The relationships of onset and exacerbation of pustulosis palmaris et plantaris to smoking and focal infections

Retrospective study of the clinical significance of the neutrophil-to-lymphocyte ratio in 79 patients with palmoplantar pustulosis

Palmoplantar pustulosis (PPP) is a chronic relapsing inflammatory skin disease characterized by multiple vesicles, pustules, and erythematous plaques on the palms and soles. The exacerbation of PPP is strongly associated with focal infections, such as tonsillitis, dental infections, and sinusitis, in Japan. Recently, the neutrophil-to-lymphocyte ratio (NLR) has been widely used as a convenient and useful marker for clinical conditions and various diseases; however, an association between PPP and NLR has not yet been established. We retrospectively analyzed 79 patients with PPP from our hospital to evaluate the clinical significance of the NLR. The average NLR value in patients with PPP was significantly higher than that in healthy controls (2.30 ± 1.02 vs 1.69 ± 0.45, P < 0.001). A comparative analysis of patients with PPP with and without infectious complications showed that there was a statistical difference in the NLR between patients with PPP with and without focal infections, whereas no significant difference was found for metal allergy, smoking, and pustulotic arthro-osteitis. Multivariate analysis indicated that the NLR was significantly associated with focal infections (odds ratio = 18.38, 95% confidence interval 3.86-87.35, P < 0.001). The NLR was also significantly correlated with C-reactive protein levels (P = 0.013, r = 0.2857). Interestingly, after symptom improvement, the NLR significantly decreased from the baseline levels. Furthermore, statistical analysis using the Youden's index revealed that an NLR of 2.28 or higher was associated with the risk of any focal infections in patients with PPP. These results suggest that the NLR has potential applications as a biomarker of the presence of focal infections in patients with PPP.

Efficacy and Safety of Brodalumab, an Anti-interleukin-17 Receptor A Monoclonal Antibody, for Palmoplantar Pustulosis: 16-Week Results of a Randomized Clinical Trial

BACKGROUND

Palmoplantar pustulosis (PPP), a refractory skin disease characterized by repeated eruptions of sterile pustules and vesicles on palms and/or soles, involves interleukin-17 pathway activation. Brodalumab, a fully human anti-interleukin-17 receptor A monoclonal antibody, is being investigated for use in PPP treatment.

OBJECTIVE

The aim was to assess the efficacy and safety of brodalumab in Japanese PPP patients with moderate or severe pustules/vesicles.

METHODS

A phase 3, randomized, double-blind, placebo-controlled trial was conducted between July 2019 and August 2022, at 41 centers in Japan. Patients aged 18-70 years with a diagnosis of PPP for ≥ 24 weeks, a PPP Area Severity Index (PPPASI) score of ≥ 12, a PPPASI subscore of pustules/vesicles of ≥ 2, and inadequate response to therapy were included. Participants were randomized 1:1 to receive brodalumab 210 mg or placebo, subcutaneously (SC) at baseline, weeks 1 and 2, and every 2 weeks (Q2W) thereafter until week 16. Changes from baseline to week 16 in the PPPASI total score (primary endpoint) and other secondary skin-related endpoints and safety endpoints were assessed.

RESULTS

Of the 126 randomized patients, 50 of 63 in the brodalumab group and 62 of 63 in the placebo group completed the 16-week period. Reasons for discontinuation were adverse event (n = 6), withdrawal by patient/parent/guardian (n = 3), progressive disease (n = 3), and lost to follow-up (n = 1) in the brodalumab group and Good Clinical Practice deviation (n = 1) in the placebo group. Change from baseline in the PPPASI total score at week 16 was significantly higher (p = 0.0049) with brodalumab (least-squares mean [95% confidence interval {CI}] 13.73 [10.91-16.56]) versus placebo (8.45 [5.76-11.13]; difference [95% CI] 5.29 [1.64-8.94]). At week 16, brodalumab showed a trend of rapid improvement versus placebo for PPPASI-50/75/90 response (≥ 50%/75%/90% improvement from baseline) and Physician's Global Assessment 0/1 score: 54% versus 24.2%, 36.0% versus 8.1%, 16.0% versus 0.0%, and 32.0% versus 9.7%, respectively. Infection was the dominant treatment-emergent adverse event (TEAE); the commonly reported TEAEs were otitis externa (25.4%/1.6%), folliculitis (15.9%/3.2%), nasopharyngitis (14.3%/4.8%), and eczema (14.3%/12.9%) in the brodalumab/placebo groups, respectively. The severity of most TEAEs reported was Grade 1 or 2 and less frequently Grade ≥ 3.

CONCLUSIONS

Brodalumab SC 210 mg Q2W demonstrated efficacy in Japanese PPP patients. The most common TEAEs were mild infectious events.

TRIAL REGISTRATION

NCT04061252 (Date of Trial Registration: August 19, 2019).

Optimal treatments and outcome measures of palmoplantar pustulosis: A systematic review and network meta-analysis-based comparison of treatment efficacy

Few studies have made direct comparisons between treatments for palmoplantar pustulosis (PPP); therefore, it is difficult to select the best treatment for each patient. To determine the best therapy and to compare reported measures of efficacy in clinical trials of systemic treatments for PPP in this systematic review and network meta-analysis. Six databases were used to perform database search on 10 July 2022. Randomized controlled trials (RCTs) were identified through a systematic literature search. The titles and abstracts of articles were initially screened for inclusion by two authors independently using our predetermined criteria. The full texts of selected articles were then independently assessed for inclusion in a blinded fashion. Disagreement between the authors was resolved by consensus. Data were abstracted in duplicate. Random-effects model was accepted to perform network meta-analysis. Assessed Grading of Recommendations Assessment, Development and Evaluation certainty of evidence were performed according to the PRISMA guidelines. The analysis was completed in July 2022. The primary outcome was the change of PPP Area and Severity Index (PPPASI) from baseline and the secondary outcome was the achievement of PPPASI-50 response. Seven RCTs with 567 patients were included. Guselkumab 100 mg was the one with the highest probability of reaching the proposed outcomes (mean difference [MD], -8.00; 95% confidence interval [CI], 4.88-11.11), while the achievement of PPPASI-50 response did not show a significant difference (odds ratio [OR], 3.79; 95% CI, 0.51-28.37). Guselkumab 200 mg was next to 100 mg of reaching the proposed outcomes (MD, -4.71; 95% CI, 2.12-7.30), while the achievement of PPPASI-50 response did not show a significant difference (OR, 2.34; 95% CI, 0.48-11.43). Network meta-analysis showed guselkumab 100 mg was the treatment with the highest probability of reaching both PPPASI and PPPASI-50 outcomes. Absolute PPPASI may be more appropriate as an outcome than PPPASI-50.

