Subclinical enthesopathy of extensor digitorum tendon is highly prevalent and associated with clinical and ultrasound alterations of the adjacent fingernails in patients with psoriatic disease

A novel nomogram to predict psoriatic arthritis in patients with plaque psoriasis

OBJECTIVE

To construct a predictive model for Psoriatic Arthritis (PsA) based on clinical and ultrasonic characteristics in patients with plaque psoriasis (PsP).

PATIENTS AND METHODS

Demographic, clinical, and ultrasound data were collected from patients with PsP and PsA between May 2019 and December 2022.

RESULTS

A total of 212 patients with PsP and 123 with PsA in the training cohort, whereas the validation cohort comprised 91 patients with PsP and 49 with PsA. The multivariate logistic regression identified nail psoriasis (odds ratio [OR] 1.88, 95% CI: 1.07-3.29), synovitis (OR 18.23, 95% CI: 4.04-82.33), enthesitis (OR 3.71, 95% CI: 1.05-13.14), and bone erosion (OR 11.39, 95% CI: 3.05-42.63) as effective predictors for PsA. The area under the curve was 0.750 (95% CI, 0.691-0.806) and 0.804 (95% CI, 0.723-0.886) for the training and validation cohorts, respectively. The Hosmer-Lemeshow goodness-of-fit test showed good consistency for both the training cohort (p  =  0.970) and the validation cohort (p  =  0.967). Calibration curves also indicated good calibration for both cohorts. The DCA revealed that the predictive model had good clinical utility.

CONCLUSIONS

We have developed a quantitative, intuitive, and convenient predictive model based on nail psoriasis, synovitis, enthesitis, and bone erosion to assess the risk of PsA in patients with plaque psoriasis.

From Psoriasis to Psoriatic Arthritis: Ultrasound Insights Connecting Psoriasis with Subclinical Musculoskeletal Inflammation and the Path to Psoriatic Arthritis

PURPOSE OF REVIEW

This review summarizes the literature about the transition from psoriasis to psoriatic arthritis (PsA), focusing on musculoskeletal ultrasound (MSUS) for detecting subclinical inflammation and its role in diagnosis and triage of high-risk patients.

RECENT FINDINGS

MSUS effectively detects subclinical musculoskeletal inflammation in patients with psoriasis; however, some of these lesions are non-specific and can be found in healthy individuals. Preliminary evidence suggest that subclinical sonographic findings may predict progression to PsA in psoriasis patients. MSUS can also improve referrals' accuracy and its integration in the PsA classification criteria may improve early PsA detection. MSUS is a valuable tool for detecting subclinical abnormalities in psoriasis patients, which indicate an increased likelihood of progressing to PsA. Its integration into referral protocols and clinical use could improve PsA diagnosis. We propose an MSUS-inclusive algorithm for PsA referrals and triage, which requires validation. The potential of early intervention in reducing PsA progression in psoriasis patients with subclinical inflammation remains to be established.

Ultrasonographic Evaluation of Nail Involvement in Patients With Axial Spondyloarthritis

OBJECTIVES

This study aimed to evaluate the nail units of patients with axial spondyloarthritis (ax-SpA) using ultrasound and to identify any subclinical changes. We also aimed to examine the relationship between clinical enthesitis scores and nail involvement in patients with ax-SpA.

METHODS

The study included 40 patients with ax-Spa, 40 patients with psoriatic arthritis (PsA), and 40 healthy controls. The thickness of the nail plates, morphological changes, the thickness of the proximal nail units, the thickness of the nail beds, and power Doppler signal intensities were evaluated and compared. Maastricht Ankylosing Spondylitis Enthesitis Score and Spondyloarthritis Research Consortium of Canada Enthesitis Index were also evaluated in patients with ax-SpA.

