condition that affects the palms and soles. Smoking and focal infections and dental metal allergies are risk factors for PPP development. Here we report a case of a 60-year-old woman who experienced a relapse of PPP after receiving the COMIRNATY vaccine against COVID-19. The patient relapsed after being in remission for seven years. This article shows the possible implications of COVID-19 vaccination related to the relapse of previous diseases and stresses the importance of careful observation of post-vaccination occurrences of skin eruptions, especially in patients having a history of PPP.

Exceptional response of skin symptoms to secukinumab treatment in a patient with SAPHO syndrome: Case report and literature review

RATIONALE

SAPHO syndrome is a rare clinical entity characterized by a wide range of dermatological and musculoskeletal manifestations. Treatment strategies are not standardized. Palmoplantar pustulosis (PPP) is the most common rash in patients with SAPHO syndrome.

PATIENT CONCERNS

A 24-year-old Chinese woman with no relevant medical or familial history had a 1-year history of cutaneous lesions with PPP and pain in the sternoclavicular joint.

DIAGNOSIS

Based on the diagnostic criteria for SAPHO syndrome proposed by Nguyen et al in 2012, we diagnosed SAPHO syndrome with severe PPP as the predominant manifestation.

INTERVENTIONS

Due to the limited therapeutic efficacy of methotrexate and cyclosporin, we started therapy with subcutaneous secukinumab 150 mg weekly for the first month, then 150 mg monthly thereafter.

OUTCOMES

After 4 weeks of secukinumab administration, the patient showed significant remission of pustular skin lesions, with almost no joint pain and no adverse reaction. Complete remission of skin symptoms was achieved after 3 months. Joint pain and adverse events have not reoccurred in follow-up thus far.

CONCLUSIONS

In patients with SAPHO syndrome, we recommend personalized treatment, which may have excellent therapeutic efficacy in those with PPP or severe skin symptoms. Although data related to the use of IL-17 blockers for SAPHO syndrome are very limited, secukinumab provides a novel therapeutic option, especially for patients with PPP and severe skin lesions. Further prospective studies are needed to support our findings.

Involvement of Molecular Mechanisms between T/B Cells and IL-23: From Palmoplantar Pustulosis to Autoimmune Diseases

Palmoplantar pustulosis (PPP) is a disease that causes recurrent blisters and aseptic pustules on the palms and soles. It has been suggested that both innate and acquired immunity are involved. In particular, based on the tonsils and basic experiments, it has been assumed that T and B cells are involved in its pathogenesis. In addition, the results of clinical trials have suggested that IL-23 is closely related to the pathogenesis. This review describes PPP and the genetic background, the factors involved in the onset and exacerbation of disease and its relation to the molecular mechanism. In addition, we describe the usefulness of biological therapy and its implications in relation to the importance in pathology, the pathogenesis of PPP, the importance of the role of the IL-23-Th17 axis and IL-36 in PPP. Furthermore, we describe an animal experimental model of PPP, the efficacy and mechanism of action of guselkumab, an anti-IL-23 antibody, the latest research, and finally the possibility for it to be effective for other autoimmune diseases.

Practice Patterns of Palmoplantar Pustulosis: Patient Demographics and Treatment Options

Background

Palmoplantar pustulosis (PPP) is a chronic skin condition characterized by sterile pustules on the palms and soles. This condition is more commonly reported among women and smokers causing considerable discomfort and interference with daily activities. Although there are various off-label treatment options available for PPP, there remains a demand to identify more effective and safer treatments.

Objective

To review the patient demographics and treatment patterns of our PPP patient population.

Methods

A retrospective chart review was performed at a dermatology office with two locations in Ontario, Canada.

Results

We identified 71 adult PPP patients. A third of patients did not return for follow up after diagnosis. Among those who returned for follow-up, 20% were managed with topical therapy alone. Of our patients who took systemic treatment for PPP, apremilast, followed by ustekinumab and guselkumab, had the greatest retention of therapy.

Conclusion

Targeting PDE4, IL-12/23 and IL-23 provided some benefit for our patients with PPP leading to greatest retention of therapy over time. Further investigation is required into the cause for high no-show rates and the search for effective and safe treatment options.

