Psoriatic Dactylitis: Current Perspectives and New Insights in Ultrasonography and Magnetic Resonance Imaging

Advantages of ultrasound imaging for the early diagnosis of psoriatic arthritis in patients with moderate to severe psoriasis

Background

Psoriatic arthritis (PsA) is an immune-mediated form of chronic inflammatory arthritis associated with psoriasis (PsO). It constitutes a significant comorbidity of PsO and is distinguished by the presence of widespread musculoskeletal inflammation.

Objective

The aim of this study is to precisely detect asymptomatic PsA using ultrasound (US) examinations and to distinguish between various stages of PsO.

Methods

All patients with moderate-to-severe PsO, who consented to undergo musculoskeletal US examinations during their hospitalization between September 2020 and January 2022, were enrolled in the study. We compared patients' demographic characteristics, comorbidities, disease duration, relevant laboratory parameters, and musculoskeletal US findings.

Results

A total of 547 patients with PsO were included in the study, and 114 of them received a diagnosis of PsA. Furthermore, 16.45 % of patients with moderate to severe PsO displayed subclinical PsA. We observed a significantly higher frequency of abnormal US findings in patients with PsA compared to those without PsA, with a sensitivity of 95.61 % and a specificity of 79.22 %. Additionally, the incidence of enthesitis and synovitis varied significantly between PsA and non-PsA patients, and they were identified as independent variables predicting the presence of PsA. Furthermore, the interphalangeal joint, knee joint, and calcaneal tendon were the most frequently affected areas in PsA, as indicated by the observed US changes.

Conclusion

Ultrasound examination proves to be a valuable tool for detecting subclinical PsA, facilitating early screening of the condition. Particular attention should be directed towards changes in the interphalangeal joint, knee joint, and calcaneal tendon when reviewing ultrasound images of asymptomatic patients.

High-resolution ultrasound imaging of elementary lesions in dactylitis

OBJECTIVE

The aim of the present study was to illustrate the (potential) diagnostic role of high resolution US images in assessing the elementary lesions of dactylitis.

METHODS

Using high-frequency US machines/probes, we matched the micro-anatomical cadaveric architecture of the digit with multiple sonographic findings of dactylitis. High-sensitive color/power Doppler assessments have also been performed to evaluate the digital microvasculature.

DISCUSSION

Modern US equipment/features guarantee prompt and in-depth B-mode and color/power Doppler imaging of tiny anatomical structures of the digit which are usually not properly visible with standard US machines. More specifically, hypervascularization of the digital subcutaneous tissue, fibrous pulleys of flexor tendons, dorsal synovial pads as well as pathological changes of the distal entheseal anchorage network can be accurately detected.

CONCLUSION

In clinical practice, high-end US equipment can be used to accurately assess the digits in patients with dactylitis. This way, simple and convenient sonographic diagnosis of different elementary lesions can be timely established.

Osteoarthritis versus psoriasis arthritis: Physiopathology, cellular signaling, and therapeutic strategies

Osteoarthritis and psoriasis arthritis are two degenerative forms of arthritis that share similar yet also different manifestations at the histological, cellular, and clinical levels. Rheumatologists have marked them as two entirely distinct arthropathies. Given recent discoveries in disease initiation and progression, potential mechanisms, cellular signaling pathways, and ongoing clinical therapeutics, there are now more opportunities for discovering osteoarthritis drugs. This review summarized the osteoarthritis and psoriasis arthritis signaling pathways, crosstalk between BMP, WNT, TGF-β, VEGF, TLR, and FGF signaling pathways, biomarkers, and anatomical pathologies. Through bench research, we demonstrated that regenerative medicine is a promising alternative for treating osteoarthritis by highlighting significant scientific discoveries on entheses, multiple signaling blockers, and novel molecules such as immunoglobulin new antigen receptors targeted for potential drug evaluation. Furthermore, we offered valuable therapeutic approaches with a multidisciplinary strategy to treat patients with osteoarthritis or psoriasis arthritis in the coming future in the clinic.

Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) comprises a group of heterogenous disorders characterized by childhood-onset chronic joint inflammation. It is the most common rheumatologic disease in the pediatric population and an important cause of chronic illness in children. Early recognition and treatment are vital to prevent sequelae of uncontrolled inflammation on the developing skeleton. JIA can have significant complications that general pediatricians should be aware of, especially uveitis, which can be insidious and asymptomatic in very young children, and macrophage activation syndrome, which can be life-threatening if not recognized and appropriately treated. Although advances have been made in the past few decades, the etiology of JIA remains incompletely understood. Efforts are underway to refine the classification of JIA. The currently accepted classification scheme identifies subsets of JIA that are important clinically in terms of prognosis and tailoring treatment approaches. However, it is limited in identifying homogenous groups of children with early childhood onset and antinuclear antibody positivity, which may have different pathogenic mechanisms that could be important in developing more targeted and effective treatment approaches in the future. Treatment strategies for JIA have changed significantly in recent years with the availability of multiple newer targeted therapies, often modeled after medications used in adult-onset forms of arthritis. These treatments, and likely many others to come, have markedly improved symptom control and reduced complications in patients with JIA.

Rare case of Lyme borreliosis in a patient presenting with dactylitis and skin rash

An immunocompetent male in his 70s was diagnosed with psoriatic arthritis based on dactylitis, onycholysis of the nails and scalp psoriasis. He was treated with corticosteroids, methotrexate and local corticosteroid injections without improvements in his symptoms. When tumor necrosis factor-alpha inhibitor treatment was introduced, the symptoms worsened and dactylitis of all digits and a bluish-red rash were observed on the extensor side of the left hand and arm. At this point, a skin biopsy was performed showing histopathological changes compatible with Lyme borreliosis and serum contained IgG antibodies against Borrelia burgdorferi It was concluded that he was suffering from acrodermatitis chronica atrophicans (ACA) and Lyme dactylitis. Ten days of phenoxymethylpenicillin treatment was initiated, and after 2 weeks, the dactylitis and ACA had regressed substantially. After 6 months, both had resolved. This case emphasises the need for clinical reassessment, when treatment is not effective.

The role of trauma and isomorphic reaction in the pathogenesis of psoriatic arthritis

The role of biomechanical stress and trauma in the initiation of inflammation of the joints and periarticular structures in psoriatic arthritis (PA) is currently not fully understood. Soft tissues and joints are the target for constant biomechanical stress and microtrauma, leading to inflammation. There is an opinion that this inflammation in PA is due to an analogue of the skin isomorphic reaction that develops in the skin of psoriatic patients in response to trauma. Some authors have called this reaction the deep Koebner phenomenon. It is assumed that the early, preclinical phase of psoriatic arthritis may be based on inflammation of the enthesis as a response to microtrauma, and explained by the proximity of the entheses and the articular membranes. Detection of early changes in entheses in psoriatic patients, including those who do not have complaints from the musculoskeletal system, is of great importance for the early diagnosis of psoriatic arthritis. In the literature review, the sources for the period 20102021 were studied, devoted to the role of the isomorphic reaction and microtraumatization in the pathogenesis of PA, as well as the role of various imaging methods for the early diagnosis of enthesitis in psoriatic patients.

Psoriatic arthritis

Psoriatic arthritis (PsA) is a type of inflammatory arthritis that is included within the spondyloarthritis, a group of rheumatological diseases characterized by different clinical manifestations and associated comorbidities, that can compromise the quality of life of patients. The diagnosis of PsA is sometimes difficult due to an enormous clinical and radiological variability, including six different domains of involvement: peripheral joint, axial skeleton, skin psoriasis, nail psoriasis, enthesitis and dactylitis. Currently, there are no biomarkers that allow the detection of PsA in patients with psoriasis, so a high level of suspicion is important, mainly by dermatologists, but also by other specialists, such as family doctors. Advances in the knowledge of new immunological mechanisms and joint management by rheumatologists and dermatologists have made it possible to improve the therapeutic approach in patients with PsA.

Dactylitis is associated with more severe axial joint damage and higher disease activity in axial psoriatic arthritis

Objective

To investigate the association of dactylitis with disease activity and the severity of radiological damage in patients with axial psoriatic arthritis (AxPsA).

Methods

Patients with AxPsA met the classification criteria (CASPAR) were recruited. Clinical data, radiographic changes and disease activity in AxPsA patients with or without dactylitis were compared using t-tests, Mann-Whitney U test or Kruskal-Wallis test for continuous variables, Ⲭ2 or Fisher exact tests for categorical variables and logistic regression analysis for the association between dactylitis and radiographic damage.