RESULTS

There was no significant difference between the thickness of the nail plates of the three groups (P > .05). The first nail bed thickness of ax-SpA cases was significantly higher than the control group (P = .046), and the fourth and fifth nail proximal unit thicknesses of the control group were significantly lower than the ax-SpA and PsA groups (P = .023, P = .017). We also found that the Wortsman scores of the cases with PsA were significantly higher than the ax-SpA and control groups (P = .0001).

CONCLUSION

The thickness of the proximal nail unit adjacent to the insertion of the digital extensor tendon, which is considered as the enthesis area, is similar to the patients with PsA in patients with ax-SpA, especially in the fourth and fifth fingers compared to the control group. On the other hand, almost no structural changes in nail plates were observed in patients with ax-SpA group.

Nail Ultrasound in Psoriasis and Psoriatic Arthritis-A Narrative Review

Ultrasonography has advantages for assessing psoriatic arthritis (PsA) due to its ability to evaluate several targets, including joints, entheses, and tendons, but also skin and nails. Although ultrasound is widely used in PsA, nail ultrasound, despite its potential as a non-invasive method for the early detection of inflammation in the nail apparatus, has low applicability in medical practice, as probes with a higher frequency are needed compared with the frequency of probes usually used. In the present article, we have narratively evaluated the studies published in the last 5 years (19 February 2018-18 February 2023) on nail ultrasound value in the diagnosis and monitoring of PsA. The studies published during this period share common measurement parameters, such as the OMERACT definition of enthesis published in 2018. We included original articles published in PubMed and Web of Science using the following search terms in all possible combinations: psoriatic arthritis, psoriasis, ultrasound, and nail. Articles were declared relevant if they presented data on nail morphology, power Doppler evaluation and nearby structure evaluation, while focusing on digitorum extensor enthesitis. In most of the studies, common morphological parameters were generally increased in patients with psoriasis or PsA and were demonstrated to change with medication. The thickness of the extensor tendon was greater in patients with PsA and psoriasis versus controls and it was correlated with nail clinical changes, especially the presence of onycholysis. The presence of PD showed large variability in healthy individuals. The link between enthesitis and nail involvement is still a subject of controversy, taking into account the latest histological findings. The use of ultrasound in the evaluation of nail and DIP enthesitis remains a challenge and an area of research in the coming years.

Are There Signs of Enthesitis in Nail Psoriasis? An Immunohistological Study of Nail Psoriasis With and Without Psoriatic Arthritis

ABSTRACT

The concept of nail psoriasis as an entheseal-driven disease has essentially been formulated on the basis of radiological findings because it is usually not possible to obtain the tissue directly from the joints. The aim of this retrospective study was to evaluate the histological features of isolated nail psoriasis with and without distal interphalangeal psoriatic arthritis (PsA), focusing on the question as to whether the fascia and adipose tissue surrounding the apex of the nail unit genuinely show an inflammatory infiltrate. In support of the nail-enthesitis theory, an ongoing inflammatory infiltrate could be expected. An immunohistochemical study was performed to evaluate the distribution and phenotype of the inflammatory infiltrate in nail psoriasis with and without PsA. This study did not show an inflammatory infiltrate in the fascia connecting the nail to the extensor tendon. CD8 and CD4 subsets were present in equal number in the nail dermis of nail psoriasis with or without PsA, which is a similar distribution to that seen in psoriatic synovium while skin psoriasis is characterized by a dermal predominance of CD4 T lymphocytes. Because of this study and recent microanatomic studies of the normal nail unit, it is possible to move away from a purely anatomic explanation of the strong association between nail psoriasis and PsA and to propose immunological factors as contributory. This study provides support for the hypothesis that CD8+ T cells play a crucial role in the pathogenesis of nail psoriasis through a pathogenic pathway similar to that of PsA and contrasting with that of the skin.