Line-field confocal optical coherence tomography: a new tool for non-invasive differential diagnosis of pustular skin disorders

Background

The spectrum of pustular skin disorders (PSD) is large and particularly challenging, including inflammatory, infectious and amicrobial diseases. Moreover, although pustules represent the unifying clinical feature, they can be absent or not fully developed in the early stage of the disease. The line‐field confocal optical coherence tomography (LC‐OCT) is a recently developed imaging technique able to perform a non‐invasive, in vivo, examination of the epidermis and upper dermis, reaching very high image resolution and virtual histology.

Objectives

We aimed to investigate the potentialities of LC‐OCT in the non‐invasive differential diagnosis of a series of 11 PSD with different aetiology, microscopic features, body location and incidence rates.

Materials and Methods

Complete LC‐OCT imaging (i.e. 2D/3D frames, videos) was performed on a total of 19 patients (10 females and 9 males) aged between 35 and 79 years. Images were blindly evaluated and compared with corresponding histopathologic findings.

Results

The LC‐OCT imaging was able to detect with high accuracy the pustule structure including shape, margins, morphology and cellular content, along with peculiar epidermal and adnexal alterations in each condition, including: Acute Generalized Exanthematous Pustulosis, Generalized pustular psoriasis, Generalized pustular figurate erythema, Subcorneal Pustular Dermatosis, Intraepidermal IgA pustulosis, Palmoplantar pustulosis, Palmoplantar pustular psoriasis. Herpetic whitlow, Acrodermatitis continua of Hallopeau, Vesicopustular Sweet syndrome and Vesicopustular Eosinophilic cellulitis, with pustular appearance, were also compared.

Conclusions

The new LC‐OCT can represent a rapid, non‐invasive and painless tool which can help differentiating among PSD of different aetiology and microscopic morphology in clinical mimickers in daily practice.

Narrative Review of the Emerging Therapeutic Role of Brodalumab in Difficult-to-Treat Psoriasis

Psoriatic involvement in areas of the body such as nails, palms and soles (palmoplantar), and scalp is associated with dramatically negative effects on quality of life relative to involvement elsewhere in the body. Although numerous evidence-based studies demonstrate the efficacy of biologics for overall skin clearance in moderate-to-severe plaque psoriasis (including tumor necrosis factor α [TNFα] inhibitors and interleukin [IL]-17A, IL-12/IL-23, IL-23, IL-17F, and IL-17A/F inhibitors), large, randomized, placebo-controlled clinical studies of psoriasis with nail, palmoplantar, and scalp involvement are needed to better inform decision-making in clinical practice. Moreover, biologic failure caused by drug ineffectiveness is a common occurrence in patients who do not respond, lose response, or are intolerant to treatment. Brodalumab is a fully human IL-17 receptor A antagonist that demonstrates high rates of skin clearance among the latest generation of biologic therapies for treatment of moderate-to-severe psoriasis. This review summarizes current literature on the efficacy of brodalumab and other therapies in difficult-to-treat psoriasis including psoriasis in difficult-to-treat locations (such as psoriasis with nail, palmoplantar, or scalp involvement) and psoriasis in patients whose disease did not respond to other biologics.

Symptom Experience and Content Validity of the Psoriasis Symptom Scale (PSS) in Patients with Generalized Pustular Psoriasis (GPP)

Introduction

We sought to understand key symptoms of generalized pustular psoriasis (GPP) and to confirm the relevance to patients and content validity of the Psoriasis Symptom Scale (PSS) in GPP.

Methods

A targeted literature review and clinical expert interviews were conducted as background research. Patients were interviewed individually (involving concept elicitation and cognitive interviews), and a separate patient workshop was conducted to determine disease-specific symptoms of importance.

Results

Seven participants with moderate (n = 4), severe (n = 2), and mild (n = 1) GPP and clinician diagnosis were interviewed. During concept elicitation, all participants indicated that pustules may underlie other symptoms. Symptoms reported by all patients were pain, redness, itch, burning, and discomfort. The PSS symptoms of pain, itching, burning, and redness were reported by ≥ 86% of patients as most frequently experienced. Upon debriefing, the PSS was well understood. Relevance and importance of these symptoms was confirmed in the GPP patient workshop.

Conclusion

Participant feedback found the PSS measure to be relevant and easy to understand. The symptoms included in the instrument, pain, redness, itch, and burning, were most frequently reported, important, and well understood by patients. Study results provided support for the content validity of the PSS for use as endpoints in GPP clinical trials.

