Background Chronic nodular prurigo (CNPG) is a condition characterized by chronic itch, a prolonged scratching behaviour and the presence of pruriginous nodules. A comprehensive understanding of this condition, especially regarding its clinical characteristics and impact on quality of life is still lacking. Objectives Aim of this pan-European multicentre cross-sectional study was to establish the clinical profile of CNPG, including its associated burden. Methods Fifteen centres from 12 European countries recruited CNPG patients presenting at the centre or using the centres' own databases. Patients were asked to complete a questionnaire in paper or electronic format. Demography, current co-morbidities, underlying disease, itch intensity, additional sensory symptoms, quality of life, highest burden and emotional experience of itch were assessed. Results A total of 509 patients (210 male, median age: 64 years [52; 72]) were enrolled. Of these, 406 reported itch and CNPG lesions in the previous 7 days and qualified to complete the whole questionnaire. We recorded moderate to severe worst itch intensity scores in the previous 24 h. Scores were higher in patients with lower educational levels and those coming from Eastern or Southern Europe. Most patients experience itch often or always (71%) and report that their everyday life is negatively affected (53%). Itch intensity was considered to be the most burdensome aspect of the disease by 49% of the patients, followed by the visibility of skin lesions (21%) and bleeding of lesions (21%). The majority of patients was unaware of an underlying condition contributing to CNPG (64%), while psychiatric diseases were the conditions most often mentioned in association with CNPG (19%). Conclusions This multicentre cross-sectional study shows that itch is the dominant symptom in CNPG and reveals that the profile of the disease is similar throughout Europe.

Chronic nodular prurigo is characterized by recalcitrant itch. Patient perspectives on therapeutic goals, satisfaction with therapy and efficacy of therapeutic regimens for this condition are unknown. This questionnaire study examined these issues in 406 patients with chronic nodular prurigo from 15 European dermatological centres. Improvements in itch, skin lesions and sleep were the most important goals. Emollients, topical corticosteroids and antihistamines were the most frequently used treatments, while a minority of patients were prescribed potent medications, such as systemic immunosuppressants and gabapentinoids. Most patients were not satisfied with their previous therapy (56.8%), while 9.8% did not receive any therapy despite having active disease. A substantial number of respondents (28.7%) considered none of the therapeutic options effective. Although chronic nodular prurigo is a severe disease, most patients were not treated with potent systemic drugs, which may contribute to the high levels of dissatisfaction and disbelief in available therapies. Specific guidelines for chronic nodular prurigo and the development of novel therapies are necessary to improve care.

Background Chronic prurigo (CPG) is a distinct disease characterized by chronic pruritus, history and/or signs of prolonged scratching and multiple pruriginous lesions. It may present with various clinical manifestations, including papules, nodules, plaques or umbilicated lesions. Some patients with chronic pruritus show pruriginous linear and scaring scratch lesions (LSSL) and it is unclear whether these lesions belong to the spectrum of CPG. Objective To achieve a consensus on the classification of pruriginous LSSL and establish criteria to differentiate them from similar appearing conditions of different nature. Methods Members of the Task Force Pruritus (TFP) of the European Academy of Dermatology and Venereology participated in the consensus conference, discussing representative clinical cases. Using the Delphi method, consensus was reached when ≥75% of members agreed on a statement. Results Twenty‐one members of the TFP with voting rights participated in the meeting. It was consented that LSSL occurs due to chronic pruritus and prolonged scratching, and share common pathophysiological mechanisms with CPG. LSSL were thus considered as belonging to the spectrum of CPG and the term ‘linear prurigo’ was chosen to describe this manifestation. Conclusion Considering linear prurigo as belonging to the spectrum of CPG has important clinical implications, since both the diagnostic and therapeutic approach of these patients should be performed as recommended for CPG. Importantly, linear prurigo should be differentiated from self‐inflicted skin lesions as factitious disorders or skin picking syndromes. In the latter, artificial manipulation rather than pruritus itself leads to the development of cutaneous lesions, which can show clinical similarities to linear prurigo.

Psoriasis is a widespread inflammatory skin disease affecting about 2% of the general population. Recently, treatments that specifically target key proinflammatory cytokines driving the disease have been developed to complement conventional therapies with unspecific antiproliferative or anti-inflammatory effects. Efficient monitoring of treatment efficacy in the context of precision medicine and the assessment of new therapeutics require accurate noninvasive readouts of disease progression. However, characterization of psoriasis treatment remains subjective based on visual and palpatory clinical assessment of features observed on the skin surface. We hypothesized that optoacoustic (photoacoustic) mesoscopy could offer label-free assessment of inflammation biomarkers, extracted from three-dimensional (3D) high-resolution images of the human skin, not attainable by other noninvasive methods. We developed a second-generation ultra-broadband optoacoustic mesoscopy system, featuring sub–10-μm resolution and advanced motion correction technology, and performed 80 longitudinal measurements of 20 psoriatic skin plaques in humans under conventional inpatient treatment or receiving biologics with concomitant topical corticosteroid treatment. Optoacoustic image analysis revealed inflammatory and morphological skin features that indicated treatment efficacy with sensitivity, accuracy, and precision that was not possible using clinical metrics. We identify 3D imaging biomarkers that reveal responses to treatment and offer the potential to facilitate disease and treatment characterization. Our findings suggest that optoacoustic mesoscopy may offer a method of choice for yielding both qualitative and quantitative evaluations of skin treatments that are inaccessible by other methods, potentially enabling optimized therapies and precision medicine in dermatology.