Utility of nailfold capillary assessment for predicting pustulotic arthro-osteitis in palmoplantar pustulosis based on a prospective cohort study

BACKGROUND

Pustulotic arthro-osteitis (PAO) is 1 of the most serious comorbidities associated with palmoplantar pustulosis (PPP). Risk factors of PAO development are not well-known.

OBJECTIVE

To evaluate the clinical significance of nailfold capillary (NFC) changes in patients with PPP.

METHODS

We conducted a prospective cohort study in a population of 102 PPP patients. Correlations of NFC abnormalities, including nailfold bleeding and enlarged capillaries, with the prevalence of PAO, the incidence of new PAO, and serum levels of cytokines were analyzed.

RESULTS

Detailed examination revealed that of 102 PPP patients, 52 without PAO and 50 with PAO. Both nailfold bleeding and enlarged capillaries were significantly more frequent in patients with PAO (50.0% vs 92.0%, P < .0001; 50.0% vs 94.0%, P < .0001). In addition, PPP patients without PAO were prospectively observed before they developed PAO (mean 28 months [1-52 months]). Multivariate analysis suggested that these NFC abnormalities were predictors of PAO development (hazard ratio 3.37, 95% confidence interval 1.13-10.07; 3.37, 1.13-10.07) and guselkumab prevent PAO development (0.093, 0.012-0.76). The degree of NFC abnormalities correlated with the severity of PAO and serum cytokine levels.

LIMITATIONS

All participants were Japanese.

CONCLUSION

NFC abnormalities could be predictors of PAO in PPP patients, and their degree indicators of disease severity.

Palmoplantar pustulosis and acrodermatitis continua of Hallopeau: demographical and clinical comparative study in a large multicentre cohort

Background

Acral pustular disease within the pustular psoriasis/psoriasis‐like spectrum mainly includes palmoplantar pustulosis (PPP) and acrodermatitis continua of Hallopeau (ACH). Scarce data argue for a distinction between these two entities, but no study has compared the clinical and epidemiologic characteristics of ACH and PPP.

Objectives

We aimed to perform a comparative description of the epidemiological and clinical characteristics of PPP and ACH in a multicentre retrospective cohort.

Methods

In this multicentre national retrospective cohort study, we compared the epidemiological characteristics, comorbidities and psoriasis characteristics of patients with PPP and ACH.

Results

A total of 234 patients were included: 203 (87%) with PPP, 18 (8%) with ACH and 13 (6%) with both, according to 2017 ERASPEN criteria. As compared with ACH, PPP was associated with female sex, smoking activity and higher median BMI (P = 0.01, P = 0.02 and P = 0.05 respectively). A family background of psoriasis was more frequent in PPP than ACH. Age of onset of palmoplantar disease was similar between PPP and ACH patients, median age 44 and 48 years respectively. Peripheral joint inflammatory involvement was the only rheumatic disease associated with ACH. The association with another psoriasis type was similar in PPP and ACH (57.6% and 61.1% respectively).

Conclusion

Our study confirms in a large PPP cohort the predominance of females and a high prevalence of smoking and elevated body mass index but also shows an association of these features in PPP as compared with ACH. In addition, it highlights peripheral arthritis as the only arthritis endotype associated with ACH. Increased knowledge of the immunogenetic backgrounds underlying these two entities is warranted to better stratify pustular psoriasis or psoriasis‐like entities for precision medicine.

Efficacy and safety of guselkumab and adalimumab for pustulotic arthro-osteitis and their impact on peripheral blood immunophenotypes

OBJECTIVES

We compared the treatment effectiveness between guselkumab and adalimumab in patients with pustulotic arthro-osteitis (PAO). In addition, we performed peripheral blood immunophenotyping to elucidate the immunological background and analyzed the impact of therapeutic drugs to verify the validity of immunological phenotypes as therapeutic targets.

METHODS

Patients were treated with guselkumab 100 mg (guselkumab group; n = 12) and adalimumab 40 mg (adalimumab group; n = 13). Arthritis disease activity, skin lesion activity, and patient-reported outcomes (PROs) were evaluated and compared between the two groups. The retention rate and adverse events were evaluated. Comprehensive phenotyping of peripheral immune cells was performed in both groups, and phenotypes were compared before and after treatment.

RESULTS

At 6 months, both groups showed significant improvement in arthritis disease activity and PROs. In the guselkumab group, skin symptoms significantly improved. The 6-month continuation rates were 91.7% (11/12) and 69.2% (9/13) in the guselkumab and adalimumab groups, respectively. Adverse events occurred in 2/12 and 5/13 patients in the guselkumab (16.7%) and adalimumab (38.5%) groups, respectively. Peripheral blood immunophenotyping showed that the proportion of activated T helper (Th) 1 cells was significantly lower in patients with PAO than in healthy controls and that the proportion of activated Th17 cells was significantly higher in patients with PAO, which significantly decreased after treatment with guselkumab.

CONCLUSION

Although guselkumab and adalimumab have comparable efficacy for PAO, their impact on immunophenotypes varies.

Pustular Psoriasis: From Pathophysiology to Treatment

Pustular psoriasis (PP) is a clinicopathological entity encompassing different variants, i.e., acute generalized PP (GPP), PP of pregnancy (impetigo herpetiformis), annular (and circinate) PP, infantile/juvenile PP, palmoplantar PP/palmoplantar pustulosis, and acrodermatitis continua of Hallopeau (ACH), which have in common an eruption of superficial sterile pustules on an erythematous base. Unlike psoriasis vulgaris, in which a key role is played by the adaptive immune system and interleukin (IL)-17/IL-23 axis, PP seems to be characterized by an intense inflammatory response resulting from innate immunity hyperactivation, with prominent involvement of the IL-36 axis. Some nosological aspects of PP are still controversial and debated. Moreover, owing to the rarity and heterogeneity of PP forms, data on prognosis and therapeutic management are limited. Recent progresses in the identification of genetic mutations and immunological mechanisms have promoted a better understanding of PP pathogenesis and might have important consequences on diagnostic refinement and treatment. In this narrative review, current findings in the pathogenesis, classification, clinical features, and therapeutic management of PP are briefly discussed.