Generalized pustular psoriasis (GPP) is a severe rare disease, including redness and boils that sometimes come with fever and other general symptoms. This study asked patients with GPP about their key symptoms, and whether the Psoriasis Symptom Scale (PSS) is relevant to them as patients. The PSS is a questionnaire with the symptoms pain, itching, burning, and redness. We searched the literature and interviewed clinical experts to guide the patient interviews. Patients were recruited through clinical sites and the National Psoriasis Foundation (NPF). The interviews discussed GPP symptoms and the PSS questionnaire. Patients with GPP were also asked about commonly experienced symptoms in a workshop. Most patients had moderate to severe GPP. Patients in both the interviews and workshop described experiencing pain, redness, itch, burning, and discomfort with their boils. During interviews, the patients said the PSS questionnaire was easy to understand. Patients in the workshop also found the PSS to be relevant and easy to understand. Patients agreed the symptoms in the PSS, pain, redness, itch, and burning, were common and important. Study results support the PSS for use with patients in clinical trials.

Risks of Comorbidities in Patients With Palmoplantar Pustulosis vs Patients With Psoriasis Vulgaris or Pompholyx in Korea

Importance

Palmoplantar pustulosis (PPP) has been reported to be accompanied by systemic conditions. However, the risks of comorbidities in patients with PPP have rarely been evaluated.

Objective

To assess the risks of comorbidities in patients with PPP compared with patients with psoriasis vulgaris or pompholyx.

Design, Setting, and Participants

This nationwide population-based cross-sectional study used data from the Korean National Health Insurance database and the National Health Screening Program collected from January 1, 2010, to December 31, 2019. Data were analyzed from July 1, 2020, to October 31, 2021. Korean patients diagnosed with PPP, psoriasis vulgaris, or pompholyx who visited a dermatologist between January 1, 2010, and December 31, 2019, were enrolled.

Exposures

Presence of PPP.

Main Outcomes and Measures

The risks of comorbidities among patients with PPP vs patients with psoriasis vulgaris or pompholyx were evaluated using a multivariable logistic regression model.

Results

A total of 37 399 patients with PPP (mean [SD] age, 48.98 [17.20] years; 51.7% female), 332 279 patients with psoriasis vulgaris (mean [SD] age, 47.29 [18.34] years; 58.7% male), and 365 415 patients with pompholyx (mean [SD] age, 40.92 [17.63] years; 57.4% female) were included in the analyses. Compared with patients with pompholyx, those with PPP had significantly higher risks of developing psoriasis vulgaris (adjusted odds ratio [aOR], 72.96; 95% CI, 68.19-78.05; P < .001), psoriatic arthritis (aOR, 8.06; 95% CI, 6.55-9.92; P < .001), ankylosing spondylitis (aOR, 1.91; 95% CI, 1.61-2.27; P < .001), type 1 diabetes (aOR, 1.33; 95% CI, 1.16-1.52; P < .001), type 2 diabetes (aOR, 1.33; 95% CI, 1.29-1.38; P < .001), Graves disease (aOR, 1.25; 95% CI, 1.11-1.42; P < .001), Crohn disease (aOR, 1.63; 95% CI, 1.11-2.40; P = .01), and vitiligo (aOR, 1.87; 95% CI, 1.65-2.12; P < .001) after adjusting for demographic covariates. The risks of ankylosing spondylitis (aOR, 1.37; 95% CI, 1.16-1.62; P < .001) and Graves disease (aOR, 1.40; 95% CI, 1.23-1.58; P < .001) were significantly higher among patients with PPP vs psoriasis vulgaris. However, the risks of psoriatic arthritis (aOR, 0.54; 95% CI, 0.47-0.63; P < .001), systemic lupus erythematosus (aOR, 0.67; 95% CI, 0.46-0.97; P = .04), Sjögren syndrome (aOR, 0.70; 95% CI, 0.50-0.96; P = .03), systemic sclerosis (aOR, 0.29; 95% CI, 0.11-0.77; P = .01), vitiligo (aOR, 0.53; 95% CI, 0.47-0.60; P < .001), and alopecia areata (aOR, 0.88; 95% CI, 0.81-0.95; P = .001) were significantly lower among those with PPP vs psoriasis vulgaris.

