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

Paediatric pustulotic arthro-osteitis patient with an IL36RN variant, heterozygous c.115+6T>C, who was successfully treated with tonsillectomy: A case report and literature review

Pustulotic arthro-osteitis (PAO) is an infrequent condition, with its manifestation in children being even rare. Some reports propose an association between genetic variants and the onset of PAO. Currently, no definitive treatment protocol exists for paediatric patients with PAO. In this study, we present the paediatric case of PAO with an IL36RN variant who was successfully treated with tonsillectomy.

Treatment and monitoring of SAPHO syndrome: a systematic review

BACKGROUND AND OBJECTIVES

Synovitis acne pustulosis hyperostosis osteitis (SAPHO) is a rare heterogeneous disease of unknown aetiopathology. Externally validated and internationally agreed diagnostic criteria or outcomes and, as a result, prospective randomised controlled trials in SAPHO are absent. Consequently, there is no agreed treatment standard. This study aimed to systematically collate and discuss treatment options in SAPHO.

METHODS

Following 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' guidance, a systematic literature search was conducted using PubMed, Scopus and Web of Science databases. Prospective clinical studies and retrospective case collections discussing management and outcomes in SAPHO involving five or more participants were included. Articles not published in English, studies not reporting defined outcomes, and studies solely relying on patient-reported outcomes were excluded.

RESULTS

A total of 28 studies (20 observational, 8 open-label clinical studies) reporting 796 patients of predominantly European ethnicity were included. Reported therapies varied greatly, with many centres using multiple treatments in parallel. Most patients (37.1%) received non-steroidal anti-inflammatory drugs alone or in combination. Bisphosphonates (22.1%), conventional (21.7%) and biological (11.3%) disease-modifying antirheumatic drugs were the next most frequently reported treatments. Reported outcomes varied and delivered mixed results, which complicates comparisons. Bisphosphonates demonstrated the most consistent improvement of osteoarticular symptoms and were associated with transient influenza-like symptoms. Paradoxical skin reactions were reported in patients treated with TNF inhibitors, but no serious adverse events were recorded. Most treatments had limited or mixed effects on cutaneous involvement. A recent study investigating the Janus kinase inhibitor tofacitinib delivered promising results in relation to skin and nail involvement.

CONCLUSIONS

No single currently available treatment option sufficiently addresses all SAPHO-associated symptoms. Variable, sometimes descriptive outcomes and the use of treatment combinations complicate conclusions and treatment recommendations. Randomised clinical trials are necessary to generate reliable evidence.

Successful treatment of pustulotic arthro-osteitis with amoxicillin: A case report and review of the literature

Palmoplantar pustulosis (PPP) is a chronic skin inflammatory disease characterized by sterile pustules on the palms and soles. Pustulotic arthro-osteitis (PAO) is a major comorbidity of PPP, frequently affecting the anterior chest wall. PPP and PAO are thought to be closely associated with focal infection. We report a female in her 40s who developed pustules on her palms and soles with tenderness of both sternoclavicular and left sacroiliac joints, which were not improved with non-steroidal anti-inflammatory drugs. Of note, she showed a great response to amoxicillin, resulting in the almost complete resolution of her skin lesions and arthralgia. We also reviewed previous reports to learn more about the potential therapeutic options of antibiotics for PAO.

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.

Clinical and therapeutic diversity in adult chronic nonbacterial osteomyelitis (CNO) of the sternocostoclavicular region: a meta-analysis

OBJECTIVES

Chronic nonbacterial osteomyelitis (CNO) is a rare inflammatory bone disease. The distinct CNO subtype that affects the anterior chest wall is descriptively named sternocostoclavicular hyperostosis (SCCH) and mainly occurs in adults. Literature on CNO/SCCH is scattered and lacks diagnostic and therapeutic consensus.

METHODS

Systematic review and meta-analysis aiming to characterize clinical presentation and therapeutic modalities applied in adult CNO/SCCH patients. Untransformed numerical data and double-arcsine transformed proportional data were pooled in a random effects model in R-4.0.5; proportions were reported with 95% CI.

RESULTS

Forty studies were included, containing data on 2030 and 642 patients for aim 1 and 2, respectively. A female predisposition (67%, 95% CI 60, 73) and major diagnostic delay (5 years 95% CI 3, 7) were noted. Clinical presentation included chest pain (89%, 95% CI 79, 96) and swelling (79%, 95% CI 62, 91). Patients suffered from pustulosis palmoplantaris (53%, 95% CI 37, 68), arthritis (24%, 95% CI 11, 39) and acne (8%, 95% CI 4, 13). Inflammatory markers were inconsistently elevated. Autoantibody and HLA-B27 prevalence was normal, and histopathology unspecific. Increased isotope uptake (99%, 95% CI 96, 100) was a consistent imaging finding. Among manifold treatments, pamidronate and biologicals yielded good response in 83%, 95% CI 60, 98 and 56%, 95% CI 26, 85, respectively.