Effects of tobacco and vaping on the skin

Cigarette and electronic cigarette use are significant public health concerns across the United States. Tobacco use remains the single most preventable cause of morbidity and mortality in the world. Electronic cigarettes initially emerged as a better alternative to conventional cigarettes and for promoting smoking cessation; however, current evidence reveals similar deleterious health implications caused by both products on almost all organ systems, including the skin. Recognition of the cutaneous manifestations associated with cigarette and electronic cigarette use is essential for dermatologists in current clinical practice. Dermatologists play a vital role in educating and counseling patients on smoking cessation. We specifically highlight the cutaneous consequences of conventional cigarette smoking and electronic cigarettes on dermatologic disease.

Pharmacokinetic/Pharmacodynamic Analysis of Guselkumab for Treatment of Palmoplantar Pustulosis: Clinical Implications of Guselkumab Dose, Disease Severity and Smoking in Japanese Patients

Guselkumab is a human IgG1λ monoclonal antibody that has been approved for treatment of multiple immunological diseases including palmoplantar pustulosis (PPP) in Japan. The efficacy of guselkumab in reducing disease severity as compared with placebo has been demonstrated in phase 2 and 3 clinical studies. In some patients assigned to the placebo treatment, worsening of PPP Area and Severity Index (PPPASI) score was noted. Most of these patients were smokers, raising a possibility of an association of smoking with the disease progression. To understand the clinical implications of guselkumab dose, baseline disease severity and smoking on the treatment effect and describe the longitudinal relationship between guselkumab exposure and the PPPASI score, a PK/PD modeling analysis was conducted using the pooled data from one phase 2 and one phase 3 study. Data from 207 Japanese patients (77% women and 60% smokers) with a median PPPASI score of 24.6 were included in the analysis. The observed treatment efficacy (the PPPASI score reduction) appeared to be similar at the current approved dose (100) mg and the higher dose (200 mg). Greater extent of the PPPASI score reduction (in absolute points) is expected in patients with higher baseline PPPASI score (severe disease). However, the higher baseline did not translate to larger magnitude of the change from baseline (in percentage) in the PPPASI score. Incorporating a linear disease progression effect in the model significantly decreased the NONMEM objective function value (p<0.001). Smoking status appeared tobe related to disease worsening in some patients, but the covariate did not reach statistical significance in the model. This article is protected by copyright. All rights reserved.

Clinical characteristics and treatment status of pustulotic arthro-osteitis: A single-center study involving 51 cases

Pustulotic arthro-osteitis (PAO) is a major complication of palmoplantar pustulosis (PPP). In orthopedic surgery outpatient clinics, PPP patients with osteoarticular symptoms are seen frequently, but PAO's clinical features remain not well known. To determine Japanese patients' clinical features and treatment status with PAO, we conducted a single-center retrospective epidemiologic survey. Clinical features, including gender, age, smoking habit, the onset pattern, interval between skin manifestation and osteoarticular symptoms, and the incidence of sternoclavicular joint lesions, axial and peripheral joint lesions, were examined. The association between physical status and image findings by X-ray, computed tomography, bone scintigraphy with Technetium⁹⁹ , or magnetic resonance imaging was evaluated. The distribution pattern of peripheral joint lesions and the treatment status were evaluated. We identified 51 patients, 10 men and 41 women, with PAO. The average age was 48 years and 59% were smokers. The frequency of onset patterns was skin-leading type (63%), simultaneous onset (18%), and osteoarticular leading type (16%). The average interval between skin involvement and osteoarticular involvement in skin-leading type was significantly longer than that in osteoarticular leading type (7.1 years vs. 2.0 years). A sternoclavicular joint (SCJ) lesion was detected in 65% cases, and the physical findings of SCJ were significantly related to the image findings. Axial and peripheral joint lesions were detected in the same ratio (23 cases, 45%). In the peripheral joints, the finger joint was the most common (26%), followed by the shoulder joint (21%). Patients were treated with nonsteroidal anti-inflammatory drugs (76%), followed by conventional synthetic disease-modifying antirheumatic drugs (DMARDs) (29%) and biological DMARDs (9.8%). Tonsillectomy was performed in 11 cases. In conclusion, PAO more frequently involves SCJ in middle-aged women who smoke. Given that osteoarticular leading type was detected in 16% cases, seronegative oligoarthritis patients should be monitored for PPP, leading to a diagnosis of PAO.

Cigarette Smoke Underlies the Pathogenesis of Palmoplantar Pustulosis via an IL-17A-Induced Production of IL-36γ in Tonsillar Epithelial Cells

Palmoplantar pustulosis (PPP) is characterized by sterile pustules on the palms and soles. A strong association between PPP and tobacco smoking has been reported, and it has been speculated that the IL-17A pathway may play an important role in PPP. Recent studies have suggested that IL-36 plays a pivotal role in the pathogenesis of psoriasis and its subtypes. The relationships among IL-36, smoking, and PPP have not been examined. Here, we investigated the relationships among the smoking index, severity of the clinical condition of PPP, and in vitro dynamics of IL-36 in human tonsillar epithelial cells under the condition of exposure to a cigarette smoke extract. The results demonstrated that the Palmoplantar Pustulosis Area and Severity Index was strongly and positively correlated with the smoking index in female patients. Immunohistochemical examinations showed that IL-36γ was highly expressed in tonsillar epithelial cells from patients with PPP but not in those from patients with recurrent tonsillitis without PPP. The in vitro study revealed that IL-17A synergistically induced a release of IL-36γ under cigarette smoke extract exposure. These results suggest that local production of IL-36γ by epithelial cells induced by cigarette smoke exposure plays an important role in the pathogenesis of PPP.