Conclusions and Relevance

The results of this cross-sectional study suggest that patients with PPP have an overlapping comorbidity profile with patients with psoriasis vulgaris but not patients with pompholyx. However, the risks of comorbidities among patients with PPP may be substantially different from those among patients with psoriasis vulgaris.

Low-Density Granulocytes in Immune-Mediated Inflammatory Diseases

Low-density granulocytes (LDGs), a distinct subset of neutrophils that colocalize with peripheral blood mononuclear cells after density gradient centrifugation, have been observed in many immune-mediated diseases. LDGs are considered highly proinflammatory because of enhanced spontaneous formation of neutrophil extracellular traps, endothelial toxicity, and cytokine production. Concomitantly, increased numbers of LDGs are associated with the severity of many immune-mediated inflammatory diseases. Recent studies, with the help of advanced transcriptomic technologies, demonstrated that LDGs were a mixed cell population composed of immature subset and mature subset, and these two subsets showed different pathogenic features. In this review, we summarize the current knowledge on the composition, origin, and pathogenic properties of LDGs in several immune-mediated inflammatory diseases and discuss potential medical interventions targeting LDGs.

Therapeutic potential of targeting IL-1 family cytokines in chronic inflammatory skin diseases

The interleukin-1 (IL-1) family of cytokines is a central regulator of a myriad of immunological responses. It comprises several cytokines, including those belonging to the IL-1, IL-36 and IL-18 subfamilies, as well as IL-33. The IL-1 family primarily plays a role in orchestrating innate immune responses but also in adaptive immunity. Increased interest in the IL-1 family occurred following the discovery that dysregulation of IL-1 signalling underlies the pathogenesis of several monogenic auto-inflammatory diseases, characterized by sterile inflammation involving the skin and other organs. This also provided increased understanding of the role of innate immunity and the IL-1 family in polygenic auto-inflammatory skin conditions, such as neutrophilic dermatoses, as well as in some of the most common chronic inflammatory skin diseases, such as psoriasis or hidradenitis suppurativa. Several therapeutic agents have been developed to inhibit the IL-1 family members and their signalling pathways. These have shown therapeutic efficacy in several chronic inflammatory skin disorders. The aim of this review is to thoroughly describe the consequences of pathological dysregulation of IL-1, IL-33, IL-36, IL-18 pathways in dermatological conditions and to provide a forward-looking update on therapeutic strategies targeting signalling by IL-1 family cytokines.

Principal Component Analysis to Differentiate Patients with Palmoplantar Pustulosis from Those with Palmoplantar Pustular Psoriasis

Background

Palmoplantar pustulosis (PPP) is initiated from the acrosyringium. However, it is unclear whether PPP should be considered a distinct entity or should be classified into the spectrum of pustular psoriasis, also known as palmoplantar pustular psoriasis (PPPP).

Objective

We evaluated the differences in immunohistochemical staining in patients with PPP to determine whether they can be classified into two groups based on psoriatic properties or acrosyringeal properties.

Methods

Nineteen punch biopsy specimens diagnosed with PPP were collected. Antibodies were chosen for identifying the acrosyringeal properties of α-3-nicotine acetylcholine receptors (α-3-nAChR), psoriatic properties of interleukin (IL)-23 and IL-36R, inflammatory cell properties of human cathelicidin antimicrobial peptide 18/LL-37, IL-8, lipocalin-2 (LCN2), and CD3. The degree of staining of the epidermis was evaluated using the ordinal scale (0~3). The principal component analysis was used to derive principal components (PCs) of common variation between the stains, and the two groups were divided using PCs and cluster analysis.

Results

Three main PCs explained 64% of the total variance in PPP. PC1 (pustular psoriasis properties) showed a higher correlation with IL-36R. PC2 (acrosyringeal/inflammatory properties) showed a higher correlation with α-3-nAChR, IL-8, LCN2, and CD3. PC3 (psoriasis properties) showed a higher correlation with IL-23. PC1 showed a statistically significant difference (p=0.0284) between the two groups. We identified three PCs associated with the pathomechanisms of PPP.

Conclusion

Although PC1 showed a statistically significant difference between the two groups, we did not identify differential protein expression related to the pathogenesis between PPP and PPPP.