Usefulness of Ultrasound Examination in the Assessment of the Nail Apparatus in Psoriasis

The assessment of psoriatic nail changes in everyday practice is based exclusively on clinical symptoms that do not reflect the entire disease process in the nail apparatus. The use of imaging methods, especially widely available and inexpensive ultrasonography, creates the possibility of additional revealing and assessing grayscale of morphological changes of the ventral nail plate, nail bed, and matrix, as well as the attachment of the finger extensor tendon to the distal phalanx. What is more, it enables the assessment of inflammation severity in the power Doppler technique. A qualitative classification of nail plate morphological changes corresponding to the severity of psoriatic nail changes has been developed so far and attempts are being made to develop a quantitative method to assess not only the presence of changes but also the severity of inflammation. Nail ultrasonography is not commonly performed, although published studies indicate the possible use of this technique in the assessment of psoriatic changes in nail structures. It can be particularly useful in subclinical changes imaging, preceding clinical manifestation of psoriatic nail changes, enthesopathy: subclinical and in the course of psoriatic arthritis, as well as in the assessment of treatment efficacy. This review article aims to summaries the research on ultrasonography of the nail apparatus which has been carried out so far, taking into account its applicability in clinical practice.

Imaging of the Nail Unit in Psoriatic Patients - a Systematic Scoping Review of Techniques and Terminology

Background

The growing interest in the visualization of psoriatic nail unit changes has led to the discovery of an abundance of image characteristics across various modalities.

Objective

To identify techniques for non‐invasive imaging of nail unit structures in psoriatic patients and review extracted image features to unify the diverse terminology.

Methods

For this systematic scoping review, we included studies available on PubMed and Embase, independently extracted image characteristics, and semantically grouped the identified features to suggest a preferred terminology for each technique.

Results

After screening 753 studies, 67 articles on the visualization of clinical and subclinical psoriatic changes in the nail plate, matrix, bed, folds and hyponychium were included. We identified 4 optical and 3 radiological imaging techniques for the assessment of surface (dermoscopy [n = 16], capillaroscopy [n = 12]), sub‐surface (ultrasound imaging [n = 36], optical coherence tomography [n = 4], fluorescence optical imaging [n = 3]), and deep‐seated psoriatic changes (magnetic resonance imaging [n = 2], positron emission tomography‐computed tomography [n = 1]). By condensing 244 image feature descriptions into a glossary of 82 terms, overall redundancy was cut by 66.4% (37.5%–77.1%). More than 75% of these image features provide additional disease‐relevant information that is not captured using conventional clinical assessment scales.

Conclusions

This review has identified, unified, and contextualized image features and related terminology for non‐invasive imaging of the nail unit in patients with psoriatic conditions. The suggested glossary could facilitate the integrative use of non‐invasive imaging techniques for the detailed examination of psoriatic nail unit structures in research and clinical practice.

Chronic Plaque Psoriasis in Poland: Disease Severity, Prevalence of Comorbidities, and Quality of Life

The epidemiology of psoriasis has not been widely assessed in Polish population so far. This study aimed to investigate psoriasis epidemiological situation by evaluating disease course and severity, management, comorbidities, environmental factors, and knowledge about this disorder among psoriatic patients in Poland. A cross-sectional cohort population-based study enrolled 1080 psoriatic patients and 1200 controls. The mean age of psoriasis onset was 27.6 years; 78.24% had type I psoriasis. Positive family history of psoriasis was reported in 44.81% of patients, whereas itch was reported in vast majority of patients (83.33%). Based on PASI score moderate psoriasis was the most common in studied group (mean 12.63 ± 9.33, range 0−67.2). The DLQI score (12.01 ± 7.41, range 0−30.0) indicated a very large effect of psoriasis on the quality of life. Hypertension was the most prevalent comorbidity (33.80%), followed by obesity (16.85%) and dyslipidemia (11.85%). Stress was the foremost cause of disease exacerbation (66.20%); however, infections (44.07%) and seasonal changes (45.09%) had also an impact on the course of psoriasis. Psoriatic patients were more often smokers (37.59%) vs. general population (27.50%; p < 0.0001). In conclusion, epidemiological studies help clinicians in better disease and patient understanding, which may translate into better management and patient compliance.