Chronic Nonbacterial Osteomyelitis of the Sternocostoclavicular Region in Adults: A Single-Center Dutch Cohort Study

Sternocostoclavicular hyperostosis (SCCH) is a rare autoinflammatory bone disorder caused by chronic nonbacterial osteomyelitis (CNO), which is associated with sclerosis and hyperostosis primarily affecting the sternum, the medial end of the clavicles, and the first ribs. Other areas of the axial skeleton may also be affected. The more severe synovitis–acne–pustulosis–hyperostosis–osteitis (SAPHO) syndrome is additionally associated with dermatoses and joint manifestations. This Dutch retrospective cross‐sectional single‐center cohort study characterizes the spectrum of clinical features in adult CNO/SCCH patients at the time of diagnosis. The only inclusion criteria was the availability of complete sets of clinical and imaging data systematically collected over three decades using in‐house protocols. Data from 213 predominantly female patients (88%) with a median age of 36 years at presentation were studied. The mean diagnostic delay was 5 ± 5 years. The main symptoms were chronic pain (92%), bony swelling (61%), and restricted shoulder girdle function (46%); 32% had palmoplantar pustulosis and 22% had autoimmune disease. The majority (73%) had isolated SCCH; 59 (27%) had additional localizations in vertebrae (19%), the mandible (9%), or both (2%); 4 had SAPHO. The prevalence of current or past smoking was high (58%), particularly for patients with palmoplantar pustulosis (76%). There was a significant relationship between delay in diagnosis and both the extent of affected skeletal sites (p = 0.036) and erythrocyte sedimentation rate levels (p = 0.023). Adult‐onset CNO is characterized by distinctive clinical and radiological features, but diverse aspects of its spectrum are currently not fully captured by a comprehensive classification. Delayed diagnosis is still common and potentially associated with irreversible structural changes and debilitating chronic symptoms, increasing the burden of illness and negatively impacting on quality of life. It is hoped that findings from this study will dispel confusion about nomenclature and classification of adult‐onset CNO and increase awareness of its distinctive clinical and radiological features, and thus facilitate early diagnosis and referral for treatment, which should positively impact prognosis by preventing disease progression, although this remains to be established. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

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.

Dysbiosis of Oral Microbiota Associated with Palmoplantar Pustulosis

BACKGROUND

Dysbiosis of oral microbiota is implicated not only in oral inflammatory lesions, but also in a variety of extraoral diseases. The etiology of palmoplantar pustulosis (PPP) remains unclear; however, it has been suggested that chronic inflammation caused by periodontopathic bacterial infection may play a role.

OBJECTIVES/METHODS

To determine whether patients with PPP have altered diversity and composition of oral microbiota, we conducted the 16S rDNA analysis using saliva samples collected from 21 outpatients with PPP and 10 healthy individuals.

RESULTS

We found that the proportion of bacteria in the phylum Proteobacteria was significantly lower in PPP patients (p = 0.025). At the genus level, patients with PPP had a significantly lower abundance of Neisseria (p = 0.014), which best accounted for the observed decrease in Proteobacteria. We also identified multiple minor genera and species that were represented at a significantly higher level in the PPP group, several of which have been associated with periodontal diseases.

CONCLUSION

Our results suggest a possible link between PPP and dysbiosis of oral microbiota, particularly the lower abundance of Neisseria, the most predominant genus of Proteobacteria in healthy oral microbiota. Probiotics that improves oral dysbiosis may be beneficial for patients with PPP as an adjunctive therapy.

Impact of smoking on psoriasis risk and treatment efficacy: a meta-analysis

Objective

Psoriasis is an immune-mediated chronic inflammatory disease with skin and joint manifestations. Smoking is considered an unfavorable lifestyle factor for psoriasis. We aimed to explore the association between smoking, disease risk, and treatment efficacy in relation to psoriasis.

Methods

We searched the Cochrane Library, Embase, and PubMed databases for studies examining the relationship between smoking and psoriasis, up to 12 April 2020. We then conducted a meta-analysis using a fixed-effects model to obtain odds ratios (ORs) with 95% confidence intervals (CIs).

Results

Ever, current, and former smokers all had higher risks of developing psoriasis than non-smokers (pooled ORs (95% CIs): 1.60 (1.51–1.69), 1.63 (1.48–1.80), and 1.36 (1.13–1.64), respectively). Ever smokers were less likely to show disease improvement at 6 months following treatment with biologic agents than non-smokers (pooled OR (95% CI): 0.80 (0.67–0.95)).

Conclusions

Smoking increases psoriasis risk and negatively impacts the benefits of biologic agents. However, the number of reports is limited and more studies are needed to confirm the effects of smoking and smoking cessation on therapeutic response in patients with psoriasis. Education to encourage a healthy lifestyle remains a valuable approach in clinical practice.

Diagnosis, Screening and Treatment of Patients with Palmoplantar Pustulosis (PPP): A Review of Current Practices and Recommendations

Palmoplantar pustulosis (PPP) is a rare, chronic, recurrent inflammatory disease that affects the palms and/or the soles with sterile, erupting pustules, which are debilitating and usually resistant to treatment. It has genetic, histopathologic and clinical features that are not present in psoriasis; thus, it can be classified as a variant of psoriasis or as a separate entity. Smoking and upper respiratory infections have been suggested as main triggers of PPP. PPP is a challenging disease to manage, and the treatment approach involves both topical and systemic therapies, as well as phototherapy and targeted molecules. No gold standard therapy has yet been identified, and none of the treatments are curative. In patients with mild disease, control may be achieved with on-demand occlusion of topical agents. In patients with moderate-to-severe PPP, phototherapy or a classical systemic agent (acitretin being the best treatment option, especially in combination with PUVA) may be effective. Refractory patients or those with contraindications to use these therapies may be good candidates for apremilast or biologic therapy, particularly anti-IL-17A and anti-IL-23 agents. Recent PPP trials are focusing on blockage of IL-36 or IL-1 pathways, which play an important role in innate immunity. Indeed, IL-36 isoforms have been strongly implicated in the pathogenesis of psoriasis. Therefore, blockage of the IL-36 pathway has become a new treatment target in PPP, and three studies are currently evaluating the use of monoclonal antibodies that block the IL-36 receptor in PPP: ANB019 and spesolimab (BI 655130). In this review, we explore the diagnosis, screening and treatment of patients with PPP.

Treatment patterns and healthcare resource utilization in palmoplantar pustulosis patients in Japan: A claims database study

Background

Palmoplantar pustulosis (PPP) is a chronic, relapsing, inflammatory autoimmune condition, characterized by sterile pustules on the palms and soles. The treatment patterns of PPP and total health care resource utilization in Japan are not well described. Investigating these areas is needed to understand current PPP management in Japan.

Objective

To describe the characteristics, medication treatment and health care resource utilization patterns, and associated costs of PPP patients in Japan.

