High-frequency sonography in the evaluation of psoriasis: nail and skin involvement

Ultrasound nail assessment in patients with psoriasic arthritis: is there an association of findings with clinical scores?

BACKGROUND

Psoriatic arthritis can involve several domains. Due to its multifaceted nature and its frequent comorbidities such as depression, obesity, osteoarthritis and fibromyalgia, it is difficult to monitor these patients because the clinical scores involve subjective data. High-resolution ultrasound probes allowed the evaluation of more superficial structures, such as the nails and their synovio-entheseal framework, in close relationship with the enthesis of the distal extensor digitorum tendon. Nail ultrasound studies vary in terms of the parameters and fingers studied and in their findings.

OBJECTIVES

To describe the most significant sonographic nail changes and the most affected fingers in psoriatic arthritis and to verify the association of nail ultrasound findings with clinical scores (nail psoriasis severity index (NAPSI), ankylosing spondylitis disease activity score with C-reactive protein (ASDAS-CRP), minimal disease activity (MDA), disease activity index for psoriatic arthritis (DAPSA)).

METHODS

This was a cross-sectional study with 52 patients with psoriatic arthritis at the Hospital de Clínicas do Paraná and 50 controls. A total of 1016 nails were analyzed (517 from patients with psoriatic arthritis and 499 from controls). Ultrasonography of the nails of the 10 fingers was performed to assess the trilaminar appearance, measure the distance from the nail bed, identify synovitis of the distal interphalangeal joints and the presence of a power Doppler signal from the nail matrix/nail bed. The captured images were independently evaluated by a rheumatologist with expertise in musculoskeletal ultrasound. Data analysis was performed using IBM SPSS Statistics v.28.0.0 software, and the association of nail plate changes, nail bed distance and power Doppler signal with the NAPSI, DAPSA, MDA and ASDAS-PCR were calculated. Spearman correlation coefficients were estimated to analyze the correlations between pairs of quantitative variables. Student's t test and the Mann‒Whitney U test were used to compare quantitative variables, and Fisher's exact test was used to compare categorical variables between patients and controls. The nonparametric Mann‒Whitney U and Kruskal‒Wallis tests were used to compare groups according to the MDA or DAPSA classification.

RESULTS

The Doppler signal of the nail matrix and nail bed was more frequently identified in patients (44.2%) than in controls (6%), and the difference in the mean power Doppler signal between the two groups was significant (p < 0.001). Changes in the nail plate were more common in the right thumb (44.2%), left thumb (36.5%) and second finger on the right hand (32.7%). The number of fingers with nail plate changes, enthesitis, paratendinitis, grayscale synovitis and DIP involvement in the distal interphalangeal joints was higher among patients with psoriatic arthritis (p < 0.001). There were found some correlations between US findings and clinical scores: ultrasound nail involvement and the NAPSI score (p = 0.034), the number of fingers and mean change in the nail plate and the ASDAS-CRP (p = 0.030). DAPSA (remission/low activity versus moderate/high activity) was associated to the mean change in the nail plate (p < 0.013).

CONCLUSIONS

Nail ultrasound has the potential to assist in the capturing of the actual disease activity status in patients with psoriatic arthritis.

Seeing beyond skin deep: High-resolution ultrasound in dermatology-A comprehensive review and future prospects

High-resolution ultrasound (HRUS), operating at frequencies of 20-25 MHz, is a non-invasive imaging tool that offers dermatologists the ability to visualize structures beneath the skin surface. The objective of this review is to present a comprehensive overview of HRUS applications, emphasising its utility in diagnosing, characterising and managing various dermatological conditions. We undertook a comprehensive literature review on the dermatological application of HRUS across Medline, Embase and Cochrane Library databases, while also incorporating our own clinical experience of over 16 years with the tool. In normal skin, the epidermis and dermis are hyperechoic, and the subcutaneous layer is hypoechoic. Basal cell carcinomas appear hypoechoic with irregular margins, while the presence of hyperechoic inclusion bodies suggests aggressive pathology. Squamous cell carcinomas pose challenges due to acoustic shadow artefacts from the thickened stratum corneum. Melanomas are homogenous hypoechoic lesions, with HRUS used to accurately predict Breslow thickness. HRUS provides dermatologists with a valuable adjunct to traditional clinical examination. Future advancement in image resolution and the standardisation of diagnostic parameters may further expand its utility.

Role of Color Doppler Ultrasound in Cutaneous Inflammatory Conditions

Inflammatory cutaneous diseases can be challenging to diagnose and manage. Nowadays, the anatomical information provided by ultrasound is critical for detecting subclinical alterations and assessing the severity and activity of these conditions. Many of these entities can be clinically observed in dermatology and other specialties, such as rheumatology, plastic surgery, ophthalmology, and otolaryngology, among others. We review the ultrasonographic patterns of the most common inflammatory cutaneous conditions. In several cases, such as hidradenitis suppurativa, acne, and morphea, there are ultrasonographic staging systems of severity or activity that are pivotal in the management of these diseases. The early ultrasonographic diagnosis of these entities implies a proper management of the patients and, therefore, improve their quality of life. Thus, knowledge of the current use of ultrasound in this field seems essential.

How to Start on Dermatologic Ultrasound: Basic Anatomical Concepts, Guidelines, Technical Considerations, and Best Tips

Dermatologic ultrasound has grown exponentially during the last decades and has passed from the experimental phase to the routine daily practice in multiple countries. The performance of this imaging technique requires color Doppler ultrasound devices working with high-frequency probes, a trained operator on imaging and dermatologic conditions, and the performance of standardized protocols for obtaining the anatomical data properly. In this review, we analyze the ultrasonographic anatomy of the skin, hair, and nails, the technical requirements and considerations, the guidelines, and the recommended protocols, and provide the best tips for practicing this type of examination confidently.