CONCLUSION

CNO/SCCH literature proves heterogeneous regarding diagnostics and treatment. Timely diagnosis is challenging and mainly follows from increased isotope uptake on nuclear examination. Biopsies, autoantibodies and HLA status are non-contributory, and biochemical inflammation only variably detected. Based on reported data, bisphosphonates and biologicals seem reasonably effective, but due to limitations in design and heterogeneity between studies the precise magnitude of their effect is uncertain. Fundamentally, international consensus seems imperative to advance clinical care for CNO/SCCH.

Pro and contra: is synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) a spondyloarthritis variant?

PURPOSE OF REVIEW

The purpose of this review is to present the up-to-date evidence on the epidemiology, pathogenesis, musculoskeletal manifestations, and imaging of the synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and to discuss its relationship with spondyloarthritis (SpA).

RECENT FINDINGS

SAPHO is a rare inflammatory disorder of bone, joints, and skin, with a worldwide distribution that predominantly affects the middle-age adults. The hallmark of the syndrome is a constellation of sterile inflammatory osteitis, hyperostosis, and synovitis involving the anterior chest wall, associated with acneiform and neutrophilic dermatoses, such as palmoplantar pustulosis and severe acne. The axial skeleton, sacroiliac, and peripheral joints can be involved in a similar fashion to SpA. The pathogenesis of the syndrome is multifactorial. The diagnosis is mainly based on the clinical and typical radiological features. The treatment approach is based on the off-label use of antibiotics, bisphosphonates, disease-modifying antirheumatic drugs, and anticytokine biologics.

SUMMARY

The SAPHO syndrome shares common features with SpA-related diseases, yet also shows some unique pathogenetic and clinical features. The nosology of SAPHO remains a subject of controversy, awaiting further research into the pathogenetic and clinical aspects of this syndrome. A better understanding of these aspects will improve the diagnostics and clinical care of patients with SAPHO.

Clinical characteristics of pustulotic arthro-osteitis in Korea

Pustulotic arthro-osteitis (PAO) has been studied primarily in Japan. However, there is a lack of research regarding its clinical features among large populations in other countries and it is often believed to be similar to psoriatic arthritis (PsA). Although the association between psoriasis (PsO) and palmoplantar pustulosis (PPP) is debatable, differences in the clinical characteristics between PsA and PAO might support the notion that PsO and PPP are distinct entities. This study aimed to investigate the clinical characteristics of PAO in Korean patients and to compare them with those of PsA. We retrospectively reviewed the medical records of patients diagnosed with PPP, PAO, and PsA. Among 266 patients with PPP, 13.2% had PAO. Unlike Japanese patients with PAO, Korean patients had a relatively lower involvement of the chest wall. PAO patients demonstrated lower age of onset, higher proportion of females, and higher severity of cutaneous eruptions compared to PPP patients without PAO, but the differences were not statistically significant. Female predominance was prominent in PAO compared to PsA. Cutaneous eruptions occurred earlier than joint symptoms in 83.5% of the patients with PsA and in 42.9% of the patients with PAO. PAO involved axial joints more frequently compared to PsA, especially the chest wall and spine. PsA mainly involved the peripheral joints, especially the metacarpophalangeal joints and distal interphalangeal joints of the hands and feet. In conclusion, PAO and PsA exhibited different demographics and locations of joint involvement, supporting the notion that PPP and PsO are separate disorders. Many PAO patients presented with joint symptoms before the appearance of skin eruptions, underlining the important role of dermatologists in recognizing PAO among PPP patients. Physicians should be aware of the characteristics of PAO while treating patients with PPP.

SAPHO Syndrome and Pustulotic Arthro-Osteitis (PAO)

Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis (SAPHO) syndrome is a rare inflammatory osteo-articular disorder, which encompassed many diseases, including pustulotic arthro-osteitis (PAO). Bone and joint manifestations, including osteitis, synovitis and hyperostosis, are the hallmark of the SAPHO syndrome and affect a variety of regions of the body. Recent GRAPPA survey indicated that more than 80 percent of cases of SAPHO syndrome in Japan were thought to be PAO, originally proposed by Sonozaki et al. in 1981, whereas severe acne was the most commonly reported skin ailment amongst participants with SAPHO syndrome in Israel. SAPHO syndrome is a rare disease and adequate data regarding its prevalence remains unavailable, whereas prevalence of PPP was reported to be 0.12 % in Japan and 10-30% of patients with PPP had PAO. SAPHO syndrome and PAO are predominantly found in patients in the third through fifth decades of life, and a female predominance are seen in both groups. The diagnosis of SAPHO syndrome/PAO is typically made by a rheumatologist or dermatologist. Identification of a variety of the clinical, radiological, and laboratory features outlined, as well as diagnostic criteria, are used to make the diagnosis. Goals for treating patients with SAPHO syndrome/PAO seek to maximize health-related quality of life by improving skin and articular symptoms, preventing structural changes and destruction, and normalizing physical function and social participation. Finally, we review the non-pharmacological (ie: smoking cessation and controlling focal infections) and pharmacological managements including NSAIDs, bisphosphonates, cs DMARDs, bDMARDs, and other treatments for SAPHO syndrome/PAO.

