Immediate response to apremilast in patients with palmoplantar pustulosis: a retrospective pilot study

308-nm excimer light is effective for palmoplantar pustulosis regardless of the presence or absence of focal infection: Single-center real-world experience of treatment for palmoplantar pustulosis

Palmoplantar pustulosis (PPP) is relatively rare and recognition of PPP is different in different countries. Therefore, real-world data are limited. Local phototherapy for the palms and the soles is commonly used to treat PPP due to tolerable safety. However, data on the effectiveness of 308-nm excimer light are limited. In our study, we retrospectively investigated the effectiveness of treatments for PPP, especially phototherapy (308-nm excimer light), in our department. In addition, we examined whether smoking status and focal infection affected responsiveness to treatment of PPP. Patients who were diagnosed with PPP by board-certified dermatologists and visited our hospital from April 2015 to August 2018 were analyzed in this study. We collected data on PPP area severity index (PPPASI) before treatment. We also collected data on PPPASI in May to August 2018 as "after treatment" from all patients. Patients who received any treatment for less than 3 months were excluded. Nineteen patients (16 women and three men) were analyzed in this study. In patients treated with phototherapy (n = 12), PPPASI significantly decreased from a mean ± SD of 16.5 ± 10.3 to 4.5 ± 3.6 (p = 0.004), whereas it did not in patients treated without phototherapy (n = 7). Patients who quit smoking showed a significant decrease in PPPASI after treatment (16.8 ± 12.7 to 2.4 ± 2.9, p = 0.008). Regarding focal infection, in patients treated without phototherapy, the reduction rate of PPPASI was significantly lower in patients with focal infection than in those without focal infection (17.7 ± 21.5%, 71.1 ± 19.3%, p = 0.035), indicating that focal infection is associated with intractability. Meanwhile, in patients treated with phototherapy, PPPASI decreased regardless of the presence or absence of focal infection. In conclusion, our study demonstrated the effectiveness of local phototherapy consisting of 308-nm excimer light, regardless of focal infection. Patients who quit smoking were responsive to any treatment, indicating the importance of smoking cessation.

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.

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.

Apremilast in Palmoplantar Psoriasis and Palmoplantar Pustulosis: A Systematic Review and Meta-analysis

BACKGROUND

This review's goals were to investigate apremilast's efficacy versus placebo in palmoplantar psoriasis (PP) and palmoplantar pustulosis (PPP), and apremilast's efficacy versus methotrexate in PP.

METHODS

A literature search was conducted in PubMed, clinicaltrials.gov, and Embase in July 2022. Publications investigating subjects with PP or PPP, treated with apremilast, which reported palmoplantar-specific outcomes were used. Exclusion criteria included cases of drug-induced PP/PPP, case studies, non-English texts, omission of palmoplantar-specific outcomes, and incomplete publications. Studies were assessed for risk of bias using Cochrane Review Manager application and CASP checklist. Primary endpoints were a 50% improvement of the Palmoplantar Psoriasis/Pustulosis Area and Severity Index (PPPASI 50) and improvement of the Palmoplantar Physician Global Assessment (PPPGA) to 0 or 1 in patients with baseline PPPGA ≥ 3.

RESULTS

Seventeen original studies including five placebo-controlled randomized clinical trials (RCTs), one phase II clinical trial, two randomized methotrexate comparative trials, six cohort studies, and three case series were analyzed, totaling 1117 participants. Meta-analysis of four placebo-controlled RCTs investigating PP found apremilast treatment to be superior to placebo in achieving a PPPGA of 0/1 (baseline PPPGA of ≥ 3) after 16 weeks of treatment (n = 244; OR = 2.69 [1.39-5.22]). Apremilast was superior to placebo in achieving PPPASI 50 at week 16 in the only placebo-controlled RCT of PPP (78.3 vs. 40.9%) [P = 0.0003]. Apremilast was comparable to methotrexate in achieving PPPASI 50 at week 16 in PP (59.5 vs. 64.3%; n = 84; [P = 0.65]). Non-randomized studies generally showed marked improvement in PPPASI, PPPGA, and DLQI scores following apremilast treatment.

