Ultrasound entheseal abnormalities at the distal interphalangeal joints and clinical nail involvement in patients with psoriasis and psoriatic arthritis, supporting the nail-enthesitis theory

Ultrasound of Nails: Why, How, When

Nail disorders are frequently a challenge to diagnose correctly only based on clinical findings. Moreover, biopsies may leave scars due to damage to the nail matrix. Currently, high-frequency ultrasound (HFUS) with probes >15 MHz is the first-choice imaging technique to study the nail. Compared with other imaging tests such as computed tomography and magnetic resonance imaging, HFUS has the advantage of high-resolution imaging of the nail apparatus without exposure to radiation, contrast media, and the risk of claustrophobia of these other expensive imaging methods. Notably, the axial spatial resolution of HFUS is higher than computed tomography and magnetic resonance imaging; therefore, it can better discriminate the anatomical alterations. Our objective is to review the main applications of HFUS of the nail through literature analysis and illustration of cases of the most frequent pathologies found in our experience, exemplifying why, how, and when HFUS could help diagnose nail diseases.

Ultrasonographic Insights into Peripheral Psoriatic Arthritis: Updates in Diagnosis and Monitoring

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis, characterized by heterogeneous clinical manifestations and variable disease progression. Ultrasonography has emerged as a valuable tool in the diagnosis and monitoring of PsA, providing real-time visualization of joint and soft tissue abnormalities. This review highlights recent advancements in ultrasonographic techniques for the assessment of PsA, including the identification of typical features, the role of power Doppler imaging in detecting active inflammation, and the potential of ultrasound for guiding treatment decisions. Additionally, we discuss the utility of ultrasound in assessing treatment response and monitoring disease progression in patients with PsA, with a focus on novel imaging modalities. By elucidating the evolving role of ultrasonography in PsA management, this article aims to enhance clinicians' understanding of its utility in facilitating early diagnosis, optimizing treatment strategies, and improving patient outcomes.

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.

Systematic study on nail plate assessment: differences in nail plate shape, thickness, power Doppler signal and scanning approach

Ultrasonography (US) of the nail is raising interest in the last years and its feasibility, quickness and amount of descriptive data may provide valuable information. Different authors presented several scanning approaches to nail complex in different pathological conditions, such as psoriasis, but no scanning protocol was ever proposed using healthy subjects as population of reference. The aim of the study was to establish a protocol for the US of nail plate and to assess whether the measurement of the nail plate is influenced by longitudinal vs transverse scan, sex, digit and hand dominance. Using high frequency probe and a Canon Aplio i800 machine, ultrasonographers took scans of nail plates of the hands from healthy subjects. Nail plate shape, thickness and power Doppler signal (PDUS) were evaluated and scans were taken both on longitudinal and transverse axis, at distal, middle and proximal portion of the nail plate or at a fixed angles of - 45°, 0° or + 45°. All the images were then revised and scored using a DICOM software, in order to allow good standards of accuracy and reproducibility. A total of 27 subjects (14 females and 13 males) were assessed. The measures did not result to differ in different portions or angles. Furthermore, no difference appears in sex or dominant vs not dominant hand. A decreasing and significant trend for nail plate thickness was found from the first to the fifth finger. Doppler signal was found in all but one subjects, with a range from almost absent to very evident. No difference was found between groups regarding PDUS. The data provided suggest that a proper scan protocol should include all the nails and evaluation should be done both on longitudinal and transverse axis. Since Doppler signal is highly variable in healthy subjects, its presence should be carefully considered as pathological finding. Observations provided by this study clarify important points of the scanning technique and solve doubts related to which nails should be scanned and where to evaluate quantitative parameters.

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.