Methods

A retrospective analysis of insurance claims data was conducted using the Japan Medical Data Center database. Adult Patients with at least two claims with a PPP diagnosis from January 1, 2011 to March 30, 2017 and six months of follow-up after the first diagnosis were included. Patient characteristics described include age, gender, and comorbid conditions. Treatment patterns assessed include the types of treatment, sequence of treatment, and rates of discontinuation, switching, persistence and use of concomitant medications.

Results

A total of 5,162 adult patients met all inclusion criteria. Mean (SD) patient age was 49.7 (11.6) years and 43.2% were male. A total of 2441 patients (47.8%) received systemic non-biologic drugs during the entire follow up period, 2,366 (46.4%) were prescribed topical therapy, 273 (5.4%) were prescribed phototherapy, while 18 (0.4%) of patients with other autoimmune comorbidities were eligible for prescribed biologics. For treatment-naïve patients with mild PPP, topical therapy was most commonly (77.1%) prescribed, whereas in moderate to severe cases of PPP, systemic non-biologic drugs (65%) were most often used. The frequency of switching was similar (64.3% to 75.3%) across various therapies and treatment lines.

Conclusion

This study describes the treatment patterns and health care resource utilization for Japanese PPP patients using a large claims database, and highlights an unmet need to derive better treatment strategies for PPP and address disease burden in Japan.

Characteristics of Japanese patients with pustulotic arthro-osteitis associated with palmoplantar pustulosis: a multicenter study

BACKGROUND

Pustulotic arthro-osteitis (PAO) is a major comorbidity of palmoplantar pustulosis (PPP), which is frequently seen in Japanese patients. To determine the characteristics of Japanese patients with PAO, we conducted a multicenter, retrospective epidemiologic survey at four university hospitals.

METHODS

Clinical features including age, gender, duration of disease, extrapalmoplantar lesion, smoking habit, focal infection, site of joint pain, bone scintigraphy with Technetium⁹⁹ , and therapies were retrospectively evaluated.

RESULTS

In total, 165 patients with PAO were identified among 576 patients with PPP (28.6%). The male to female ratio was 1 : 3.7, and the mean age was 50.2 years. The mean disease duration of PAO was 6.0 years. Smoking habit was observed in 104 patients. Focal infection was detected in 74 patients, who developed tonsillar infection (n = 41), sinusitis (8), odontogenic infection (40), and others (2). Fifteen patients had multifocal infection. Technetium bone scintigraphy was performed in 97 cases. Increased uptake was most frequently observed in the sternocostoclavicular regions, followed by wrist and ankle, sacroiliac joint, knee and elbow, finger and toe, lumbar spine, thoracic spine, scapula, and thigh. Patients were mainly treated with nonsteroidal anti-inflammatory drugs, methotrexate, cyclosporine, antibiotics, and biologics, as well as tonsillectomy and dental treatment.

CONCLUSION

PAO frequently involves the anterior chest wall of middle-aged women with smoking habit and is closely associated with focal infection.

The microbiome of the "sterile" pustules in palmoplantar pustulosis

The skin microbiome influences skin pathophysiology. Palmoplantar pustulosis (PPP) is a chronic skin disease characterized by infectious-like pustules on the palms and soles. These pustules are thought to be sterile because bacterial cultures obtained from the pustules are negative. However, culture methods are limited in their ability to identify all bacteria on the skin. We hypothesized that the "sterile" pustules of PPP do not lack bacteria, but rather contain a microbiome. To test this hypothesis, we identified bacteria in "sterile" pustules using non-culture methods. We conducted Sanger and 16S rRNA sequencing using primers specific to the V1-V2 region in PPP-pustulovesicles (PVs) (n = 43) and pompholyx vesicle fluids (n = 15). Sanger sequencing identified some Staphylococcus, Propionibacterium, Streptococcus and Pyrinomonas species in PPP-PVs but failed to identify any bacteria in most of the pompholyx vesicles. 16S rRNA sequencing of PPP-PVs indicated the presence of a microbiome that included various phyla, including Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. At the genus level, smokers had higher levels of Staphylococcus in PPP-PVs compared with non-smokers. These results indicate that a microbiome exists in "sterile" pustules of PPP and that PPP smokers had higher levels of Staphylococcus in pustules. It is therefore necessary to reconsider the pathogenesis of PPP from the perspective of the microbiome.

Efficacy and Safety of Guselkumab, an Anti-interleukin 23 Monoclonal Antibody, for Palmoplantar Pustulosis: A Randomized Clinical Trial

Importance

Palmoplantar pustulosis (PPP) is a recalcitrant skin disease with no biologics currently approved for treatment. The involvement of interleukin 23 (IL-23) and cytokines of the type 17 helper T cell lineage in the pathogenesis of PPP has been recently postulated.

Objective

To evaluate the efficacy and safety of guselkumab, an anti-IL-23 monoclonal antibody, in Japanese patients with PPP.

Design, Setting, and Participants

This double-blind, randomized, placebo-controlled, parallel-group, 24-week trial was conducted between May 14, 2013, and September 27, 2014, at 11 centers in Japan. Participants were patients with moderate to severe PPP that did not respond adequately to conventional treatments.

Interventions

Patients were randomized 1:1 to receive guselkumab, 200 mg, by subcutaneous injection or matching placebo at weeks 0 and 4.

Main Outcomes and Measures

Changes in total scores of skin-related outcomes from baseline at the end of week 16 (primary clinical cutoff) and through week 24 were measured. Serum biomarker analyses were performed at baseline, week 4, and week 16, and safety was monitored through week 24.

Results

Of 49 randomized patients (35 [71%] women; median [range] age, 52 [28-77] years), 41 completed the study at week 24. Mean (SD) PPP severity index total scores (primary end point) improved significantly from baseline in guselkumab-treated patients (-3.3 [2.43]) vs placebo (-1.8 [2.09]) (least squares mean difference, -1.5; 95% CI, -2.9 to -0.2; P = .03). At week 16, PPP area and severity index scores (least squares mean difference, -5.65; 95% CI, -9.80 to -1.50; P = .009) and proportion of patients achieving 50% reduction in these scores (difference in proportion, 39.2; 95% CI, 14.0-64.3; P = .009) improved significantly. A numerically higher proportion of patients had a physician's global assessment score of 1 or less in the guselkumab group vs placebo. Improvement in efficacy scores was maintained through week 24 in the guselkumab group. Significant reductions from baseline in serum IL-17A and IL-17F cytokine levels were observed at weeks 4 and 16. Frequency of treatment-emergent adverse events was comparable between the guselkumab group (19 of 25 patients [76%]) and the placebo group (18 of 24 patients [75%]). Frequent adverse effects included nasopharyngitis (14 patients [29%]), headache (3 patients [6%]), contact dermatitis (3 patients [6%]), and injection site erythema (3 patients [6%]). No major safety concerns emerged during the study.