Imaging Approach in the Diagnostics and Evaluation of the Psoriasis Plaque: A Preliminary Study and Literature Review

(1) Background: the aim of the study was to demonstrate its usefulness in the field of imaging evaluation of plaque morphology in psoriasis vulgaris, with an emphasis on the use of confocal microscopy and other advanced skin-imaging techniques. (2) Methods: we conducted a prospective study over two years (July 2022-April 2024), on patients diagnosed with moderate or severe psoriasis vulgaris, treated in the dermatology department of our institution. We selected 30 patients, of whom 15 became eligible according to the inclusion and the exclusion criteria. A total of 60 psoriasis plaques were analyzed by dermatoscopy using a Delta 30 dermatoscope and Vidix 4.0 videodermoscope (VD), by cutaneous ultrasound (US) using a high-resolution 20 MHz linear probe, and by confocal microscopy, along with histopathological analysis. (3) Results: the study included fifteen patients with vulgar psoriasis, diagnosed histopathologically, of whom six were women and nine were men, with an average age of 55. Between two and six plaques per patient were selected and a total of sixty psoriasis plaques were analyzed by non-invasive imaging techniques. Twelve lesions were analyzed with ex vivo fluorescence confocal microscopy (FCM), compared to histology. US showed that the hyperechoic band and the lack of damage to the subcutaneous tissue were the most common criteria. The epidermis and dermis were found to be thicker in the area of psoriasis plaques compared to healthy skin. Dermatoscopy showed that the specific aspect of psoriasis plaques localized on the limbs and trunk was a lesion with an erythematous background, with dotted vessels with regular distribution on the surface and covered by white scales with diffuse distribution. The presence of bushy vessels with medium condensation was the most frequently identified pattern on VD. Good correlations were identified between the histological criteria and those obtained through confocal microscopy. (4) Conclusions: the assessment and monitoring of patients with psoriasis vulgaris can be conducted in a more complete and all-encompassing manner by incorporating dermatoscopy, ultrasonography, and confocal microscopy in clinical practice.

Ultrasonographic and power doppler parameters of nails fail to differentiate between onychodystrophy in patients with psoriasis vulgaris or psoriatic arthritis

BACKGROUND

Nail involvement is frequent in patients with psoriasis (Pso) and psoriatic arthritis (PsA) and there is a relationship between nail involvement and inflammation of the enthesis. The main objective of the present study is to describe the ultrasound findings and clinical characteristics of nails from patients with psoriasis and psoriatic arthritis with and without nail dystrophy.

METHODS

A cross-sectional study including consecutive patients with PsO and PsA was carried out. The study patients were divided into 4 groups, totaling 120 participants. Group 1: patients with psoriasis vulgaris and clinically normal nails; Group 2: patients with psoriasis vulgaris and onychodystrophy; Group 3: patients with psoriatic arthritis and clinically normal nails; Group 4: patients with psoriatic arthritis and onychodystrophy; All patients were submitted to dermatological and rheumatological clinical analysis. Ultrasound examinations was performed by a single examiner, blinded to all clinical data, with ultrasound high resolution, in B-mode or gray-scale (GS), Power Doppler (PD) and Spectral Doppler.

RESULTS

A significant difference was found between the groups regarding the variable Psoriasis Area and Severity Index (PASI) (p = 0.008) and body surface area (BSA) (p = 0.005), with patients with psoriatic arthritis having lower PASI and BSA compared to patients with only cutaneous psoriasis. A positive relationship was found with the average ultrasound thickness of the nail bed and the Nail Psoriasis Severity Index (NAPSI) in correlation analysis (rho = 0.344). When we grouped patients with psoriasis and psoriatic arthritis, there was no significant difference between the cutaneous psoriasis groups and the psoriatic arthritis groups in terms of nail plate GS (p = 0.442), nail bed PD (p = 0.124).

CONCLUSION

Greater nail bed thickness indicates early psoriatic nail disease, as confirmed in our study correlating NAPSI with nail bed thickness. Ultrasonography is a low-cost exam, promising in the evaluation, showing that the ultrasound grayscale is consistent with those who have dystrophic nails, but it can't distinguish psoriasis from psoriatic arthritis, even in those with nail dystrophy.

Ultrasound Features of Nail Lichen Planus

OBJECTIVES

To describe the ultrasonographic features of nail lichen planus (NLP), which, so far, have not been reported in the literature.

METHODS

A retrospective single-center study of NLP patients' color Doppler ultrasound examinations was performed between March 2014 and January 2023. Inclusion criteria were patients ≥15 years with a confirmed clinical diagnosis of NLP in sequential order. Exclusion criteria included concomitant systemic or local cutaneous or nail diseases and systemic or local nail treatments before the ultrasound examination. The ultrasound protocol included the examination of all fingernails or toenails following the reported protocol for dermatologic ultrasound examinations at high and ultra-high frequencies. Patient demographics and ultrasound features of the nail bed, periungual region, nail plate, and regional vascularity were registered and analyzed statistically.

RESULTS

A total of 36 patients met the criteria. All cases presented thickened and decreased echogenicity of the nail bed. A hypoechoic halo surrounding the origin of the nail plate was present in 78% of cases. Exactly 58% of patients presented decreased echogenicity of the proximal periungual dermis, and 86% showed thickening of the periungual dermis. Hypervascularity of the nail bed was seen in 94% of cases. The mean maximum thickness of vessels, the peak systolic velocity of the arterial vessels, and other blood flow findings are provided.

CONCLUSION

Ultrasonography can support the diagnosis of NLP, which benefits the non-invasive discrimination of nail conditions and can avoid the potential permanent scars derived from nail biopsies. Furthermore, ultrasound may be a powerful tool to monitor this disease's treatment.

Inflammation and Psoriasis: A Comprehensive Review

Psoriasis is an immune-mediated disease with a strong genetic component that brings many challenges to sick individuals, such as chronic illness, and which has multiple associated comorbidities like cardiovascular disease, metabolic syndrome, inflammatory bowel disease, and psychological disorders. Understanding the interplay between the innate and adaptative immune system has led to the discovery of specific cytokine circuits (Tumor Necrosis Factor-alpha (TNF-α), IL-23, IL-17), which has allowed scientists to discover new biomarkers that can be used as predictors of treatment response and pave the way for personalized treatments. In this review, we describe the footprint psoriasis leaves on the skin and beyond, key pathophysiological mechanisms, current available therapeutic options, and drawbacks faced by existing therapies, and we anticipate potential future perspectives that may improve the quality of life of affected individuals.