Improving Imaging Modalities in Early Psoriatic Arthritis: The Role of Ultrasound in Early Diagnosis of Psoriatic Arthritis

Objective: Despite recent advances, early diagnosis of psoriatic arthritis (PsA) remains a challenge in clinical practice. Ultrasound (US) could be a useful tool for the diagnosis and management of PsA. The objective of this review was to determine the role of US in early diagnosis of PsA.

Methods: We have performed a literature review aiming to evaluate studies on US findings in psoriasis and their predictive value of progression to PsA, as well as studies on US features specific for PsA in comparison with other conditions.

Results: A total of 40 studies were included. Sixteen studies assessed US findings in psoriasis, of which only 3 prospectively evaluated the role of US in predicting progression to PsA. Patients with PsA had a greater frequency of US abnormalities, in particular enthesitis and Power Doppler(PD) signal compared to patients with psoriasis only. In the longitudinal studies, psoriatic patients with higher enthesopathy scores at baseline were more likely to progress to PsA. Twenty-four studies evaluated US abnormalities in PsA and compared them to other conditions. Most specific US features that distinguish PsA from psoriasis were PD signal and erosions in joints and entheses. Extra-synovial changes, including peri-tendinous dermal soft tissue oedema with associated PD signal and flexor tendon enthesopathy, as well as thickening of the pulleys in the flexor tendons were highly characteristic for PsA, as they were frequently found in PsA patients, but in none of the RA patients. US-detected entheseal abnormalities in particular erosions and PD signal were more frequent in patients with PsA compared to fibromyalgia.

Conclusion: Despite the wide use of US in PsA, more research is needed to identify predictive factors of progression to PsA in patients with psoriasis, as well as to determine most specific US features that differentiate PsA from other conditions.

The relationship between the nail and systemic enthesitis in psoriatic arthritis

Objective

Psoriatic nail disease is more common in PsA than in isolated skin psoriasis (PsO). The nail is closely integrated to the DIP joint entheses. US data have shown that those patients with nail disease in PsO are more likely to have systemic enthesitis. We examined whether there was a relationship between nail disease, DIP enthesitis and systemic enthesitis in established PsA.

Methods

Forty-six PsA participants with nail disease underwent US scanning of the nail unit and the DIP entheses along with peripheral entheseal sites according to the Madrid sonographic enthesitis index (MASEI).

Results

At the finger level, there was a mild to moderate correlation between nail US changes and both clinical nail disease and DIP enthesis changes (DIP US) [Spearman correlation (r_S) = 0.30, P < 0.001 and r_S = 0.16, P < 0.001, respectively]. At the patient level, there was a moderate correlation between the nail US score and nail psoriasis severity index score and DIP US (r_S = 0.33, P = 0.024 and r_S = 0.43, P = 0.003, respectively). At the patient level, there was also a positive correlation between a higher nail US score and the active peripheral enthesitis score (MASEI-active) (r_S = 0.35, P = 0.018). When power Doppler was part of nail US score, similar results were demonstrated at both the finger and patient levels.

Conclusion

This study has demonstrated the utility of nail US imaging and the close relationship, on scanning, between the DIP entheses and the nail unit. In PsA, we have seen a correlation between active US changes at the nail and peripheral enthesitis, which requires further analysis.

Trial registration

ClinicalTrials.gov, https://clinicaltrials.gov, NCT03955861.