Differential Diagnosis of Inflammatory Arthritis from Musculoskeletal Ultrasound View

Diagnostic imaging in rheumatology has evolved over the centuries, and novel imaging modalities, including musculoskeletal ultrasonography (MSUS) and magnetic resonance imaging (MRI), are being widely used in the 21st century. With the increase in availability of molecular target-specific therapies, including biologic agents and Janus kinase (JAK) inhibitors, the therapeutic outcome of inflammatory arthritis has changed, and early and accurate diagnosis of inflammatory rheumatic diseases has become more important. Given this situation, MSUS, which is a portable, convenient, noninvasive, and cost-effective imaging technique, plays an important role in the diagnosis of rheumatic diseases. MSUS can be used to detect subclinical inflammation and to accurately determine the distribution of joint involvement and inflammation sites in each joint. Definitive diagnosis for patients with early arthritis should be made after noting their history and performing clinical examination, laboratory testing, and additional procedures. However, MSUS is an extension of physical examination and it can provide a further opportunity and motivation to consider differential diagnoses rather than a conclusive diagnosis. This review aims to describe the usefulness of MSUS in differential diagnoses of the phenotype of early inflammatory arthritis.

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.

Multimodal imaging of the distal interphalangeal-joint synovio-entheseal complex in psoriatic arthritis (MIDAS): a cross-sectional study on the diagnostic accuracy of different imaging modalities comparing psoriatic arthritis to psoriasis and osteoarthritis

Objective

Can ultrasound (US), MRI and X-ray applied to the distal interphalangeal (DIP)-joint and synovio-entheseal complex (SEC) discriminate between patients with psoriatic arthritis (PsA), skin psoriasis (PsO) and hand osteoarthritis (OA)?

Methods

In this prospective, cross-sectional study, patients with DIP-joint PsA and nail involvement (n=50), PsO with nail involvement (n=12); and OA (n=13); were consecutively recruited. Risk ratios (RR) were calculated for US, MRI and X-ray findings of the DIP-joint and SEC between diagnoses.

Results

New bone formation (NBF) in US and MRI was a hallmark of OA, reducing the risk of having PsA (RR 0.52 (95% CI 0.43 to 0.63) and 0.64 (95% CI 0.56 to 0.74). The OA group was different from PsA and PsO on all MRI and X-ray outcomes reflected in a lower RR of having PsA; RR ranging from 0.20 (95% CI 0.13 to 0.31) for MRI bone marrow oedema (BMO) to 0.85 (95% CI 0.80 to 0.90) in X-ray enthesitis. No outcome in US, MRI or X-ray was significantly associated with a higher risk of PsA versus PsO, although there was a trend to a higher degree of US erosions and NBF in PsA. 82% of PsA and 67% of PsO was treated with disease modifying antirheumatic drugs which commonly reflects the clinical setting.

Conclusion

High grade of US, MRI and X-ray NBF reduce the RR of having PsA compared with OA. In PsA versus PsO patients, there was a trend for US to demonstrate more structural changes in PsA although this did not reach significance.

Nail and enthesis assessment in patients with psoriatic disease by high frequency ultrasonography: findings from a single-centre cross-sectional study

PURPOSE

To characterize nail and enthesis abnormalities using high frequency ultrasound (HFUS) in patients with psoriasis (PSO), psoriatic arthritis (PSA) with PSO, and PSA sine PSO.

MATERIAL AND METHODS

Patients with PSO, PSA with PSO, and PSA sine PSO were evaluated and compared in a cross-sectional single centre study. Nail and enthesis abnormalities were evaluated by HFUS using high frequency probes (27 MHz). After a descriptive assessment, Brown University Nail Enthesis Scale (BUNES) and Madrid Sonography Enthesitis Index (MASEI) were used to assess nail and enthesis, respectively.

RESULTS

Fifty-nine patients were enrolled (19 PSO, 22 PSA with PSO, 18 PSA sine PSO). In patients with PSO and in those with PSA and PSO, HFUS evaluation identified the following nail alterations characterised by thickened matrix, inhomogeneous echogenicity of the nail bed, and increased blood flow by power Doppler. In 38.9% patients with PSA sine PSO, a subclinical nail involvement was described. No difference was observed comparing BUNES values in three groups. In PSA patients with PSO and in those with PSA sine PSO, HFUS assessment of entheses mainly showed a hypoechoic aspect and thickness of the tendon, focal cortical erosion, and ossification. A subclinical enthesis involvement in 47.4% patients with PSO was observed. No difference was reported comparing MASEI values in three groups.