A Case Report of Improved Palmoplantar Pustulosis following Periodontal Treatment and Possible Association with Diminished Systemic Subclinical Inflammation

Palmoplantar pustulosis (PPP) is a recurrent pustular dermatosis located on the palms and soles. Focal infection may exacerbate the symptoms of PPP, but the etiology is not fully clear. A 56-year-old woman with PPP was diagnosed with severe chronic periodontitis. Initial treatment for periodontitis combined with topical application of antibiotics and surgical treatment was performed. In this case, attention was paid to the relevance of systemic inflammation caused by periodontitis with the clinical symptoms of PPP. With periodontal treatment, the symptoms of PPP and periodontitis, high-sensitivity C-reactive protein (hs-CRP) level, and periodontal inflamed surface area (PISA) improved. This case highlights the importance of comprehensive dental examinations, including those for oral infections, such as periodontitis and other unrecognized sources of infection, and dental treatment in the overall management of PPP.

Sustained efficacy and safety of guselkumab in patients with palmoplantar pustulosis through 1.5 years in a randomized phase 3 study

The safety and efficacy of guselkumab for palmoplantar pustulosis (PPP) have been established through week (W)52; however, no sufficient information is available beyond 1 year. This study was conducted to assess the efficacy and safety of guselkumab through W84, and to explore factors associated with the sustainability of its efficacy in Japanese PPP patients. Patients received guselkumab 100 or 200 mg at W0, W4, W12, and every 8 weeks (q8w) until W60, or placebo at W0, W4, and W12. At W16, patients receiving placebo were re‐randomized to receive guselkumab 100/200 mg at W16, W20, and q8w until W60. Efficacy end‐points included PPP Area and Severity Index (PPPASI), PPP Severity Index (PPSI), Physician’s Global Assessment scores, and patient reported outcomes (PRO) (Dermatology Life Quality Index, EuroQoL‐5 Dimensions, and 36‐item Short Form Health Survey). Post‐hoc comparison of patient characteristics was performed between PPPASI‐75/90 responders and non‐responders at W60, and sustained responders and non‐responders at W84. Safety was evaluated through W84. A total of 45, 43, 21, and 24 patients from the guselkumab 100 mg, guselkumab 200 mg, placebo→guselkumab 100 mg, and placebo→guselkumab 200 mg groups, respectively, completed the study through W84. Overall, the mean improvement in the guselkumab groups from baseline in the PPPASI and PPSI total scores at W84 was ~79% and ~66%, respectively. All PRO improved through W84. The proportion of responders through W60 was higher in patients who had not received prior phototherapy and non‐biologic systemic therapy for PPP. Non‐smokers and patients with no prior non‐biologic systemic treatment tended numerically towards sustained efficacy through W84. The majority of treatment‐emergent adverse events (TEAE) were mild to moderate (~88%) with low incidence of serious TEAE (7.6%). Overall, guselkumab showed sustained efficacy and safety with improvement in the health‐related quality of life through W84 in Japanese PPP patients.

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.

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.

Guselkumab for the Treatment of Palmoplantar Pustulosis: A Japanese Perspective

Palmoplantar pustulosis (PPP) is a chronic inflammatory disorder characterized by sterile pustules predominantly involving the palms and soles. PPP is refractory to various therapies such as topical ointment, oral medicine, and phototherapies. Pustulotic arthro-osteitis (PAO) is a major comorbidity of PPP that severely impairs patients’ quality of life. Recently, guselkumab, a monoclonal antibody against IL-23, has been available for the treatment of PPP in Japan. The purpose of the present review is to describe the characteristics of Japanese PPP patients and biologic therapy of PPP/PAO using guselkumab. Most Japanese dermatologists consider PPP as a distinct entity and co-existence of PPP and psoriasis is rare. However, outside Japan, PPP is often considered to be palmoplantar psoriasis, and extra-palmoplantar lesions associated with PPP are regarded as psoriasis. PPP develops or exacerbates either with or without arthralgia, following focal infections, such as tonsillitis, odontogenic infection, and sinusitis. Treatment of focal infection results in dramatic effects on cutaneous lesions as well as joint pain. By contrast, we sometimes see patients whose skin/joint symptoms do not improve after treatment of focal infection, whose focus of infection cannot be identified even in a detailed examination, and/or who refuse tonsillectomy even if strongly recommended. Such cases are considered to be indications of biologics. In this review, clinical features, pathophysiology and guselkumab therapy are discussed.

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.