Evolution of urticarial vasculitis: a clinical, dermoscopic and histopathological study

Dermoscopic Features of Cutaneous Vasculitis

INTRODUCTION

Dermoscopy has become widespread in the diagnosis of inflammatory skin diseases. Cutaneous vasculitis (CV) is characterized by inflammation of vessels, and a rapid and reliable technique is required for the diagnosis.

OBJECTIVES

We aimed to define CV dermoscopic features and increase the diagnostic accuracy of dermoscopy with machine learning (ML) methods.

METHODS

Eighty-nine patients with clinically suspected CV were included in the study. Dermoscopic images were obtained before biopsy using a polarized dermoscopy. Dermoscopic images were independently evaluated, and interobserver variability was calculated. Decision Tree, Random Forest, and K-Nearest Neighbors were used as ML classification models.

RESULTS

The histopathological diagnosis of 58 patients was CV. Three patterns were observed: homogeneous pattern, mottled pattern, and meshy pattern. There was a significant difference in background color between the CV and non-CV groups (P = 0.001). The milky red and livedoid background color were specific markers in the differential diagnosis of CV (sensitivity 56.7%, specificity 96.3%, sensitivity 29.4%, specificity 99.2%, respectively). Red blotches were significantly more common in CV lesions (P = 0.038). Red dots, comma vessels, and scales were more common in the non-CV group (P = 0.002, P = 0.002, P = 0.003, respectively). Interobserver agreement was very good for both pattern (κ = 0.869) and background color analysis (κ = 0.846) (P < 0.001). According to ML classifiers, the background color and lack of scales were the most significant dermoscopic aspects of CV.

CONCLUSIONS

Dermoscopy may guide as a rapid and reliable technique in CV diagnosis. High accuracy rates obtained with ML methods may increase the success of dermoscopy.

Dermoscopic Features of Different Forms of Cutaneous Mastocytosis: A Systematic Review

The term mastocytosis refers to a heterogeneous group of disorders characterised by accumulation of clonal mast cells in different organs, most commonly in the skin. Little is known about the role of dermoscopy in the diagnostics of mastocytosis. To date, no systematic review on the dermoscopic features of cutaneous mastocytosis has been performed. The aim of this study was to summarise the current knowledge in the field as well as to identify the knowledge gaps to show possible directions for further studies, based on a systematic search of PubMed, Scopus, and Web of Science databases and related references published before 3 January 2022. Dermoscopic features, type of dermoscope, polarisation mode, magnification, and number of cases were analysed. In total, 16 articles were included in this review (3 case series and 13 case reports), analysing 148 patients with different variants of cutaneous mastocytosis; all of the studies analysed had a low level of evidence (V). The main dermoscopic features of urticaria pigmentosa included brown structureless areas, brown lines arranged in a network, and linear vessels distributed in a reticular pattern, with this last finding also being typical of telangiectasia macularis eruptiva perstans. The presence of either circumscribed yellow structureless areas or diffuse yellowish background was a constant pattern of mastocytoma, while nodular, pseudoangiomatous xanthelasmoid, and plaque-type mastocytosis were typified by light-brown structureless areas and/or pigment network, though the first two variants also showed yellow/yellow-orange structureless areas. Finally, pigmented streaks of radial distribution surrounding hair follicles were described to be a pathognomonic dermoscopic feature of pseudoxanthomatous mastocytosis. Although this review shows that the various clinical forms of cutaneous mastocytosis may feature diagnostic dermoscopic clues, it also underlines the need for further investigation as several relevant data are missing, including evaluation of dermoscopic pattern according to anatomical locations or “lesion age”, studies on rare mastocytosis variants, evaluation of the prognostic role of dermoscopy in the context of systemic involvement, and comparative analyses with common clinical mimickers.