CONCLUSION

Qualitative and quantitative abnormalities of nail and enthesis were demonstrated by HFUS in patients with PSO, PSA with PSO, and PSA sine PSO, suggesting a practical additional tool to be used in clinical settings. Furthermore, HFUS highlighted a subclinical nail involvement in patients with PSA sine PSO and enthesis subclinical alterations in patients with PSO.

The prevalence incidence of psoriatic onychodystrophy and the significance of its symptoms for the diagnosis of psoriatic arthritis

Background. There is a need to assess the diagnostic significance of the symptoms of nail damage, as well as available effective methods for diagnosing psoriatic arthritis in the early stages. Aims. To study of the occurrence of symptoms of psoriatic onychodystrophy in patients with psoriatic arthritis and assessment of the diagnostic significance of the ultrasound method for diagnosing enthesitis as an early symptom of psoriatic arthritis among patients with onychodystrophy and without psoriatic arthritis in case history. Methods. It was a prospective clinical study based on the Clinic of Skin and Venereal Diseases of the Military Medical Academy. We made the clinical assessment of symptoms of onychodystrophy among patients with and without psoriatic arthritis and the evaluation of the diagnostic significance of the ultrasound method for diagnosing psoriatic arthritis under the control of magnetic resonance imaging of the joints. Results. 45 patients with psoriatic arthritis and 134 patients with psoriasis without arthritis were examined. Psoriatic onychodystrophy was significantly more common in the group of patients with psoriatic arthritis (p = 0.028). The most characteristic symptoms of onychodystrophy in patients with psoriatic arthritis are oil spots and symptom combinations: oil spots and subungual hyperkeratosis, onycholysis and subungual hyperkeratosis, pits and longitudinal ridges, oil spots and longitudinal ridges. The ultrasound method for the diagnosis of psoriatic arthritis has shown its high diagnostic significance (Se = 81.8%, Sp = 88.0%). The most characteristic symptoms of arthritis on ultrasound examination are hypoechoic structures of the Achilles tendons and the presence of fluid in the peri- and retro-Achilles bursa. Conclusions. The symptom of oil spots and combinations of oil spots with subungual hyperkeratosis, onycholysis with subungual hyperkeratosis, pits with longitudinal ridges and oil spots with longitudinal ridges can be considered diagnostically significant in the examination of early psoriatic arthritis, and the ultrasound method is highly effective in diagnosing early manifestations of arthritis.

Integrating imaging and biomarker assessment to better define psoriatic arthritis and predict response to biologic therapy

The treatment options for PsA have substantially expanded over the last decade. Approximately 40% of patients will not respond to first-line anti-TNF-α therapies. There is limited data to help clinicians select the most appropriate biologic therapy for PsA patients, including guidance for decisions on biologic therapy switching. In this review we will examine the current understanding of predictors of response to treatment. Imaging technology has evolved to allow us to better study psoriatic disease and define disease activity, including synovitis and enthesitis. Enthesitis is implicated in the pathogenesis, diagnosis and prognosis of PsA. It appears to be a common thread among all of the various PsA clinical presentations. Enthesitis mainly manifests as tenderness, which is difficult to distinguish from FM, chronic pain and mechanically associated enthesopathy, and it might be relevant for understanding the apparent 40% failure of existing therapy. Excess adipose tissue makes if more difficult to detect joint swelling clinically, as many PsA patients have very high BMIs. Integrating imaging and clinical assessment with biomarker analysis could help to deliver stratified medicine in PsA and allow better treatment decision making. This could include which patients require ongoing biologic therapy, which class of biologic therapy that should be, and who alternatively requires management of non-inflammatory disease.

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.