Conclusions and Relevance

Targeting IL-23 and its associated immune cascade with guselkumab may be a safe and useful therapeutic option for treatment of PPP.

Trial Registration

clinicaltrials.gov Identifier: NCT01845987.

Clinical features and radiological findings of 67 patients with SAPHO syndrome

OBJECTIVES

The purpose of this study was to facilitate the understanding of the SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis) syndrome by analyzing the clinical and radiological features of 67 Japanese patients with SAPHO syndrome.

METHODS

Sixty-seven Japanese patients (female/male: 44/23, mean age at onset: 48.5 years) were diagnosed with SAPHO syndrome from 2002 to 2013 at our hospital. Medical records and radiological imaging of these patients were retrospectively reviewed.

RESULTS

Among the 67 patients, 41 had dermatological manifestations, such as palmoplantar pustulosis, acne, and psoriasis. Initial symptom was local pain in all patients, and the most common initial site of the symptom was the anterior chest. Bacterial and fungal cultures from 20 bone biopsies were all negative. Histopathological diagnosis of the specimens was non-specific inflammation in all cases. Bone lesions were observed in 65 patients (97.0%). On the other hand, articular lesions including enthesitis were found in 31 patients (46.2%).

CONCLUSION

SAPHO syndrome had different clinical and radiological aspects. The clinical features were not remarkable, except the dermatological manifestations and the involvement of the anterior chest. Bone lesions including hyperostosis and osteitis were found radiographically in the majority of patients with SAPHO syndrome. These are the characteristics of the SAPHO syndrome, with the exclusion of other bone diseases.

Clinical Features, Etiologic Factors, Associated Disorders, and Treatment of Palmoplantar Pustulosis: The Mayo Clinic Experience, 1996-2013

OBJECTIVE

To further characterize clinical characteristics, etiologic factors, associated disorders, and treatment of palmoplantar pustulosis (PPP).

PATIENTS AND METHODS

We conducted a retrospective review of patients with PPP at Mayo Clinic between January 1, 1996, and December 31, 2013.

RESULTS

Of 215 patients with PPP identified, 179 (83%) were female, and the mean age at onset was 45.3 years. Most patients (n=165, 77%) were current or former smokers. At diagnosis, 15 patients (7%) had an anxiety diagnosis and 9 (4%) had an infection. Nineteen cases (9%) were drug induced. Comorbid conditions included thyroid disease in 18 patients (8%), gluten sensitivity in 3 (1%), and type 2 diabetes mellitus in 21 (10%). In all, 194 patients (90%) received topical corticosteroids, 55 (26%) received phototherapy, and 54 (25%) received systemic agents.

CONCLUSION

More than three-fourths of the patients in this study had a history of smoking, which is considered a triggering or aggravating factor for PPP. Regarding comorbid conditions, gluten sensitivity and thyroid disease were found less frequently than previously reported in the literature. Treatment regimens and responses in this cohort varied considerably.

Insulin resistance, diabetes mellitus and thyroid dysfunction in patients with palmoplantar pustulosis: a case-controlled study

Introduction

Palmoplantar pustulosis (PPP) is a chronic pustular inflammatory skin disease; however, its pathogenesis is not well understood. Several factors, such as genetics, tobacco use and autoimmune issues, may contribute to this disease.

Aim

This research was conducted to investigate the relationships between insulin resistance, thyroid disease and PPP.

Material and methods

Thirty-three patients with PPP and 27 age- and gender-matched controls were analysed for their smoking histories, thyroid function tests, anti-thyroid peroxidase antibody (anti-TPO) levels, fasting glucose, fasting insulin levels and the homeostatic model assessment (HOMA) index for insulin resistance.

Results

We found significant differences between the PPP and control groups according to their tobacco use and anti-TPO levels (p = 0.009 and p = 0.009, respectively). The proportion of tobacco use was 90% in the PPP patients and 63% in the controls. Gender and tobacco use were predictive risk factors for PPP in the multivariate analysis (OR = 141.7, p < 0.0001 and OR = 147.6, p = 0.006, respectively). An anti-TPO level > 35 U/ml and the presence of a thyroid abnormality were independent risk factors in the univariate, but not the multivariate analysis (OR = 4.2, p = 0.025 and OR = 5.4, p = 0.004, respectively). A moderate correlation between the gender and anti-TPO level was found (r = 0.361, p = 0.039); however, the fasting glucose, insulin and HOMA index were not significant between the PPP and control groups.

Conclusions

Female gender and smoking were the most important risk factors for PPP; however, the increase in the anti-TPO level may be related to the predominance of females afflicted with this disease. Additional studies are necessary to clarify the relationships between PPP, thyroid disease and diabetes mellitus.

Pustular psoriasis: pathophysiology and current treatment perspectives

Psoriasis vulgaris is a chronic inflammatory disease that classically affects skin and joints and is associated with numerous comorbidities. There are several clinical subtypes of psoriasis including the uncommon pustular variants, which are subdivided into generalized and localized forms. Generalized forms of pustular psoriasis include acute generalized pustular psoriasis, pustular psoriasis of pregnancy, and infantile and juvenile pustular psoriasis. Localized forms include acrodermatitis continua of Hallopeau and palmoplantar pustular psoriasis. These subtypes vary in their presentations, but all have similar histopathologic characteristics. The immunopathogenesis of each entity remains to be fully elucidated and some debate exists as to whether these inflammatory pustular dermatoses should be classified as entities distinct from psoriasis vulgaris. Due to the rarity of these conditions and the questionable link to the common, plaque-type psoriasis, numerous therapies have shown variable results and most entities remain difficult to treat. With increasing knowledge of the pathogenesis of these variants of pustular psoriasis, the development and use of biologic and other immunomodulatory therapies holds promise for the future of successfully treating pustular variants of psoriasis.

What do we know about palmoplantar pustulosis?