Focal Synovial Inflammation Versus Enthesitis Theory in Distal Psoriatic Arthritis: A Pioneer Histopathologic Study

ABSTRACT

The aim of this analysis was to re-examine the classical concept of distal interphalangeal joint (DIP) psoriatic arthritis (PsA) as an entheseal-driven disease. Two cadaveric fingers with severe psoriatic arthritis were analyzed. Our results demonstrate that inflammation of DIP PsA is multifocal without interconnection between entheses and articular cartilage of the DIP. We found a clear association between synovitis and focal loss of articular cartilage at the head of the intermediate phalanx. By contrast, the articular cartilage adjacent to the zone of severe enthesitis did not show notable damage. Fibrocartilaginous destructions of enthesis were characterized by either a multifocal lymphocytic inflammation, accompanied by osteoclastic resorption, beginning on the interface between the uncalcified and calcified fibrocartilage and then extending into the bone or a subchondral bone inflammation which insidiously destroyed first the bone and then the fibrocartilage. Some sections well showed an inflammation either mild or prominent starting at the level of vascular foramina of flexor enthesis, with secondary invading into the interface between bone and enthesis. The different anatomic sites examined showed a slight predominance of CD8+ T cells over CD4+ T cells: 52% up to 63% for CD8+ T cells vs. to 36% up to 48% for CD4+ T cells. Sparse interspersed CD1a+cells and PS100+cells were also seen with a predominance of PS100+ cells on CD1a+ cells. CD20+ B cells, plasmocytes, neutrophils, and mastocytes were absent or rare. CD123 positive cells were not observed. In DIP PsA, 3 findings predominate: (1) cartilage invasion by the thin pannus offers a more rational explanation for the focal joint destruction than does inflammation of the enthesis which is independent from articular cartilage, (2) the thick ventral plate and to a lesser extend the thin dorsal plate constitute a barrier between the inflamed entheses and the articular cartilage, and (3) an unusual form of minute vascular foramen contributes to the early stage of enthesitis. This small study suggests that DIP PsA is a complex disease. It affects anatomical micro sites which, although close, are in fact relatively independent of each other. Further studies are needed to test this hypothesis.

Ultrasonographic and resistance index evaluation of nails in psoriatic arthritis, psoriasis, and control groups: a cross-sectional study

BACKGROUND

Nail psoriasis occurs frequently in patients with psoriatic disease, it can lead to functional impairment, pain, discomfort, decreased quality of life and can also be a predictor for the development of arthritis. Early recognition of this condition can provide early and effective treatment and prevent structural impairment. This study aims to identify nail ultrasonographic characteristics in three groups: psoriasis (PsO), psoriatic arthritis (PsA) and controls patients, to determine if the ultrasonography (US) can identify early signs of nail psoriatic impairment or local inflammation. We conducted nail US to determine nail matrix resistance index (NMRI), nail bed resistance index (NBRI), and power Doppler (PD) and grayscale (GS) parameters in these 3 groups.

METHODS

Single-center, cross-sectional study. GS, PD, and spectral doppler images of bilateral 2nd and 3rd fingernails were acquired from 35 PsO, 31 PsA, and 35 controls patients. An US equipment with an 18 MHz linear transducer for GS and 8.0 MHz for PD was used. PD, NMRI, NBRI, nail plate thickness (NPT), nail bed thickness (NBT), nail matrix thickness (NMT), and morphostructural characteristics of the trilaminar structure (TS) were evaluated in saved images, blind.

RESULTS

Mean NMRI and NBRI did not differ between groups. Linear regression analysis detected no relationships between PsO or PsA and NMRI or NBRI. Nail PD grade did not differ between groups. Type I and IV TS changes were more frequent in PsO; types II and III changes were more frequent in PsA (p < 0.001). NPT was greater in PsA and PsO groups than controls: PsA 0.73 ± 0.14 mm, PsO 0.72 ± 0.15 mm, Controls 0.67 ± 0.10 mm (p = 0.001).

CONCLUSION

Echographic TS characteristics of the nail plate and NPT evaluated by GS are useful and can distinguish PsO and PsA nails from controls. NMRI, NBRI, and US nail microcirculation parameters could not distinguish psoriatic nails.