Challenge of Nail Psoriasis: An Update Review

Nail psoriasis is a refractory disease that affects 50-79% skin psoriasis patients and up to 80% of patients with psoriatic arthritis (PsA). The pathogenesis of nail psoriasis is still not fully illuminated, although some peculiar inflammatory cytokines and chemokines seems to be the same as described in psoriatic skin lesions. Psoriatic nail involving matrix can cause pitting, leukonychia, red spots in lunula, and nail plate crumbling, while nail bed involvement can result in onycholysis, oil-drop discoloration, nail bed hyperkeratosis, and splinter hemorrhages. The common assessment methods of evaluating nail psoriasis includes Nail Psoriasis Severity Index (NAPSI), Nail Assessment in Psoriasis and Psoriatic Arthritis (NAPPA), Nail Psoriasis Quality of life 10 (NPQ10), and so on. Treatment of nail psoriasis should be individualized according to the number of involving nail, the affected site of nail and presence of skin and/or joint involvement. Generally, topical therapies are used for mild nail psoriasis, while biologic agents such as etanercept are considered for severe nail disease and refractory nail psoriasis. Even though the current literature has shown some support for the pathogenesis, clinical presentation, or therapies of nail psoriasis, systemic review of this multifaceted disease is still rare to date. We elaborate recent developments in nail psoriasis epidemiology, pathogenesis, anatomy, clinical manifestation, diagnosis, differential diagnosis, and therapies to raise better awareness of the complexity of nail psoriasis and the need for early diagnosis or intervention.

Treating the skin with biologics in patients with psoriasis decreases the incidence of psoriatic arthritis

OBJECTIVES

To compare the incidence of psoriatic arthritis (PsA) in patients with psoriasis (PsO) according to different treatments for their skin: topics/no treatment, conventional disease-modifying antirheumatic drugs (DMARDs) (cDMARDs) or biological DMARDs (bDMARDs).

METHODS

Patients with PsO without PsA followed at a university hospital were included in this retrospective cohort study. Patients were classified according to their treatment in topics (topics, phototherapy or no treatment), cDMARDs (methotrexate and cyclosporine) and bDMARDs (tumour necrosis factor inhibitors (TNFi), interleukin 17 inhibitors (IL-17i) and IL-12-23i ((interleukin (IL) 12/IL-23 inhibitor))) groups. Incident cases of PsA were attributed to one treatment if developed during the administration of that treatment. A Cox proportional hazards model was used to evaluate the adjusted risk of PsA development by treatment group.

RESULTS

1719 patients with PsO contributed a total of 14 721 patient/years (py). 1387 (81%) patients were in the topics, 229 (13%) in cDMARDs and 103 (6%) in the bDMARDs group. During follow-up, 239 patients (14%) developed PsA (231 under topics, six under cDMARDs and two under bDMARDs). Global incidence was 1.6 per 100 py. The risk of developing PsA in patients with PsO treated with bDMARDs was significantly lower (incidence rate ratio (IRR)=0.26; 95% CI 0.03 to 0.94; p=0.0111), compared with topics, but not compared with cDMARDs (IRR=0.35; 95% CI 0.035 to 1.96; p=0.1007). Adjusted Cox proportional hazards regression analysis showed that male sex, nail involvement and higher body max index were associated with increased risk of developing PsA, while biologics use was protective (HR: 0.19; 95% CI 0.05 to 0.81).

CONCLUSION

Treatment with biologics in patients with PsO reduced the risk of PsA development.

Ultrasound Evaluation of the Effectiveness of the Use of Acitretin in the Treatment of Nail Psoriasis

The study aimed to evaluate the effect of retinoid treatment on the morphological changes in the nail apparatus in patients with nail psoriasis. Material and methods: 41 patients aged 32 to 64 with nail psoriasis, without clinical signs of psoriatic arthritis, started on acitretin 0.6 to 0.8 mg kg b.w./d, for six months and 28 people in the control group were included in the study. Both groups had ultrasound examination of fingernails and digital extensor tendon in the distal interphalangeal joints. In psoriatic patients, US examination was conducted before starting the treatment and after six months. A total of 685 nails were examined. Results: After six months of treatment, there was a reduction in the thickness of the nail bed and nail matrix (p = 0.046 and p = 0.031, respectively). The thickness of the nail plates decreased, although it was statistically insignificant (p = 0.059) and it was higher than in the control group (p = 0.034). The reduced severity of clinical nail changes after six months of retinoid treatment did not correlate with the reduction in extensor tendon thickness in any group of patients. Conclusions: In patients with nail psoriasis, acitretin treatment resulted in a rapid decrease in the thickness of the nail bed and matrix, but it did not affect the thickness of the nail plate after six months. There was no effect of acitretin on the digital extensor tendon thickness or the increased blood supply to the tendon area. The results of the study may indicate the usefulness of ultrasound nail examinations in patients with nail psoriasis not only to assess the advancement of morphological changes and response to treatment, but also to choose the potential treatment.