Ultra-High Frequency UltraSound (UHFUS) Assessment of Barrier Function in Moderate-to-Severe Atopic Dermatitis during Dupilumab Treatment

Atopic dermatitis (AD) is a chronic multifactorial inflammatory disease characterized by intense itching and inflammatory eczematous lesions. Biological disease-modifying drugs, such as dupilumab are recommended for patients with moderate-to-severe AD, refractory to systemic immunosuppressive therapies. Disease monitoring is performed by clinical scores. Since 1970, however, the use of ultrasound and particularly high-frequency ultrasound (HFUS), has identified alterations in dermal echogenicity, called the subepidermal low-echogenic band (SLEB), that correlates with disease severity and response to treatment. We enrolled 18 patients with moderate-to-severe AD, divided into two groups: twelve patients in the dupilumab treatment (Group A) and six patients in standard treatment, from February 2019 to November 2019. We performed ultra-high frequency ultrasound (UHFUS) evaluation of lesional and non-lesional skin, focusing on SLEB average thicknesses measurement, epidermal thickness, and vascular signal in correlation with objective disease scores (EASI, IGA), patient's reported scores (Sleep Quality NRS and Itch NRS), and TEWL and corneometry at baseline (T0), after 1 month (T1) and 2 months (T2). The SLEB average thickness measurement, vascular signal, and epidermal thickness showed a statistically significant reduction in lesional skin of the biological treatment group and no significant reduction in non-lesional skin in both groups. In the lesional skin of the standard treatment group, only epidermal thickness showed a statistically significant reduction. Our study demonstrates that SLEB measurement, vascular signals, and epidermal thickness could be used as objective parameters in monitoring the AD treatment response, while the presence of SLEB in non-lesional skin could be used as a marker of subclinical inflammation and could predict development of clinical lesions, suggesting a pro-active therapy. Further follow-up and research are needed to clarify the association of SLEB decrease/disappearance with a reduction of flares/prolongment of the disease remission time.

Clinical, dermoscopic, and ultrasonic monitoring of the response to biologic treatment in patients with moderate-to-severe plaque psoriasis

Background

Assessment of therapeutic response of psoriasis has relied traditionally on clinical observation, and effective non-invasive tools are desirable.

Objectives

To investigate the value of dermoscopy and high-frequency ultrasound (HFUS) in the monitoring of psoriatic lesions treated with biologics.

Methods

Patients with moderate-to-severe plaque psoriasis treated with biologics were evaluated by clinical, dermoscopic, and ultrasonic scores at weeks 0, 4, 8, and 12. Clinical scores, including Psoriasis Area Severity Index (PASI) and target lesion score (TLS), were evaluated at representative lesions. Dermoscopy was performed to assess the red background, vessels, and scales on a 4-point scale as well as the presence of hyperpigmentation, hemorrhagic spots, and linear vessels. HFUS was performed to measure the thicknesses of the superficial hyperechoic band and subepidermal hypoechoic band (SLEB). The correlation between clinical, dermoscopic, and ultrasonic evaluation was also analyzed.

Results

In total, 24 patients were analyzed and achieved 85.3 and 87.5% reduction of PASI and TLS, respectively, after 12 weeks of treatment. The red background, vessels, and scales scores under dermoscopy were reduced by 78.5, 84.1, and 86.5%, respectively. Some patients developed hyperpigmentation and linear vessels after treatment. Hemorrhagic dots slowly subside over the therapeutic course. Ultrasonic scores were significantly improved with an average reduction of 53.9% in superficial hyperechoic band thickness and 89.9% in SLEB thickness. TLS in the clinical variables, scales in dermoscopic variables, and SLEB in ultrasonic variables decreased the most significantly in the early stage of treatment (week 4) with 55.4, 57.7, and 59.1% (P > 0.05), respectively. Most of the variables, including the red background, vessels, scales, and SLEB thickness, were strongly correlated with TLS. High correlations were also found between the SLEB thickness and the red background or vessels scores, and between the superficial hyperechoic band thickness and the scales scores.

Conclusion

Both dermoscopy and HFUS were useful in the therapeutic monitoring of moderate-to-severe plaque psoriasis.

Key Points to Select a Device for Dermatologic Ultrasound

What points to consider when selecting a device for practicing dermatologic ultrasound is an excellent question. After we met the requisites published in the guidelines for practicing dermatologic ultrasound, it is necessary to consider the main objective of the use because it is not the same to be focused mostly on the avoidance of the puncture of important facial vessels such as the case of injectors of cosmetic fillers in comparison to the use of operators that need to deal with the diagnosis and monitoring of a wide range of dermatologic pathologies. Currently, a broad variety of ultrasound devices meets the minimum requirements for practicing these examinations in the market. Thus, small, portable, and high-end devices may present advantages and limitations that must be balanced according to the primary purposes and the budget. Moreover, the shape and footprint of the probes can make difficult or facilitate a dermatologic procedure. Other points to consider are the type of storage and the need for technical service. In summary, there are key points that we need to consider when we select a dermatologic ultrasound device in dermatology or aesthetics.

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.

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.

Multiscale confocal photoacoustic dermoscopy to evaluate skin health

Background

Photoacoustic dermoscopy (PAD) is a promising branch of photoacoustic microscopy (PAM) that can provide a range of functional and morphologic information for clinical assessment and diagnosis of dermatological conditions. However, most PAM setups are unsuitable for clinical dermatology because their single-scale mode and narrow frequency band result in insufficient imaging depth or poor spatiotemporal resolution when visualizing the internal texture of the skin.

Methods

We developed a multiscale confocal photoacoustic dermoscopy (MC-PAD) with a multifunction opto-sono objective that could achieve high quality dermatological imaging. Using the objective to coordinate the spatial resolution and penetration depth, the MC-PAD was used to visualize pathophysiological biomarkers and vascular morphology from the epidermis (EP) to the dermis, which enabled us to quantify skin abnormalities without using exogenous contrast agents for human skin.