Palmoplantar pustulosis is characterized by a chronic eruption of sterile pustules on palms and soles. The disease affects mainly women in the sixth and seventh decade of life. Some authors consider palmoplantar pustulosis a separate entity, whereas others consider it a condition in the spectrum of psoriasis. Aim of this study was to summarize the most recent data about PPP which aimed at establishing the nosological position of palmoplantar pustulosis. A systematic search of published literature was carried out. General characteristics of patients with PPP in different populations were present. We reviewed histological, immunological and genetic studies, as well as treatment options for PPP. PPP presents with clinical features, which are not present in psoriasis; however, the common coexistence of psoriasis vulgaris and/or positive family history for psoriasis indicates at least a close relationship between PPP and psoriasis. At present, there are not sufficient data to exclude PPP from psoriasis group.

Cefcapene Pivoxil Hydrochloride Is a Potentially New Treatment for Palmoplantar Pustulosis with Pustulotic Arthro-Osteitis

Pustulosis palmaris et plantaris or palmoplantar pustulosis (PPP) is a refractory pustular eruption of the palms and soles with unknown etiology. In addition to skin lesions, PPP patients may present with severe joint pain and pustulotic arthro-osteitis (PAO), especially of the sternoclavicular joint. PAO is sometimes regarded as a variant of synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome. Hence, macrolide and tetracycline antibiotics are used for the treatment of PPP with PAO. We report 3 cases of PPP with PAO that did not improve upon administration of macrolide antibiotics with NSAIDs. After administration of cefcapene pivoxil hydrochloride (CFPN-PI), a third-generation cephalosporin, the swelling and sternoclavicular joint pain were promptly reduced and dramatically improved in all 3 cases. We review the conventional antibiotic treatments used currently and propose CFPN-PI as a potentially new therapy for PPP or PPP + PAO.

The spontaneous regression of palmoplantar pustulosis following removal of dental amalgams: A report of two cases

Metal allergens are occasionally reported to be associated with palmoplantar pustulosis. We describe two severe, therapy-resistant, chronic cases of palmoplantar pustulosis induced by metal dental fillings. Both patients' clinical findings and symptoms regressed following the removal of their metal teeth. A patch test examination revealed positive reactions to metal allergens in both cases (in Case 1 the positive reactions were to cobalt chloride hexahydrate and nickel sulfate and in Case 2 the positive reaction was to nickel sulphate). Our studies suggest that metal allergens may play an important role in the pathogenesis of palmoplantar pustulosis.

Role of AhR/ARNT system in skin homeostasis

Aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that binds to structurally diverse synthetic and naturally occurring chemicals including dioxins, flavonoids, tryptophan photoproducts, and Malassezia metabolites. Upon binding to its ligands, cytoplasmic AhR translocates to the nucleus, heterodimerizes with aryl hydrocarbon receptor nuclear translocator (ARNT), and mediates numerous biological and toxicological effects by inducing the transcription of various AhR-responsive genes. AhR ligation controls oxidation/antioxidation, epidermal barrier function, photo-induced response, melanogenesis, and innate immunity. This review summarizes recent advances in the understanding of the regulatory mechanisms of skin homeostasis mediated by the AhR/ARNT system.

Pustulotic arthro-osteitis associated with palmoplantar pustulosis

Palmoplantar pustulosis (PPP) is a chronic inflammatory disorder characterized by sterile pustules predominantly involving the palms and soles of middle-aged women. PPP frequently develops or exacerbates following focal infections, such as tonsillitis, odontogenic infection and sinusitis, either with or without arthralgia and/or extra-palmoplantar lesions. Pustulotic arthro-osteitis (PAO) is a joint comorbidity of PPP, most often affecting the anterior chest wall. PAO is sometimes regarded as the same entity as synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome, and may be a subtype or incomplete type of SAPHO syndrome; however, there are several differences. In Japanese patients, PPP with PAO is frequently seen, whereas SAPHO syndrome in the true meaning is rare. A difference of incidence depending on race suggests that different genetic backgrounds may be responsible for susceptibility to these disorders. Bacterial infection, especially Propionibacterium acnes, is suggested to play an important role in the pathogenesis of SAPHO syndrome. P. acnes is responsible for acne, however, bacterium is unassociated with PPP skin lesions which are characterized by sterile pustules. On the other hand, PAO is frequently triggered by focal infection, and treatment of focal infection results in dramatic effects on the release of joint pain. This paper reviews current insights into the clinicopathophysiology of PAO, and discusses its possible mechanisms in comparison with SAPHO syndrome.

Autoinflammatory pustular neutrophilic diseases

This article provides a new categorization of inflammatory pustular dermatoses in the context of recent genetic and biological insights. Monogenic diseases with pustular phenotypes are discussed, including deficiency of interleukin 1 receptor antagonist, deficiency of the interleukin 36 receptor antagonist, CARD14-associated pustular psoriasis, and pyogenic arthritis, pyoderma gangrenosum, and acne. How these new genetic advancements may inform how previously described pustular diseases are viewed, including pustular psoriasis and its clinical variants, with a focus on historical classification by clinical phenotype, is also discussed.

Smoking and the skin

Cigarette smoking has been associated with significant morbidity affecting all systems of the body, including the integumentary system. We review the many dermatologic hazards of tobacco use. It is important to distinguish between the effects of tobacco smoke from effects of pure nicotine on the skin. All skin cells express several subtypes of the nicotinic class of acetylcholine receptors, including the α7 receptor. Many chronic dermatoses are affected by smoking either negatively or positively. Elucidation of positive associations with a particular disease can lead to improvement from smoking cessation, whereas inverse correlation may lead to development of a disease-specific treatment with nicotinergic agonists.

Cutaneous small vessel vasculitis accompanied by pustulosis palmaris et plantaris

We present the case of a 64-year-old woman who has suffered from pustulosis palmaris et plantaris for 10 years. At the first examination, many erythematous lesions with purpura, blood crusts, and blisters were present in the lower legs and dorsum of the feet. Painful swelling in the sternal region and dorsal pain were also noted. Elevation of the CRP and myogenic enzyme levels, and liver and renal dysfunctions were noted on blood testing. Histopathologically, leukocytoclastic vasculitis was noted in small blood vessels in the whole dermal layers, and deposition of IgM and C3 in the vascular wall was detected by the direct immunofluorescence techniques. Based on these findings, cutaneous small vessel vasculitis was diagnosed. Because the patient complained of a toothache during the clinical course, an X-ray examination was performed. On pantomography, a radicular cyst and apical periodontitis were noted. The tooth symptoms changed with exacerbation and remission of the skin symptoms. These findings indicate that odontogenic infection is very likely to be a cause of cutaneous small vessel vasculitis in a manner similar to pustulosis palmaris et plantaris.