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.

Dermatologists' Role in the Early Diagnosis of Psoriatic Arthritis: Expert Recommendations

Psoriatic arthritis is a common type of inflammatory arthritis found in up to 40% of patients with psoriasis. Because skin involvement usually precedes joint involvement, dermatologists play a key role in early detection. Early diagnosis is important for reducing the risk of irreversible structural damage, attenuating the deterioration of physical function, and improving patients' quality of life. This consensus statement was drafted by a group of 9 dermatologists and 1 rheumatologist to provide simple recommendations to help dermatologists screen for psoriatic arthritis in patients with psoriasis. The experts offer consensus-based guidelines that draw on a review of available scientific evidence and on experience acquired in routine clinical practice.

Histological Evaluation of the Relationships Between Distal Interphalangeal Psoriatic Arthritis and Nail Psoriasis: Correlations With Anatomical Studies of the Normal Nail Unit and the Main Radiological Data Concerning Distal Interphalangeal Psoriatic Arthritis

To determine whether distal interphalangeal joint psoriatic arthritis (DIP PsA) and nail psoriasis are anatomically linked, we studied 2 fingers taken from a cadaver presenting a typical cutaneous and nail psoriasis in the setting of a dactylitis limited to the fourth toe. This comprehensive study of the inflammatory pattern of DIP PsA is discussed in the context of the controversial theory of the nail as a musculoskeletal appendage. Both the extensor and flexor entheses were focally and quite markedly infiltrated by lymphocytes and showed variable fibrosis and neovascularization. In addition, some clusters of giant cells were seen. Synovial perivascular inflammation was focally relatively dense. Discrete periostitis and bone inflammation of the intertrabecular spaces were seen, maximally at the insertion of the extensor and flexor tendons. The retained superficial fibrocartilaginous and tendinous cuff separated the inflamed extensor enthesis from the surrounding connective tissues. The thick proximal periosteum constituted a barrier between the inflamed bone and the matrical hypoderm. The lateral sections showed inflammation at 3 levels as follows: the enthesis of the interosseous ligament and collateral ligament, periosteum, and nail epithelium. In the 3 specimens, the inflammatory foci involving entheses and nails were prominent and never contiguous. This suggests that DIP PsA is not merely an extensor enthesitis and that the nail unit remains a microanatomical structure independent from the extensor enthesis, even with severe DIP PsA.

The importance of ultrasound in identifying and differentiating patients with early inflammatory arthritis: a narrative review

Early differentiation between different types of inflammatory arthritis and subsequent initiation of modern treatments can improve patient outcomes by reducing disease activity and preventing joint damage. Routine clinical evaluation, laboratory testing, and radiographs are typically sufficient for differentiating between inflammatory and predominantly degenerative arthritis (e.g., osteoarthritis). However, in some patients with inflammatory arthritis, these techniques fail to accurately identify the type of early-stage disease. Further evaluation by ultrasound imaging can delineate the inflammatory arthritis phenotype present. Ultrasound is a noninvasive, cost-effective method that enables the evaluation of several joints at the same time, including functional assessments. Further, ultrasound can visualize pathophysiological changes such as synovitis, tenosynovitis, enthesitis, bone erosions, and crystal deposits at a subclinical level, which makes it an effective technique to identify and differentiate most common types of inflammatory arthritis. Limitations associated with ultrasound imaging should be considered for its use in the differentiation and diagnosis of inflammatory arthritides.

