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

Nail psoriasis and nail lichen planus: Updates on diagnosis and management

BACKGROUND

Inflammatory diseases of the nail, including nail psoriasis and nail lichen planus, are associated with significant disease burden and have a negative impact on quality of life. Diagnosis is often delayed, especially when patients present without cutaneous findings. Therefore, recognizing clinical signs and symptoms of inflammatory nail diseases, and initiating timely and appropriate treatment, is of utmost importance.

OBJECTIVE

We review recent studies on diagnostic techniques, discuss severity grading and scoring systems, and describe consensus treatment recommendations for nail psoriasis and nail lichen planus.

METHODS

An updated literature review was performed using the PubMed database on studies assessing diagnostic techniques or treatment modalities for nail psoriasis and nail lichen planus.

RESULTS

Recent studies on diagnostic techniques for inflammatory nail disease have focused on use of dermoscopy, capillaroscopy, and ultrasound modalities. Treatment of these conditions is dichotomized into involvement of few (≤3) or many (>3) nails. Recent psoriatic therapeutics studied for nail outcomes include brodalumab, tildrakizumab, risankizumab, deucravacitinib, and bimekizumab, while emerging treatments for nail lichen planus include JAK inhibitors and intralesional platelet rich plasma injections.

CONCLUSIONS

We emphasize the need for increased awareness and expanded management strategies for inflammatory nail diseases to improve patient outcomes.

Nail Ultrasound in Psoriasis and Psoriatic Arthritis-A Narrative Review

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

Nailfold capillaroscopy as diagnostic test in patients with psoriasis and psoriatic arthritis: A systematic review

Up to 30 % of patients with psoriasis (PsO) develop psoriatic arthritis (PsA), and diagnosis can be difficult. Nailfold capillaroscopy (NC) is an easily applicable, non-invasive procedure to assess skin microcirculation. This systematic review investigates NC as diagnostic tool for PsO and PsA, including correlations between NC outcome measures to clinical and laboratory outcome measures. This systematic review was built on the PICO and PRISMA guidelines. In total 22 relevant studies were found Searching in the Web of Science, PubMed and Embase, latest update June 13th, 2022. The following NC outcome measures are found to be significantly more prevalent in PsO patients than healthy controls: reduced density, reduced length and more abnormal morphology. Likewise, in PsA patients, reduced density, more abnormal morphology, more microhaemorrhages and fewer hairpin shapes are found to be significantly more prevalent. Results were non-conclusive in terms of disease activity and duration with NC findings. Random-effects meta-analysis showed a significant reduction of density in PsO patients compared to healthy controls (studies: 6, n = 249; SMD = -0.91; 95 % CI [-1.41, -0.40], p = 0.0058, heterogeneity I²=74 %, AUC = 0.740) and in PsA patients compared to healthy controls (studies: 5, n = 130; SMD = -1.22; 95 % CI [-2.38, -0.06], p = 0.0432, heterogeneity I²=89 %, AUC = 0.806). No NC outcome measures were overall conclusive in differentiating PsO from PsA. Considering the conflicting results and small sample sizes further large-scale research on the identification of capillaroscopic changes in PsO and PsA and correlations with standardised clinical and laboratory outcome measures are necessary.

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.

Investigating the efficacy and safety of calcipotriol/betamethasone dipropionate foam and laser microporation for psoriatic nail disease-A hybrid trial using a smartphone application, optical coherence tomography, and patient-reported outcome measures

There is a lack of efficacious topical treatments for patients suffering from psoriatic nail disease (PND). We investigated the efficacy of Calcipotriol-Betamethasone Dipropionate (Cal/BD) foam with and without ablative fractional laser (AFL) in patients with PND. A total of 144 nails from 11 patients were treated in a 24-week long, open-label, randomized, intra-patient controlled proof-of-concept hybrid trial. In addition to daily Cal/BD foam application, half of each patient's psoriatic nails were randomized to receive optical coherence tomography (OCT)-guided AFL treatment at baseline, 6-, and 12-week follow-ups. In-clinic assessment (N-NAIL), patient-reported outcomes (PROMs), and drug consumption were supplemented by remote evaluation of 15 subclinical OCT features, smartphone app-based safety monitoring, and photo-based assessment (NAPSI). After 24 weeks of Cal/BD foam treatment, patients achieved a significant improvement (p < 0.001) in both clinical (N-NAIL -76%, NAPSI -68%) and subclinical (OCT -43%) PND severity as well as a 71% reduction in PROMs. AFL-assisted Cal/BD treatment led to higher clinical (N-NAIL -85%, NAPSI -78%) and OCT-assessed (-46%) reduction of PND signs than Cal/BD alone (N-NAIL -66%, NAPSI -58%, OCT -37%), but did not reach statistical significance. Smartphone app images documented adverse events and mild local skin reactions, particularly erythema (75%), laser-induced swelling (28%), and crusting (27%). This hybrid trial demonstrated a reduction in clinical NAPSI and N-NAIL scores, subclinical OCT features, and PROMs, suggesting that Cal/BD foam is a safe and efficacious treatment for PND. Larger trials are warranted to prove the clinical benefit of AFL pretreatment as a Cal/BD delivery enhancer.