Results

The MC-PAD was shown to have the ability to differentiate between different types of cells (such as red blood cells and melanoma cells), image and quantify pigment of the skin, and visualize skin morphology and blood capillary landmarks. The MC-PAD detected a significant difference in the structures of some pigmented and vascular lesions of skin diseases compared with that of healthy skin (P<0.01). The café au lait macule (CALM) skin type was found to have a relatively higher melanin concentration and thicker stratum basale (SB) in the EP than healthy skin. The dermal vascular network of skin that had a port wine stain (PWS) had greater diameters and a denser distribution than healthy skin, as reported in clinical trials.

Conclusions

The MC-PAD has a broad range of applications for the diagnosis of human skin diseases and evaluation of the curative effect of treatments, and it can offer new perspectives in biomedical sciences.

Preliminary Clinical Experience with a Novel Optical–Ultrasound Imaging Device on Various Skin Lesions

A compact handheld skin ultrasound imaging device has been developed that uses co-registered optical and ultrasound imaging to provide diagnostic information about the full skin depth. The aim of the current work is to present the preliminary clinical results of this device. Using additional photographic, dermoscopic and ultrasonic images as reference, the images from the device were assessed in terms of the detectability of the main skin layer boundaries and characteristic image features. Combined optical-ultrasonic recordings of various types of skin lesions (melanoma, basal cell carcinoma, seborrheic keratosis, dermatofibroma, naevus, dermatitis and psoriasis) were taken with the device (N = 53) and compared with images captured with a reference portable skin ultrasound imager. The investigator and two additional independent experts performed the evaluation. The detectability of skin structures was over 90% for the epidermis, the dermis and the lesions. The morphological and echogenicity information observed for the different skin lesions were found consistent with those of the reference ultrasound device and relevant ultrasound images in the literature. The presented device was able to obtain simultaneous in-vivo optical and ultrasound images of various skin lesions. This has the potential for further investigations, including the preoperative planning of skin cancer treatment.

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.

Practical applications of ultrasound in dermatology

Ultrasound has evolved in dermatology from an experimental phase to a daily practice imaging technique. Its several advantages include its safety, good balance between penetration and resolution, high definition, and the detection of blood flow in real time. Its applications are growing and include the support of the diagnosis and extent in all axes, including depth, vascularity patterns, staging, and follow up of multiple cutaneous diseases-benign cutaneous tumors, vascular anomalies, nail lesions, skin cancer, inflammatory cutaneous diseases, and aesthetics complications.

Quantitative and anatomical imaging of dermal angiopathy by noninvasive photoacoustic microscopic biopsy

The ability to noninvasively acquire the fine structure of deep tissues is highly valuable but remains a challenge. Here, a photoacoustic microscopic biopsy (PAMB) combined switchable spatial-scale optical excitation with single-element depth-resolved acoustic detection mode was developed, which effectively coordinated the spatial resolution and the penetration depth for visualizations of skin delamination and chromophore structures up to reticular dermis depth, with the lateral resolution from 1.5 to 104 μm and the axial resolution from 34 to 57 μm. The PAMB obtained anatomical imaging of the pigment distribution within the epidermis and the vascular patterns of the deep dermal tissue, enabling quantification of morphological abnormalities of angiopathy without the need for exogenous contrast agents. The features of healthy skin and scar skin, and the abnormal alteration of dermal vasculature in port wine stains (PWS) skin were first precisely displayed by PAMB-shown multi-layered imaging. Moreover, the quantitative vascular parameters evaluation of PWS were carried out by the detailed clinical PAMB data on 174 patients, which reveals distinct differences among different skin types. PAMB captured the PWS changes in capillary-loop depth, diameter, and vascular volume, making it possible to perform an objective clinical evaluation on the severity of PWS. All the results demonstrated the PAMB can provide vascular biopsy and new indexes deep into the dermal skin noninvasively, which should be meaningful to timely evaluate the pathological types and treatment response of skin diseases. This opens up a new perspective for label-free and non-invasive biopsies of dermal angiopathy.

High-Frequency Ultrasonography and Evaporimetry in Non-invasive Evaluation of the Nail Unit

Background: The nail unit (NU) is a complex structure that performs a number of functions, including protection, defense, manipulation, and palpation. Non-invasive research methods can facilitate the recognition of NU structure and function. Evaporimetry and HF-USG due to their availability of equipment and low research costs seem to be particularly noteworthy, but so far have been assessed to a limited extent. The aim of the presented study was to check the usefulness of TOWL and HF-USG in examination of NU. Materials and Methods: A total of 58 volunteers aged 25-65 years (mean age: 41 ± 10.16 years) were qualified for the study. The subjects did not present symptoms of clinically evident onychopathy and did not suffer from any dermatoses associated with lesions occurring within the NU. Additionally, the patients did not suffer from systemic diseases that could affect NU (including heart, lung, and endocrine diseases). In all volunteers, the measurement of TOWL and 20 MHz ultrasonography [high-frequency ultrasonography (HF-USG)] with the special emphasis on determination of nail plate thickness were performed. Results: Analysis of 464 HF-USG images revealed that the nail plate presented as two hyperechoic, parallel streaks (railway sign) with a linear hypoechoic middle layer between them. Matrix was visualized as a hypoechoic structure with blurred boundaries, mostly within the fourth and fifth fingers and more often in women. We found statistically significant correlations between the type of a finger and the thickness of the nail plate both in the entire study group and taking into account gender. In the dominant hand, the results were r = -0.341; p < 0.001; r = -0.417, p < 0.001; and r = 0.337; p = 0.001 (for the whole group, for women, and for men, respectively). In the non-dominant hand, the results were r = -0.465; p < 0.001; r = -0.493, p < 0.01; and r = -0.503; p < 0.01 (for the whole group, for women, and for men, respectively). There were statistically significant differences in the thickness of the nail plates of the corresponding types of fingers between female and male NUs. Statistically significant correlations were found between the type of a finger and the TOWL value in the whole group and taking into account gender (p < 0.05), except for the non-dominant hand in men. There were no statistically significant differences in the TOWL values of the corresponding types of fingers between male and female NUs (p > 0.05). There was no statistically significant correlation between the TOWL value and the nail plate thickness in any of the tested NUs, apart from the one statistically significant correlation in nd5 (r = 0.390, p = 0.021). Conclusions: To sum up, non-invasive methods, such as HF-USG and TOWL, enable assessment of the NU and are useful in examination of its structure and function. HF-USG shows characteristic elements of NUs that can be distinguished because of differences in their echogenicity. The thickness of the nail plate and TOWL depend on the type of finger, and show a relationship with gender.