Enthesitis and its relationship with disease activity, functional status, and quality of life in psoriatic arthritis: a multi-center study

Psoriatic arthritis (PsA) is an inflammatory arthritis with distinct phenotypic subtypes. Enthesitis is assigned as a hallmark of the disease, given its significant relations to disease activity and quality of life. Our objective is to evaluate the prevalence of enthesitis and its association with some clinical parameters, particularly quality of life, using data from a national registry. Patients with PsA meeting ClASsification criteria for Psoriatic Arthritis (CASPAR) were enrolled by means of a multi-centre Turkish League Against Rheumatism (TLAR) Network Project. The following information was recorded in web-based case report forms: demographic, clinical and radiographic data; physical examination findings, including tender and swollen joint counts (TJC and SJC); nail and skin involvement; Disease Activity Score-28 for Rheumatoid Arthritis with Erythrocyte Sedimentation Rate (DAS 28-ESR); Bath Ankylosing Spondylitis Disease Activity Index (BASDAI); Maastricht Ankylosing Spondylitis Enthesitis Score (MASES); Psoriasis Area Severity Index (PASI); Bath Ankylosing Spondylitis Radiology Index for the spine (BASRI-s); Health Assessment Questionnaire (HAQ); Bath Ankylosing Spondylitis Functional Index (BASFI); Health Assessment Questionnaire for the spondyloarthropathies (HAQ-s); Psoriatic arthritis quality of Life scale (PsAQoL); Short Form 36 (SF-36); Hospital Anxiety Depression Scale (HADS); Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F); and Fibromyalgia Rapid Screening Tool (FiRST) scores. The patients were divided into two groups, namely with and without enthesitis, based on the triple Likert-type physician-reported statement of 'active enthesitis', 'history of enthesitis' or 'none' in the case report forms. Patients with active enthesitis were compared to others in terms of these clinical parameters. A total of 1130 patients were enrolled in this observational study. Of these patients, 251 (22.2%) had active enthesitis according to the clinical assessment. TJC, HAQ-s, BASDAI, FiRST and PsAQoL were significantly higher whereas the SF-36 scores were lower in patients with enthesitis (p < 0.05). Chronic back pain, dactylitis, and tenosynovitis were more frequent in the enthesopathy group (59.4%/39%, 13.1%/6.5% and 24.7%/3.4%, respectively). Significant positive correlations between the MASES score and the TJC, HAQ, DAS 28-ESR, BASDAI, FiRST and PsAQoL scores, and a negative correlation with the SF-36 score were found. When linear regression analysis was performed, the SF-36 MCS and PCS scores decreased by - 9.740 and - 11.795 units, and the FiRST scores increased by 1.223 units in patients with enthesitis. Enthesitis is an important involvement of PsA with significant relations to quality of life determined with PsAQoL and SF-36 scores. Our study found higher frequency of dactylitis and chronic back pain, and worse quality of life determined with SF-36 and PsAQoL scores in patients with enthesitis.

Nail ultrasonography for psoriatic arthritis and psoriasis patients: a systematic literature review

To systematically review the role of ultrasound (US) in the assessment of the joint-enthesial-nail apparatus in patients with psoriatic arthritis (PsA) or psoriasis (PSO) in terms of prevalence, diagnosis, prognosis, monitoring and treatment. A systematic literature review was conducted through medical databases (PubMed, Embase) and the grey literature up to February 2018. The main areas of application of nail US were first identified, allowing the development of research questions, which were rephrased following the PICOs methodology to develop inclusion criteria. Of the 585 studies produced by PubMed and Embase searches, 17 studies met the criteria for inclusion. Five additional studies were included: 1 from the hand search and 4 from the 2016-2017 ACR and EULAR congresses. The prevalence of nail plate changes varied from < 10 to 97%, for power Doppler signal from 20-30 to 96% and distal interphalangeal joint (DIJ) involvement from 8.9 to 100%. The performance of US nail/DIJ abnormalities in the diagnosis of PsA and PSO elementary lesions was analysed by five studies, with a wide heterogeneity. Reproducibility and reliability of US nil/DIJ were assessed by interclass correlation coefficient or Cohen's k and their values ranged from 0.6 to 0.9. The value of US nail/DIJ in the monitoring of the lesions was analysed only by a single study. The analysis revealed applications for US nail/DIJ in PsA and PSO and highlights limitations. Validation is strongly needed to demonstrate its appropriateness in the clinical practice and to define its diagnostic and prognostic role.

