Background: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe multi-organ drug hypersensitivity reaction (DHR) involving T cells. DRESS patients have a heightened risk (~25%) of developing multiple drug hypersensitivity (MDH) to unrelated drugs from the first reaction. This project aims to characterise DRESS, focusing on those with and without MDH, to identify potential biomarkers for further drug reactions. Methods: This multicentre cross-sectional study analysed clinical features and immune responses, including T cell activation and in vitro cytokine secretion using Cyto-LTT. The study included 20 DRESS patients (12 with MDH), 8 maculopapular exanthema (MPE) patients (4 with MDH), and a control group of 9 healthy donors (HD). Clinical assessments included detailed histories, skin testing, and the RegiSCAR score for diagnosing DRESS. Results: The Cyto-LTT improved diagnostic sensitivity, particularly in DRESS patients, identifying 19% of drugs that were negative by skin testing. MDH patients’ leukocytes exhibited stronger and broader secretions of cytokines and cytotoxic mediators, up to ten-fold higher compared to DHR patients with a single drug sensitisation. T cells from recovered delayed DHR patients exhibited signs of chronic activation after resolution, with elevated CD69 and PD-1 but reduced CD38 and OX-40 levels compared to HD. Conclusion: Recovered delayed DHR patients display an altered T cell activation profile suggesting a “chronic disease” state, possibly explaining the heightened risk of MDH. Increased cytokine secretions, such as stimulation index > 10, especially for cytotoxic mediators, may differentiate those at risk for MDH.

Aim: The 4th Davos Declaration, convened during the Global Allergy Forum (GAF) in Davos, aimed to elevate patient care for patients with atopic dermatitis (AD) by uniting experts and stakeholders. The forum addressed the high prevalence of AD, with a strategic focus on advancing research, treatment, and management to meet the evolving challenges in the field. Methods: This multidisciplinary forum brought together top leaders from research, clinical practice, policy, and patient advocacy to discuss the critical aspects of AD, including neuroimmunology, environmental factors, comorbidities, and breakthroughs in prevention, diagnosis, and treatment. The discussions were geared towards fostering a collaborative approach to integrate these advancements into practical, patient-centric care. Results The forum underlined the mounting burden of AD, attributing it to significant environmental and lifestyle changes. It acknowledged the progress in understanding AD and in developing targeted therapies but recognized a gap in translating these innovations into clinical practice. Emphasis was placed on the need for enhanced awareness, education, and stakeholder engagement to address this gap effectively and to consider environmental and lifestyle factors in a comprehensive disease management strategy. Conclusion: The 4th Davos Declaration marks a significant milestone in the journey to improve care for people with AD. By promoting a holistic approach that combines research, education, and clinical application, the Forum sets a roadmap for stakeholders to work together to improve patient outcomes in AD, reflecting a commitment to adapt and respond to the dynamic challenges of AD in a changing world.