A standardized sonographic analysis of nails in psoriatic arthritis and healthy controls: Feasibility, reliability, diagnostic performance, and demographic and clinical associations

OBJECTIVES

Subunits of the nail can be evaluated by nail ultrasonography (NUSG). The purposes of this study are to document NUSG properties (both nail-based and participant-based evaluations) in patients with psoriatic arthritis (PsA) and healthy controls and to explore the final scorings.

METHODS

After the literature review and a pilot study, a consensus was reached to evaluate 12 nails and 5 parameters by NUSG: nail plate impairment (NPI), nail plate thickness (NPT), nail bed thickness (NBT), nail thickness (NT), and Doppler activity (DA); further, scorings for each parameter (NPIs, NPTs, NBTs, NTs, and DAs) were calculated. Group comparisons and diagnostic performances (with ROC curve analysis) were applied to both parameters and scorings. Final scorings to predict PsA diagnosis among the NUSG scorings were reached by regression analysis. Feasibility, reliability, and clinical associations of the scores were also performed.

RESULTS

Sixty-four patients with PsA and 26 controls (3240 baseline images) were assessed. The most affected nails, PsA/control comparisons, and the ROC analysis varied among the nails, within the higher values of PsA; therefore, 12 nails remained in the scorings. Participant-based scorings showed better content and diagnostic performances than the nail-based. Diagnostic performances, feasibility, reliability, and regression analysis of the scorings documented that NPIs, NTs, and DAs were the best. Some demographics, employee status, hemoglobin, and disease activity of the participants were associated with them.

CONCLUSIONS

The NUSG Index (NUSGI) including NPIs, NTs, and DAs is a feasible, reliable, and discriminative method to predict PsA diagnosis, with its rich content. Clinicaltrials.gov-ID: NCT04718428.

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.

European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Position Statement on Dermatologic Ultrasound

Dermatologic ultrasound is a recent application of ultrasound for the evaluation of healthy skin and appendages and their diseases. Although the scientific literature regarding this application is still not sufficient for evidence-based guidelines, general recommendations issued by scientific societies are necessary. The EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) steering committee for dermatologic ultrasound has developed a series of consensus position statements regarding the main fields of dermatologic ultrasound (technical requirement, normal skin and appendages, inflammatory skin diseases, tumoral skin diseases, aesthetic dermatology and practice-training requirements). This document is the foundation for future evidence-based recommendations and guidelines for dermatologic ultrasound practice.

Ultrasound characterization of the nail bed in patients with systemic lupus erythematosus

OBJECTIVE

To characterize the ultrasound findings of the nail plate and nail bed in systemic lupus erythematosus (SLE) and its association with nail dystrophy.

METHODS

Thirty-two SLE patients, 36 patients with osteoarthritis (OA) and 20 healthy individuals were studied. High-frequency linear ultrasound was performed in nails of the second to fifth fingers in all participants. Disease activity (SLEDAI-2K index), accrued organ damage (SLICC/ACR index), autoantibody profile, and Raynaud's phenomenon were also assessed in SLE patients.

RESULTS

Nail bed thickness in SLE patients was higher than in healthy individuals (1.25 ± 0.31 mm vs 1.17 ± 0.29 mm; P = 0.01) but lower than in OA (1.39 ± 0.37 mm; P < 0.001), while nail plate thickness was similar among groups. Nail dystrophy was found more frequently in SLE and OA than in healthy individuals. SLE patients with nail dystrophy were older than their counterparts with no dystrophy (39.4 ± 10.4 years vs 27.8 ± 5.6 years; P = 0.004), although nail dystrophy showed no association with SLICC/ACR, SLEDAI-2K, nail bed vascularity, or autoantibodies.

CONCLUSIONS

Nail bed in SLE patients is thicker than in healthy individuals but thinner than in OA patients. Nail dystrophy in SLE is associated with advanced age, but not with accrued organ damage, disease activity, Raynaud's phenomenon, or DIP synovitis assessed by ultrasound.

A preliminary study of post-progressive nail-art effects on in vivo nail plate using optical coherence tomography-based intensity profiling assessment

Nail beautification is a widely applied gender independent practice. Excessive nail beautifications and nail-arts have a direct impact on the nail structure and can cause nail disorders. Therefore, the assessment of post-progressive nail-art effects on the nail is essential to maintain optimal nail health and to avoid any undesirable disorders. In this study, in vivo nails were examined in control stage, with a nail-art stage, and after removing the nail-art stage using a 1310 nm spectral-domain optical coherence tomography (SD-OCT) system. The acquired cross-sectional OCT images were analyzed by a laboratory customized signal processing algorithm to obtain scattered intensity profiling assessments that could reveal the effects of nail beautification on the nail plate. The formation and progression of cracks on the nail plate surface were detected as an effect of nail beautification after 72 h of nail-art removal. Changes in backscattered light intensity and nail plate thickness of control and art-removed nails were quantitatively compared. The results revealed the potential feasibility of the developed OCT-based inspection procedure to diagnose post-progressive nail-art effects on in vivo nail plate, which can be helpful to prevent nail plate damages during art removal through real-time monitoring of the boundary between the nail plate and nail-art. Besides nail-art effects, the developed method can also be used for the investigation of nail plate abnormalities by examining the inconsistency of internal and external nail plate structure, which can be diagnosed with both qualitative and quantitative assessments from a clinical perspective.