Distal interphalangeal joint extensor tendon enthesopathy in patients with nail psoriasis

The aim of the study was an ultrasound assessment of distal interphalangeal (DIP) joint enthesopathy in patients with nail psoriasis. Altogether, 72 patients with nail psoriasis (41 with psoriasis and 31 with psoriatic arthritis) and 30 people in the control group participated in the study. In total, 1014 nails were examined. The thickness of DIP digital extensor tendons in the groups of patients with psoriasis (Ps) and psoriatic arthritis (PsA) was correlated with the nail bed thickness (r = 0.316, p = 0.027 vs. r = 0.402, p = 0.031, respectively) and with the thickness of the nail matrix in patients with psoriasis (r = 0.421, p = 0.012). The linear regression model showed the tendon thickness in Ps patients to be affected by the nail bed thickness, duration of psoriasis and the thickness of the nail matrix, whereas in PsA patients it was found to be significantly affected by duration of psoriasis and of arthritis, the nail bed thickness, CRP concentration and the swollen joint count. Our findings may indicate the role of the nail-tendon apparatus changes in the PsA development and they emphasise the justifiability of US examinations in patients with psoriasis direct assessment of morphological changes in nails as potential predictors of PsA development.

Effect of Methotrexate in the Treatment of Distal Interphalangeal Joint Extensor Tendon Enthesopathy in Patients with Nail Psoriasis

To assess the effect of methotrexate on the development of distal interphalangeal joint extensor tendon enthesopathy in psoriasis, thirty-two people aged 34 to 57 years with nail psoriasis and distal interphalangeal joint extensor tendon enthesopathy (19 patients with Ps (psoriasis) and 13 with PsA (psoriatic arthritis) were started on methotrexate at 15 to 25 mg/week and the treatment was continued for 6 months). A total of 319 nails were examined. After six months of treatment, the thicknesses of the nail plate, nail bed and nail matrix were found to decrease in both groups of patients. Methotrexate treatment resulted in a decrease in the joint extensor tendon thickness only in patients with Ps (0.94 ± 0.05 vs. 0.96 ± 0.04, p < 0.001), where the tendon thickness after treatment correlated with the matrix thickness (r = 0.337, p = 0.018) and with the bed thickness (r = 0.299, p = 0.039). Methotrexate treatment resulted in a decrease in the extensor tendon thickness only in patients with Ps but not in PsA. The findings of this study may suggest the effectiveness of systemic treatment of nail psoriasis in patients without arthritis and the use of US nail examinations in Ps and PsA patients in morphological change assessment and response to treatment.

Enthesitis and Dactylitis in Psoriatic Disease: A Guide for Dermatologists

Psoriatic arthritis (PsA) is an inflammatory arthritis that is estimated to affect approximately 30% of patients with psoriasis. Enthesitis and dactylitis, two hallmarks of PsA, are associated with radiographic peripheral/axial joint damage and severe disease. Clinical symptoms of enthesitis include tenderness, soreness, and pain at entheses on palpation, whereas dactylitis is recognized by swelling of an entire digit that is different from adjacent digits. Both ultrasound and magnetic resonance imaging can be used to diagnose enthesitis and dactylitis, especially in patients in whom symptoms may be difficult to discern. Delayed treatment of PsA can result in irreversible joint damage and reduced quality of life. Thus, it is recommended that dermatologists monitor patients with psoriasis for these two early and important manifestations of PsA.

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.

Ultrasound Assessment of Changes in Nails in Psoriasis and Psoriatic Arthritis

Aim of the Study

The aim of the study was to conduct an ultrasound (US) assessment of changes in fingernails in psoriatic patients with nail involvement.

Material

A total of 69 patients with psoriatic changes in nails participated in the study, including 38 patients with psoriasis (Ps) and 31 with psoriatic arthritis (PsA) and 30 people in the control group. A total of 988 nails were examined.