Development of a clinical-dermoscopic model for the diagnosis of urticarial vasculitis

The clinical criteria for the diagnosis of urticarial vasculitis lack accuracy, according to previous studies. The aim of the study was to assess the accuracy of a clinical and a clinical-dermoscopic model for the differential diagnosis of chronic spontaneous urticaria (CSU) and urticarial vasculitis (UV). Dermoscopic images of lesions with histopathologically confirmed diagnosis of CSU and UV were evaluated for the presence of selected criteria (purpuric patches/globules (PG) and red linear vessels). Clinical criteria of CSU and UV were also registered. Univariate and adjusted odds ratios were calculated. Multivariate regression analyses were conducted separately for clinical variables (clinical diagnostic model) and for both clinical and dermoscopic variables (clinical-dermoscopic diagnostic model). 108 patients with CSU and 27 patients with UV were included in the study. The clinical-dermoscopic model notably showed higher diagnostic sensitivity than the clinical approach (63% vs. 44%). Dermoscopic purpuric patches/globules (PG) was the variable that better discriminated UV, increasing by 19-fold the odds for this diagnosis. In conclusion, dermoscopy helps the clinical discrimination between CSU and UV. The visualization of dermoscopic PG may contribute to optimize decisions regarding biopsy in patients with urticarial rashes.

Management of urticarial vasculitis: A worldwide physician perspective

BACKGROUND

Urticarial vasculitis (UV) is a rare type of leukocytoclastic vasculitis characterized by long lasting urticarial skin lesions and poor response to treatment. As of yet, no clinical guidelines, diagnostic criteria, or treatment algorithms exist, and the approaches to the diagnostic workup and treatment of UV patients may differ globally. We conducted an online survey to examine how UV patients are diagnosed and treated by international specialists and to reveal the greatest challenges in managing UV patients worldwide.

METHODS

Distribution of the questionnaire included an email to individuals in the World Allergy Organization (WAO) database, with no restrictions applied to the specialty, affiliation, or nationality of the participants (November 2018). The email contained a link (Internet address) to the online questionnaire. Responses were anonymous. The link to the questionnaire was further sent to the network of Urticaria Centers of Reference and Excellence (UCARE) in the Global Allergy and Asthma European Network (GA2LEN) as well as to the Turkish Dermatology Society and the Japanese Society of Allergology, who distributed the link to their members. In addition, the survey link was posted online in the group of the Russian Society of Allergologists and Immunologists.

RESULTS

We received 883 completed surveys from physicians in 92 countries. UV was reported to be rare in clinical practice, with an average of 5 patients per physician per year. More than two-thirds of physicians reported wheals, burning of the skin, and residual hyperpigmentation in 60-100% of UV patients. The most frequently reported reason for receiving referrals of patients with UV was to establish the diagnosis. The most important features for establishing the diagnosis of UV were wheals of longer than 24 hours duration (72%), the results of skin biopsy (63%), and post-inflammatory hyperpigmentation (46%). The most common tests ordered in UV patients were complete blood count, erythrocyte sedimentation rate, C-reactive protein, complement components, antinuclear antibodies, and skin biopsy. Physicians considered UV to be of unknown cause in most patients, and drugs and systemic lupus erythematosus to be the most common identifiable causes. Two of 3 physicians reported that they use second-generation antihistamines in standard dose as the first-line therapy in patients with UV. The greatest perceived challenges in the management of UV were the limited efficacy of drugs and the absence of clinical guidelines and treatment algorithms.

CONCLUSIONS

UV is a challenging disease. Skin biopsy, a gold standard for UV diagnosis, is not performed by many physicians. This may lead to misdiagnosis of UV, for example, as chronic spontaneous urticaria, and to inadequate treatment. International consensus-based recommendations for the classification of UV and the diagnostic workup and treatment, as well as prospective studies evaluating potentially safe and effective drugs for the treatment of UV, are necessary.

Dermoscopy of Common Inflammatory Disorders

In addition to its "traditional" application for the early diagnosis of melanoma and nonmelanoma skin cancers, dermoscopy gains appreciation in fields beyond dermato-oncology. Nowadays, dermoscopy has been established as a reliable adjunctive tool to the everyday clinical practice of general dermatology. Morphology and distribution of vascular structures, background colors, follicular abnormalities, and the presence of scales are important features that should be evaluated. Clinical examination remains the undoubted mainstay of diagnosis in inflammatory and infectious diseases.