Dermatoses neutrofílicas: parte II

Neste artigo são abordadas as dermatoses neutrofílicas, complementando o artigo anterior (parte I). São apresentadas e comentadas as seguintes dermatoses: pustulose subcórnea de Sneddon-Wilkinson, dermatite crural pustulosa e atrófica, pustulose exantemática generalizada aguda, acroder matite contínua de Hallopeau, pustulose palmoplantar, acropustulose infantil, bacteride pustular de Andrews e foliculite pustulosa eosinofílica. Uma breve revisão das dermatoses neutrofílicas em pacientes pediátricos também é realizada.

Association between palmoplantar pustulosis and cigarette smoking in Brazil: a case-control study

BACKGROUND

Palmoplantar pustulosis (PPP) discloses some differences compared to vulgar psoriasis (PV) in terms of age of onset, female predominance and low occurrence of psoriasis lesions elsewhere. Cigarette smoking has been associated to PPP in international studies; nevertheless, these studies were never performed among Brazilian.

OBJECTIVES

To compare prevalence of smoking among PPP, PV and other dermatologic patients (NPD).

METHODS

Case-control study involving 25 PPP patients from a reference psoriasis centre. Two control groups were matched according to gender and age: 50 patients with PV and 50 NPD. Confounders were adjusted by conditional multiple logistic regression.

RESULTS

Among cases, 84.0% were female and PPP age of disease onset (41.4 years) was greater than PV (34.5 years). Prevalence of ever smoking was higher among cases (92.0%) than PV (52.0%) and NPD (30.0%). Adjusted odds ratio of PPP ever smoking compared to PV and NPD was 9.5 and 36.2, respectively. All smokers reported the onset of their habit before the development of PPP.

CONCLUSIONS

There was significant association between PPP and smoking. However, the impact of giving it up in the clinical course of the disease remains to be established.

Neutrophilic dermatoses

Neutrophils may infiltrate all layers of the skin and consequently may cause different disorders, each with its own characteristic clinical and laboratory findings. We discuss how these disorders present and how they are diagnosed and treated. In addition, important associations with internal diseases are discussed to assist clinicians in evaluating for a concurrent illness. Because treatment of these disorders may often require systemic therapy, the potential short-term and long-term effects of commonly used medications are discussed. Finally, treatment of recalcitrant diseases, mostly by use of therapies published in the form of small case series or reports, is also included to guide clinicians in dealing with the more challenging cases.

Palmoplantar pustulosis: a clinicoepidemiological study. The relationship between tobacco use and thyroid function

BACKGROUND

Palmoplantar pustulosis (PPP) is a skin disease characterized by chronically recurring sterile pustules on the palms and the soles. Although the aetiology of PPP is unknown, it is interesting to note the high prevalence of tobacco use in these patients. It would seem that there may be a relationship between PPP, autoimmune diseases and alterations of thyroid function.

METHODS

We studied a total of 17 patients with ages ranging from 28 to 67 years, diagnosed with PPP. Patients were interviewed about: autoimmune diseases, psoriasis and thyroid disease, tobacco use (classified as: A, non-smoker; B, ex smoker; C, smoker of less than 20 cigarettes/day; D, smoker of more than 20 cigarettes/day). The patients were interviewed regarding the possible existence of a personal or family history of thyroid disease, determined using thyroid-stimulating hormone, thyroxine, antithyroid antibodies (antimicrosomal and antithyroglobulin antibodies).

RESULTS

The majority of the patients smoked cigarettes (according to classification). Of the 12 patients for whom a thyroid study was performed three had been diagnosed with thyroid diseases, an increase in thyroid-stimulating hormone in one case and two showed an increase in antimicrosomial antibodies.

CONCLUSIONS

We have been able to demonstrate a high prevalence of thyroid dysfunction and tobacco use in patients with PPP.

A clinical feature associated with polymorphisms of the TNF region in Japanese patients with palmoplantar pustulosis

We investigated the association of polymorphisms in the tumor necrosis factor (TNF) microsatellite as well as the promoter region of the TNFA gene and the TNFB gene with palmoplantar pustulosis (PPP). In order to clarify the heterogeneity of this disease, we performed a tonsillar provocation test on 78 patients and divided them into two groups according to the results; provocation positive (PP; n = 38) and provocation negative (PN; n = 40). We found that the phenotype frequency of the TNFB2 allele of the TNFB gene in the PN group was significantly higher than in controls (p = 0.0022, corrected p = 0.0044). There was also a significant increase in the frequency of allele B of the TNFA gene (TNFApB) in the PN group when compared with controls (p = 0.0049, corrected p = 0.025). Although there are no significant differences in the frequency of TNFa microsatellites, the frequency of the TNFd7 allele increased and that of the TNFd4 allele decreased in the PN group. An extended haplotype analysis revealed that the TNFd7-TNFApA-TNFB2 haplotype was more frequent in the PN group, implying that the PN group is associated with a low level of TNF-alpha production. These results indicate that detection of polymorphisms at the TNF locus may be a marker for determination of the heterogeneity of the disease, and that the allelic variation may influence the susceptibility.

Genetic analysis of PSORS1 distinguishes guttate psoriasis and palmoplantar pustulosis

The PSORS1 locus in the major histocompatibility complex region is the major genetic determinant for psoriasis vulgaris. Within the PSORS1 region reside at least three potential candidate genes for psoriasis susceptibility. Specific allelic variants of the genes HLA-Cw*6, HCR*WWCC, and CDSN*5 are strongly associated with psoriasis vulgaris and are in strong linkage disequilibrium with each other. We have genotyped the three psoriasis vulgaris susceptibility alleles of the PSORS1 locus in two clinical variants of psoriasis (guttate psoriasis and palmoplantar pustulosis) to study whether PSORS1 is also involved in the pathogenesis of these variants. We also asked whether these two clinical subgroups could help us to distinguish the causative gene within the high-risk PSORS1 haplotype. The association of guttate psoriasis with the three PSORS1 susceptibility alleles was similar and even stronger than seen with psoriasis vulgaris. Palmoplantar pustulosis, however, did not show association with any of the three candidate genes at this locus. Finally, no correlation with the age of onset for disease was observed. Our results show conclusively that psoriasis vulgaris and guttate psoriasis have a similar genetic basis for their association to PSORS1, whereas palmoplantar pustulosis appears to be a distinct disorder.