TRIAL REGISTRATION

72762317.4.0000.5327 (Certificate of Presentation of Ethical Appreciation - CAAE - Plataforma Brasil) Avaiable in  https://plataformabrasil.saude.gov.br/login.jsf .

Dermoscopic features of nail psoriasis: Positive correlation with the severity of psoriasis

Dermoscopy is an efficient and non-invasive technique which has been widely used in the diagnosis of nail disorders including nail psoriasis (NP). Many nail dermoscopic features are considered as clues to NP. The aim of this study was to investigate specific dermoscopic features of fingernail psoriasis and the correlation between the severity of nail lesions or systemic inflammation, and psoriasis severity of skin and nail. This observational study recruited 135 patients with fingernail psoriasis (1186 fingernails) and 30 patients with onychomycosis (80 fingernails). All of the involved fingernails were examined with a handheld dermatoscope. The Nail Psoriasis Severity Index score (NAPSI) score, Psoriasis Area and Severity Index (PASI) score, body surface area (BSA), and detailed history of patients with psoriasis were recorded. Mann-Whitney U-test, χ² -test, Spearman's correlation, and Kruskal-Wallis H-test were used for statistical analysis, and the significance threshold was p < 0.05. The trial registration number was 2020-SR-045. We identified onycholysis as the most common feature (93.3%) of fingernail psoriasis. Red lunula, longitudinal fissures, transverse grooves, nail plate crumbling, trachyonychia, oil-dropping sign, erythematous border of an onycholytic area, subungual hyperkeratosis, and dilated streaky capillaries were relevant to NP severity (p < 0.05). Red lunula, transverse grooves, nail plate crumbling, trachyonychia, oil-dropping sign, erythematous border of an onycholytic area, splinter hemorrhages, and dilated streaky capillaries were relevant to systemic inflammation severity (p < 0.05). The total NAPSI score was positively associated with the PASI score and BSA (p < 0.0001). The thumb had a higher NAPSI score than the other fingers (p < 0.05). In conclusion, dermoscopic features can improve the accuracy of diagnosis of nail psoriasis, and have correlations with psoriasis severity.

A Systematic Review of the Inclusion of Non-Inflammatory Ultrasonographic Enthesopathy Findings in Enthesitis Scoring Indices

Ultrasound has advanced the diagnosis and management of patients with inflammatory rheumatic conditions. It can be used to identify and monitor enthesitis, a cardinal feature of spondyloarthropthies. Several enthesitis scoring systems utilizing ultrasound to determine entheseal involvement have been developed. These scoring systems generally rely on determining the presence or absence of erosions, tendon enlargement, power Doppler signal, or enthesophytes. This systematic review identified ultrasound scoring systems that have been utilized for evaluating enthesitis and what key components derive the score. Review of these scoring systems, however, demonstrated confounding as some of the score components including enthesophytes may be seen in non-inflammatory conditions and some components including erosions can be seen from chronic damage, but not necessarily indicate active inflammatory disease. What is furthermore limiting is that currently there is not an agreed upon term to describe non-inflammatory enthesopathies, further complicating these scoring systems. This review highlights the need for a more comprehensive ultrasound enthesopathy scoring index.

Psoriatic onycho-pachydermo periostitis (POPP): a case report treated successfully with IL-17 blockade and a literature review on characteristics, pathogenesis, and treatment