Results

A total of 186 AxPsA patients were analysed and dichotomized by the presence or absence of dactylitis. Patients with dactylitis had higher levels of CRP, ESR, NLR and PLR than those who did not have (PCRP=0.004; PESR=0.006; PNLR=0.035; PPLR=0.020). In addition, dactylitic AxPsA patients also had higher TJC, SJC, DAPSA and HAQ (P<0.001), and higher score of DAS28, ASDAS, BASFI and BASDAI (P<0.05), while less patients met MDA and DAPSA-LDA criteria (P<0.05). Consistently, they had more severe radiological damage (P< 0.05), higher sacroiliac scores (OR 2.076, 95%CI 1.137 to 3.791, P=0.017) and more significant reduction in BMD (OR 2.422, 95%CI 1.342 to 4.372, P=0.003). No statistical differences were observed for HLA-B27 and LEI between these two group patients. Notably, only half of dactylitic AxPsA patients had inflammatory back pain.

Conclusion

Our study demonstrated that dactylitic AxPsA patients had higher disease activity and more severe joint damage compared those without dactylitis. Careful examination of axial involvements and proper management are recommended.

The Emerging Era of Interventional Imaging in Rheumatology: An Overview During the Coronavirus Disease-2019 (COVID-19) Pandemic

Imaging has long been taking its place in the diagnosis, monitor, and prognosis of rheumatic diseases. It plays a vital role in the appraisal of treatment. Key progress in the clinical practice of rheumatology is the innovation of advanced imaging modalities; such as musculoskeletal ultrasound (MSUS), computerized tomography (CT) and magnetic resonance imaging (MRI). These modalities introduced a promising noninvasive method for visualizing bone and soft tissues to enable an improved diagnosis. The use of MSUS in rheumatology is considered a landmark in the evolution of the specialty and its ease of use and many applications in rheumatic diseases make it a forerunner instrument in the practice. The use of MSUS among rheumatologists must parallel the development rate of the excellence revealed in the specialty. Moreover, innovative interventional imaging in rheumatology (III-R) is gaining fame and key roles in the near future for a comprehensive management of rheumatic diseases with precision. This review article throws light on the emergence of these robust innovations that may reshape the guidelines and practice in rheumatology, in particular, efforts to enhance best practice during the coronavirus disease 2019 (COVID-19) pandemic are endorsed.

[Benefit of ultrasound in the phenotype recognition of psoriatic arthritis]

OBJECTIVE

To explore the difference in phenotype recognition of PsA patients in two clinical scenarios, physical examination with and without ultrasound assessment.

METHODS

PsA patients who visited the rheumatology and clinical immunology department of Peking University First Hospital between January 2010 and October 2020, with complete data of clinical and ultrasound assessment were enrolled. The phenotypes were first identified based on physical examination only, and then combined with enthesitis and dactylitis shown on power doppler and gray-scale ultrasound. The phenotype groupings without and with ultrasound assessment were presented with Wayne diagram. The distributions of different clinical phenotypes were compared by using χ² test or Fisher's exact test. The differences of clinical phenotypes with and without ultrasound assessment were compared by using Wilcoxon signed rank test.

RESULTS

A total of 227 patients with PsA were enrolled with one or more clinical domains. Physical examination revealed that psoriasis was in 209 (92.1%, 209/227) patients, nail involvement in 98 (43.2%, 98/227) patients, peripheral arthritis in 219 (96.5%, 219/227) patients, axial involvement in 25 (11.0%, 25/227) patients, dactylitis in 80 (35.2%, 80/227) patients, and enthesitis in 18 (7.9%, 18/227) patients. Besides 18 patients with clinical enthesitis, ultrasound scan revealed acute enthesitis in 80 patients, with hypoechogenicity (55 cases), tendon thickening (62 cases), and presence of Doppler signals (48 cases). Similarly, dactylitis on ultrasound was found in 18 patients besides those patients with clinical dactylitis. Compared with the phenotypes recognized based on physical examination only, the additional ultrasound assessment revealed that the most common phenotypes, peripheral arthritis was significantly less frequently recognized (49.8% vs. 27.8%, P < 0.001), however on the other hand, the proportion of the patients with peripheral arthritis and enthesitis was significantly increased (4.4% vs. 18.1%, P < 0.001). The phenotype of peripheral arthritis combined with enthesitis, and dactylitis was also dramatically increased (1.8% vs. 17.6%, P < 0.001).

CONCLUSION

Ultrasound is a useful tool to identify enthesitis and dactylitis. With the aid of ultrasound assessment, rheumatologists can better identify the lesions of PsA, accurately identify the phenotypes, and further guide the subsequent treatment.