Results

The thickness of the nail plate, nail bed, and matrix as shown in an ultrasound examination increased with the mNAPSI index (r=0.328, p=0.021; r=0.219, p=0.036; and r=0.422, p=0.011, respectively). The thickness of nail plate, bed, and matrix in patients with onycholysis and hyperkeratosis-type changes (concomitant or present separately) was significantly greater than when only pitting-type changes occurred (p=0.007, p=0.035, and p=0.023, respectively). An examination of nails with only pitting-type changes showed an increase in the matrix thickness compared to the control group (p=0.018). The focal hyperechoic involvement of the dorsal plate (80%) was the change most often observed in an US examination in Ps patients, whereas loosening of the borders of the ventral plate was most often observed in PsA patients. The thickness of nail bed in PsA patients increased with the duration of arthritis (r=0.399, p=0.022) and was correlated with the number of swollen digits (r=0.278, p=0.041).

Conclusions

The findings of this study may indicate an association of an inflammation in the nail bed with PsA development. Apart from a direct assessment of the described morphological changes of nails, a US examination could prove useful in an assessment of intensity of a local inflammation as a prognostic factor for PsA development.

Psoriatic arthritis and the dermatologist: An approach to screening and clinical evaluation

Psoriatic arthritis is a common form of inflammatory arthritis that frequently accompanies psoriasis of the skin-up to 30% of patients with psoriasis are affected. Recognition of the clinical features of psoriatic arthritis is critical, as delayed detection and untreated disease may result in irreparable joint injury, impaired physical function, and a significantly reduced quality of life. Recent epidemiologic studies have also supported that psoriatic arthritis is associated with cardiometabolic and cerebrovascular comorbidities, including coronary heart disease, diabetes mellitus, hypertension, dyslipidemia, and cerebrovascular accidents, further highlighting the importance of identifying affected patients. Dermatologists are poised for the early detection of psoriatic arthritis, as psoriasis predates its development in as many as 80% of patients. In an effort to further acquaint dermatologists and other clinicians with psoriatic arthritis, this review provides a detailed overview, emphasizing its salient clinical features, and discusses classification criteria, validated screening tools, and simple musculoskeletal examination maneuvers that may facilitate earlier detection and treatment of the disorder.

Ultrasound as a useful tool to integrate the clinical assessment of nail involvement in psoriatic arthritis

Developing the skills to adequately assess nail lesions in psoriasis is mandatory for correct interpretation of the pathological features and to provide correct management of psoriatic patients. Although clinical assessment is part of an accurate diagnosis of nail psoriasis, recent advances in the field of imaging are generating growing interest among clinicians exploring its potential role for the assessment of nail psoriasis. We would like to address the attention to ultrasound (US), which is having an impact in different clinical scenarios such as diagnosis, prognosis, and treatment monitoring of nail involvement in psoriatic disease

Psoriatic arthritis: new evidence for old concepts

PURPOSE OF REVIEW

The review gives an updated overview of some of the new concepts in the management of psoriatic arthritis (PsA): early diagnosis, remission as an objective, treat-to-target, and treatment guidelines.

RECENT FINDINGS

Early diagnosis, targeting remission as part of a treatment strategy, and new guidelines providing evidence-based support to these concepts are main topics in recent publications.

SUMMARY

Dermatologists and rheumatologists should work together to reduce the number of patients remaining undiagnosed, and the time to do so.Remission definition in PsA is still controversial. There is good evidence and convincing arguments for both multidimensional measures, such as minimal disease activity, or unidimensional ones, as disease activity index for PsA. New data on the analysis of tight control of inflammation in early PsA trial showed that the strategy might not be cost-effective on the short term, and that oligoarthritis is less benefited.The new European League Against Rheumatism and Group for Research and Assessment of Psoriasis and PsA recommendations exhibit differences. Methotrexate and tumor necrosis factor inhibitors are favored in European League Against Rheumatism guidelines, whereas other conventional synthetic disease-modifying antirheumatic drugs and biologics are equally positioned in Group for Research and Assessment of Psoriasis and PsA recommendations.