Psoriatic onycho-pachydermo periostitis (POPP) is characterized by psoriatic onychodystrophy, connective tissue thickening, and periostitis of the distal phalanges (DPs), producing a drumstick-like deformity. Our aim was to present the first case of POPP treated successfully with an IL-17 inhibitor, perform a literature review of its characteristics and treatment, and explore the possible pathogenesis. We conducted a systematic review of previously presented POPP cases. We present a patient with methotrexate (MTX)-resistant treatment POPP, who had significant resolution of symptoms and inflammatory lesions on post-treatment MRI with secukinumab 150 mg. We also identified 31 cases of POPP (27 males; mean age 44.9 years) in the literature review. There was great toe involvement in 24 cases, and distal interphalangeal (DIP) involvement in 14 cases, with frequent radiographically evident damage. Seventeen of 31 patients received systematic treatment other than biologics, mostly MTX, with no satisfactory results. Anti-TNF agents were used successfully in 5 cases, mostly after disease modifying anti-rheumatic drug (DMARD) failure. Imaging studies in nail psoriasis and DIP psoriatic arthritis have shown an anatomical link among the nail, the DP bone, and the DIP joint entheses, suggesting that POPP may be a subtype of nail disease with excessive involvement of DP tissues (nail, soft tissue, enthesis, and bone). IL-17 inhibition could be an alternative therapeutic option in DMARD-resistant cases of POPP. Conventional treatment achieves modest success, but anti-TNF agents appear to be much more effective. Based on imaging studies, POPP may be a particular subtype of nail disease.

Concepts, Role, and Advances on Nail Imaging

This review discusses, from a practical point of view, the most common imaging techniques and their applications in nail pathologies with some technical considerations. There are several imaging techniques for studying the nail, and all of them require proper devices and trained operators. The highest axial resolution and a more extensive range of applications are provided by ultrasound, which currently is the first-choice imaging technique for evaluating nail conditions. A correlation of state-of-the-art clinical and imaging figures supports the review of this topic.

Nail Psoriasis: Diagnosis, Assessment, Treatment Options, and Unmet Clinical Needs

OBJECTIVE

An estimated 40-50% of patients with psoriasis (PsO) have psoriatic nail disease, which is associated with and directly contributes to a greater clinical burden and worse quality of life in these patients. In this review, we examine how recent advances in the use of new diagnostic techniques have led to improved understanding of the link between nail and musculoskeletal manifestations of psoriatic disease (PsD; e.g., enthesitis, arthritis) and we review targeted therapies for nail PsO (NP).

METHODS

We performed a literature search to identify which systemic therapies approved for the treatment of PsO and/or psoriatic arthritis (PsA) have been evaluated for the treatment of NP, either as a primary or secondary outcome. A total of 1546 articles were identified on February18, 2019, and evaluated for relevance.

RESULTS

We included findings from 66 articles on systemic therapies for the treatment of NP in PsD. With several scoring systems available for the evaluation of psoriatic nail disease, including varied subtypes and application of the Nail Psoriasis Area Severity Index, there was a high level of methodological heterogeneity across studies.

CONCLUSION

NP is an important predictor of enthesitis, which is associated with the early stages of PsA; therefore, it is important for rheumatologists and dermatologists to accurately diagnose and treat NP to prevent nail damage and potentially delay the onset and progression of joint disease. Further research is needed to address the lack of both standardized NP scoring systems and well-defined treatment guidelines to improve management of PsD.

Imaging in Psoriatic Arthritis-Insights About Pathogenesis of the Disease

PURPOSE OF REVIEW

Heterogeneity is a hallmark of PsA as musculoskeletal inflammation can affect different tissues including the synovial joint, tendons, entheses, bursa, and bone.

RECENT FINDINGS

Relying on clinical examination for investigating underlying mechanisms in PsA is limited by the inherent inaccuracies of examination of the joints, enthesis, and spine. In addition, unlike synovial-centered diseases, histology is hard to obtain for the entheses and spine, limiting the knowledge for different manifestations of PsA. These limitations prompted the use of imaging modalities to improve our understanding of the underlying mechanisms in PsA. Imaging modalities can identify and quantify the extent of inflammation and damage in the synovial joints, entheses, and tendons which all contribute to the heterogeneity of PsA. This review summarizes the contribution of imaging to the understanding of the underlying mechanisms of different clinical manifestations of PsA.