Shear wave elastography and microvascular ultrasound in response evaluation to calcipotriol+betamethasone foam in plaque psoriasis

Psoriasis (PsO) is a chronic skin disease. This study aims to evaluate clinical and subclinical response to calcipotriol+betamethasone foam, in patients with PsO, comparing, for the first time, data from microvascular ultrasound (MicroV) and shear wave elastography (SWE) with Psoriasis Area and Severity Index (PASI).

METHODS

Between November 2018 and April 2019 in Tor Vergata Hospital (Roma, Italy), we enrolled 26 patients with PsO who were ageds 20-75 years, with PASI score ≥4, candidated for calcipotriol+betamethasone foam treatment. They underwent MicroV and SWE evaluation at baseline (T₀) and after 4 weeks of treatment (T₄). Clinical follow-up was carried on at T₄, T₈ and T₁₂. Student's t-test (p values<0.05 statistically significant) was used to compare SWE and PASI values.

RESULTS

At T₀, SWE stiffness values of target plaques (61.5% on elbows, 23% knees, 7.7% sacrum,7.7% legs) were significantly higher than values under healthy skin. At T₄, all patients showed a significant reduction of PASI; MicroV showed reduction in vascularisation of responsive plaques in 85% of cases, only in 15%, the vascularisation degree remained stable; and SWE values of target plaques were significantly lower compared with T₀. Only in 7.7%, there was a relapse at T₁₂.

CONCLUSIONS

Calcipotriol+betamethasone foam is a very effective topical treatment in a short-medium term follow-up in patients with PsO. MicroV and SWE evaluate response to treatment (in term of plaque vascularisation and stiffness), so they could represent promising early indicators of therapeutic response and help the physician to establish a better clinical-therapeutic management of patients with PsO.

High-frequency ultrasonography of psoriatic skin: A non-invasive technique in the evaluation of the entire skin of patients with psoriasis: A pilot study

Psoriasis is a chronic, systemic, inflammatory disorder which accelerates the life process of skin cells, based on a genetically induced deviant immune response. High-frequency ultrasonography (HF-USG) is a painless, non-invasive imaging technique that can be performed and repeated whenever the need arises. We evaluated lesional and non-lesional skin of psoriatic patients with the use of HF-USG, focusing on the immune-induced inflammation and skin thickness. Previous studies suggested that HF-USG, being a non-invasive technique, is useful as an aid to clinical evaluation of the severity of psoriatic plaques. Our goal was to determine whether the skin of psoriatic patients is influenced by the background or habits of the patients. The study included a total of 27 patients affected by psoriasis vulgaris. The thickness of the epidermis and dermis and the skin echogenicity were documented for the active plaques, as well as for the non-affected skin of all the patients included in the study, using a high-frequency ultrasonographic system. The patient's local background, sex, family history of psoriasis, smoking habits and sun exposure were analyzed. HF-USG of the psoriatic plaques exposes a three-band structure that is easily distinguished from the surrounding unaffected skin, due to a hypoechoic band in the upper dermis. Although not specific for psoriasis, it is a strong marker of inflammation. The obtained results confirm that, indeed, skin thickness is greater in lesional skin compared to non-lesional skin, by a mean of 1,180 µm (±340 µm). We consider that skin HF-USG should be used as a quantitative method in the clinical evaluation of the patients with psoriasis and may help as an objective means of assessing inflammation in lesional skin.

Diagnostic role of ultrasound elastography for nail bed involvement in psoriasis

OBJECTIVE

Psoriasis is a chronic inflammatory disease that affects the skin, joints, and nails. To investigate the efficacy of sonoelastographic evaluation for assessing nail involvement and severity in psoriasis.

MATERIALS AND METHODS

Thirty-one psoriasis patients and 31 healthy control subjects were included in the study. The nail thickness and nail bed thickness of the thumbs of all cases were measured by gray scale ultrasonography. In addition, the values of strain elastography were measured by sonoelastography.

RESULTS

Of the participants, 38 were male and 24 were female; the ratio of males and females was equal in both groups. There was no significant difference between the patient and control group in terms of gender and age. In the patient group, the mean duration of illness was 13.87 ± 9.8 years, mean PASI score was 5.53 ± 2.38, and mean NAPSI score was 33.97 ± 37.99. The nail plate thickness and elastography strain ratios were found to be statistically higher in the psoriasis group compared to the control group. There was also significant correlation between elastography strain ratios and nail thickness (P = .014), nail bed thickness (P < .001) and NAPSI scores (P = .01).

CONCLUSION

Due to the superiority of ultrasound in real-time imaging of the nail structure and the compatibility of sonographic elastography with clinical scores in the assessment of the nail bed, we believe that it can be used as a complementary method.

Imaging techniques in the diagnosis and monitoring of psoriasis

Plaque psoriasis is a chronic, immune-mediated disease, which has a multifactorial etiopathogenesis. Practical non-invasive techniques to monitor plaque psoriasis progression and treatment are necessary. Imaging techniques available for psoriasis assessment may vary in terms of resolution, depth of penetration and visual representation. This review summarizes the current developments in the field of psoriasis non-invasive imaging techniques, such as dermoscopy, conventional ultrasound and high frequency ultrasonography (HFUS), videocapillaroscopy (VC), reflectance confocal microscopy (RCM), optical microangiography (OMAG), laser Doppler imaging (LDI), multiphoton tomography (MPT) and optical coherence tomography (OCT). The aim was to collect and analyze data concerning types, indications, advantages and disadvantages of modern imaging techniques for in vivo psoriasis assessment. We focused on two main methods, videodermoscopy and HFUS, which can be included in daily dermatologists' practice and which may assist in establishing diagnosis, as well as monitoring response to topical and/or systemic therapy of psoriasis. Dermoscopy may be useful for a first evaluation and may offer an understanding of the type and distribution of blood vessels, as well as the color of the scale and the background of the lesion. Videodermoscopy allows magnification and offers a detailed evaluation of the vessel type. The utility of HFUS consists mainly in monitoring therapy response. These methods may be comparable with virtual histopathology.