DISCUSSION

Apremilast treatment in PP and PPP resulted in significant improvement in objective, palmoplantar-specific clinical parameters versus placebo, and comparable efficacy with methotrexate in PP. Limitations in interpreting these results include variations in palmoplantar-specific metrics used and risk of bias of included studies.

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.

Recent advances in palmoplantar pustulosis

Palmoplantar pustulosis (PPP) is a chronic inflammatory condition where crops of sterile pustules with erythematous keratotic lesions causing bleeding and pain appear on the palms and soles. Recently, the European Rare and Severe Expert Network considered PPP as a variant of pustular psoriasis with or without psoriasis vulgaris.

The prevalence of PPP varies from 0.050 to 0.12%. PPP occurs more frequently in women and the highest prevalence occurred between the ages of 50 and 69 years. Nail psoriasis seems to be frequent in PPP, ranging from 30 to 76%, and psoriatic arthritis in 8.6 to 26% of PPP patients.

Synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome and pustulotic arthro-osteitis are considered PPP-associated disorders. PPP has been reported with other co-morbidities such as psychiatric disorders, thyroid-associated disease, altered calcium homeostasis, gluten sensitivity diabetes, obesity, and dyslipidemia, but larger studies are required to prove such associations. Environmental exacerbating factors might contribute to the onset or worsening of PPP such as cigarette smoking, stress, focal infections, metal allergies, and drug intake. Genetic predisposition plays an important role in PPP.

In PPP, both the innate and the adaptive immune systems are activated. The acrosyringeal expression of IL-17 has been demonstrated, indicating that the eccrine sweat gland is an active component of the skin barrier and an immune-competent structure. Increased levels of several inflammatory molecules, including IL-8, IL-1α, IL-1β, IL-17A, IL-17C, IL-17D, IL-17F, IL-22, IL-23A, and IL-23 receptor, have been detected in PPP biopsies. Increased serum levels of TNF-α, IL-17, IL-22, and IFN-γ have been detected in patients with PPP in comparison to healthy subjects, suggesting a similar inflammatory pattern to psoriasis vulgaris. Oral and tonsillar infections serve as trigger factors for PPP.

Long-term therapy is required for many patients, but high-quality data are limited, contributing to uncertainty about the ideal approach to treatment.

Similarity and difference between palmoplantar pustulosis and pustular psoriasis

Palmoplantar pustulosis is a chronic inflammatory disorder characterized by sterile pustules predominantly involving the palms and soles. Palmoplantar pustulosis has many similar aspects to psoriasis, either plaque and pustular type, namely familial occurrence between palmoplantar pustulosis and psoriasis, the appearance of the Köbner phenomenon, joint involvement, and nail involvement. Pustular psoriasis is classified into generalized and localized types, and there are a number of papers regarding palmoplantar pustulosis as an acral variant of localized pustular psoriasis. Many Japanese dermatologists consider palmoplantar pustulosis to be a distinct entity from pustular psoriasis, and the coexistence of palmoplantar pustulosis and psoriasis is rare. However, outside Japan, palmoplantar pustulosis is often considered to be palmoplantar psoriasis or palmoplantar pustular psoriasis, and extra-palmoplantar lesions are also considered to be psoriasis. The purpose of the current review is to compare the similarities and differences between palmoplantar pustulosis and generalized/localized pustular psoriasis. Japanese patients with palmoplantar pustulosis have a close relationship with focal infection, and the associated bone-joint manifestation exclusively involves the anterior chest wall. Furthermore, pediatric occurrence of palmoplantar pustulosis is extremely rare, and difference of genetic background between palmoplantar pustulosis and psoriasis has also been reported. Treatment of focal infection often results in dramatic effects on both cutaneous lesions and joint pain of palmoplantar pustulosis. Those findings suggest that palmoplantar pustulosis should be separately considered from either palmoplantar psoriasis or palmoplantar pustular psoriasis. The clinicopathological features and therapeutic approach of both diseases are discussed.