Ultrasound in the Assessment of Interstitial Lung Disease in Systemic Sclerosis: A Systematic Literature Review by the OMERACT Ultrasound Group

OBJECTIVE

To provide an overview of the role of lung ultrasound (LUS) in the assessment of interstitial lung disease (ILD) in systemic sclerosis (SSc) and to discuss the state of validation supporting its clinical relevance and application in daily clinical practice.

METHODS

Original articles published between January 1997 and October 2017 were included. To identify all available studies, a detailed search pertaining to the topic of review was conducted according to guidelines of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). A systematic search was performed in PubMed and EMBASE. The quality assessment of retrieved articles was performed according to the Oxford Center for Evidence-based Medicine. The methodological quality of the studies was assessed using the Cochrane Handbook for Systematic Reviews and the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

From 300 papers identified, 12 were included for the analysis. LUS passed the filter of face, content validity, and feasibility. However, there is insufficient evidence to support criterion validity, reliability, and sensitivity to change.

CONCLUSION

Despite a great deal of work supporting the potential role of LUS for the assessment of ILD-SSc, much remains to be done before validating its use as an outcome measure in ILD-SSc.

Non-invasive imaging in dermatology and the unique potential of raster-scan optoacoustic mesoscopy

In recent years, several non‐invasive imaging methods have been introduced to facilitate diagnostics and therapy monitoring in dermatology. The microscopic imaging methods are restricted in their penetration depth, while the mesoscopic methods probe deeper but provide only morphological, not functional, information. ‘Raster‐scan optoacoustic mesoscopy’ (RSOM), an emerging new imaging technique, combines deep penetration with contrast based on light absorption, which provides morphological, molecular and functional information. Here, we compare the capabilities and limitations of currently available dermatological imaging methods and highlight the principles and unique abilities of RSOM. We illustrate the clinical potential of RSOM, in particular for non‐invasive diagnosis and monitoring of inflammatory and oncological skin diseases.

Potential of high-frequency ultrasonography in the management of atopic dermatitis

Atopic dermatitis (AD) is a chronic, highly pruritic skin disorder, with a broad spectrum of clinical manifestations, characterized by abnormal skin barrier function. High-frequency ultrasonography (HF-USG) is an instrument with potential use in a variety of skin conditions. Previous studies on HF-USG in AD reported that apparently non-lesional skin also presents barrier defects. We aimed to assess lesional and non-lesional skin of AD patients with the use of HF-USG, focusing on skin barrier function and inflammation. We included a group of AD patients and a control group. On both we performed analysis with the use of HF-USG. The thickness of the subepidermal low-echogenic band (SLEB) and the skin echogenity were recorded for active lesions, as well as non-lesional skin in all subjects included. For AD patients the clinical severity was measured using SCORing Atopic Dermatitis and correlated with Dermatology Life Quality Index (DLQI). The mean thickness of the hypoechoic band was wider in the lesional skin of AD. In the non-lesional skin of AD patients SLEB was identified to appear, but it was thinner. The skin echogenity of the control group was higher than that of AD patients. Our results indicate that skin ultrasonography is able to assess specific modifications of the AD skin. A hypoechoic band in the non-lesional skin of some AD patients may indicate subclinical eczematous lesions.

The "green nail" phenomenon in ICG-enhanced fluorescence optical imaging - a potential tool for the differential diagnosis of psoriatic arthritis

BACKGROUND AND OBJECTIVES

Early diagnosis of psoriatic arthritis poses a particular challenge. A novel fluorescence optical imaging technique, the Xiralite® system is very useful in this regard as it allows for visualization of microvasculature and perfusion. The present study is the first to systematically examine fluorescence optical signals in a large psoriatic arthritis cohort.

PATIENTS AND METHODS

In the primary study, we reviewed and analyzed extra-articular fluorescence optical signal patterns in 241 imaging sequences obtained from 187 psoriatic arthritis patients; 36 fluorescence optical sequences from 31 patients with rheumatoid arthritis served as controls. In a follow-up study, 203 consecutive fluorescence optical sequences from 54 psoriatic arthritis patients and 149 control subjects with various inflammatory rheumatic disorders were retrospectively evaluated in order to validate the primary study results in terms of the patterns previously identified.

RESULTS

Psoriatic arthritis patients exhibited three different fluorescence optical signal patterns in projection of the nails that have not been previously described. One of these patterns was the "green nail" sign, which was highly specific (97 %) for psoriatic arthritis. In the follow-up study, the specificity of this phenomenon in psoriatic arthritis was 87 % in comparison to the control cohort.

CONCLUSIONS

In the present study, fluorescence optical signals in the nail region proved to be highly specific for psoriatic arthritis. The "green nail" phenomenon seems to be of particular diagnostic interest as a potential sign of impaired microcirculation of the nail bed.

Comparison of biophysical, biomechanical and ultrasonographic properties of skin in chronic dermatitis, psoriasis and lichen planus

Background: Skin biometrology is a useful method for evaluation of inflammatory skin disorders such as dermatitis, psoriasis, and lichen planus. The current study tries to compare the biophysical features of skin in dermatitis, psoriasis, and lichen planus.

Methods: By a convenient sampling method, 22 mild to moderate chronic dermatitis, 26 psoriasis, and 21 lichen planus patients were recruited in the study. Stratum corneum (S.C.) hydration, Transepidermal water loss (TEWL), pH, erythema, melanin, sebum, friction, elasticity parameters (R0, R2, and R5), skin temperature, skin thickness, and echo-density of epidermis and dermis were measured on the lesional (selected active lesion), uninvolved perilesional, and uninvolved symmetrical skin. The average of perilesional and symmetrical uninvolved parameters was used as control, while the percentage change of each parameter [(lesion – control / control) ×100] was calculated, and compared among three diseases by ANOVA test using SPSS software version 18. The significance level was set at α=0.05.

Results: Comparison of percentage changes showed that the changes in TEWL, friction index, sebum content, R2 (gross elasticity), R5 (net elasticity), skin temperature, dermal thickness, and epidermal density are not significantly different among three skin diseases. But there were significant differences in three diseases considering the decrease in S.C. hydration (p<0.001), R0 (opposed to firmness) (p<0.001), and dermal density (p<0.001) compared to control skin. Moreover, the increase in skin pH (p<0.001), melanin content (p=0.048), erythema (p=0.023), and epidermal thickness (p <0.001) significantly differed among these diseases.

Conclusion: Dermatitis, psoriasis and lichen planus lesions had specific biophysical changes. It may be helpful in their differential diagnosis.

Remission in psoriatic arthritis-where are we now?

Advances in treatments and treatment strategies for PsA have led to many patients responding well to management of their disease, and targeting remission as a treatment goal is now a possibility. Treat to target is a strategy aimed at maximizing benefit, irrespective of the type of medication used, by monitoring disease activity and using it to guide therapy. The measurement of response to treatment has been the subject of wide discussions among experts for some time, and many instruments exist. Comparisons of the different measures and their different strengths and weaknesses is ongoing. The impact of modern imaging techniques on monitoring disease progression is also evolving, and advanced techniques using both MRI and US have the potential to improve management of PsA through identification of risk factors for poor prognosis as well as accurate assessment of inflammation and damage, including subclinical disease. Increased understanding of the pathways that drive the pathogenesis of PsA will be key to identifying specific biomarkers for the disease and developing effective treatment strategies. Targets for response, considerations for use of a treat to target strategy in PsA, different imaging techniques and serological aspects of remission are all discussed in this review, and areas for further research are identified.

Ultrasonographic Criteria for Diagnosing Unilateral and Bilateral Retronychia

OBJECTIVES

To assess the main characteristics of retronychia on ultrasonography (US) and to propose US criteria for diagnosing unilateral and bilateral cases according to the digit.

METHODS

We conducted a case-control study with retrospective, descriptive, and statistical analyses of the US images of 210 nails: 43 with retronychia and 167 normal nails. The Student t test, Fisher exact test, and Kruskal-Wallis test, among other tests, were performed. P < .05 was considered significant.

RESULTS

Seventy percent of the patients were females, and the most affected digit was the big toe. Significant US diagnostic criteria were as follows: criterion 1, hypoechoic halo surrounding the origin of the nail plate; criterion 2, distance between the origin of the nail plate and the base of the distal phalanx of 5.1 mm or less in big toes and thumbs and/or a difference of 0.5 mm of this distance or greater between the affected nail and the contralateral healthy nail; and criterion 3, proximal nail fold thickness of 2.2 mm or greater for male patients or 1.9 mm or greater for female patients and/or a proximal nail fold 0.3 mm thicker or greater in comparison with the contralateral healthy nail. Cutoff points, sensitivity, and specificity with a 95% confidence interval were defined for each criterion according to the digit in cases with unilateral and bilateral involvement.

CONCLUSIONS

Ultrasonography can support the diagnosis of retronychia in unilateral and bilateral cases.

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

Nail unit ultrasound: a complete guide of the nail diseases

INTRODUCTION

The nails have a functional and esthetic importance for patients. Almost always, the nail disorders are diagnosed on the basis of clinical findings, but imaging methods may be required for a better assessment. These imaging methods, such as ultrasound and magnetic resonance, may help to establish an accurate diagnosis. Magnetic resonance imaging is not widely available and sometimes may be very expensive; that is why, ultrasound is an excellent imaging modality. Our objective is to expose the nail unit anatomy, the nail unit anatomy in ultrasound, and some of the frequent pathologies found in our daily practice.

METHODS

A review of the literature was done to review the anatomy, technical aspects, and different findings in normal and abnormal nail unit ultrasound.

RESULTS

Ultrasound offers an appropriate alternative for the evaluation of the nail unit, allows a real-time evaluation of each one of the components of the nail unit with an optimal visualization of these structures, and allows the evaluation of the thickness of the components, the vascularity, and blood flow by Doppler application. In addition, the nail unit disorder, such as infectious diseases, inflammatory and rheumatologic conditions, nail tumors, among others, may be assessed, not only in the diagnosis but also in the follow-up. Pre-surgical evaluation, surgical follow-up, and some procedures, such as biopsies, may be done by this technique.

CONCLUSIONS

Ultrasound is an excellent technique for evaluation of normal anatomy, diagnosis, and follow-up of patients with nail unit diseases. This is an alternative for other imaging methods and may be used for an accurate diagnosis approach.

Nail Enthesis Ultrasound in Psoriasis and Psoriatic Arthritis: A Report from the 2016 GRAPPA Annual Meeting

Musculoskeletal ultrasonography is gaining favor in the evaluation of enthesitis in patients with psoriasis and psoriatic arthritis (PsA). Imaging modalities have shown that the enthesis of the distal interphalangeal joint has a close relationship to the nail itself. Studies have focused on the structure and morphology of nails to determine an association between psoriasis nail changes and the presence or severity of PsA. With the use of higher frequency probes, power Doppler (PD) can determine subclinical inflammation of the area under ultrasound examination. At the 2016 meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), we proposed an ultrasonographic index for the assessment of the nail enthesis to identify the morphologic and PD findings of the nail, with the potential that both rheumatologists and dermatologists can use it to evaluate their patients.

Posttraumatic Retronychia of the Foot with Clinical and Ultrasound Correlation

Retronychia, the posterior embedding of the nail bed into the proximal nail fold, can be a complex clinical dermatologic diagnosis that may mimic other inflammatory ungual diseases or tumors of the nail. It has been related to a history of severe systemic conditions that secondarily affect the nail matrix and is commonly associated with onychomadesis. We present a case of retronychia of the foot with a purely traumatic origin, nonconcomitant with onychomadesis, that was diagnosed by color Doppler ultrasound in a long-time practitioner of martial arts who was otherwise healthy. Color Doppler ultrasound is an excellent imaging technique for supporting the diagnosis of retronychia. It provides information on the exact location and morphology of the nail plate as well as the presence of inflammatory signs in the ungual and proximal periungual regions. Additionally, this imaging technique can support the differential diagnosis with other nail conditions. Since there are many sports or activities that can potentially injure the toenails, retronychia may be an underestimated entity and the present case can raise the awareness of this condition and show the usefulness of color Doppler ultrasound.