This update and revision of the international guideline for urticaria was developed in accordance with the methods recommended by Cochrane and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group. It is an initiative of the Global Allergy and Asthma Excellence Network (GA ² LEN) and its Urticaria and Angioedema Centers of Reference and Excellence (UCAREs and ACAREs), with the participation of 210 delegates from 107 national and international societies, from 59 countries. The consensus conference was held on December 6th, 2024. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS). Urticaria is a frequent, mast cell‐driven disease, defined by a rapid appearance of wheals, angioedema, or both. The lifetime prevalence of acute urticaria is estimated to be approximately 20%. Chronic urticaria, categorized as either chronic spontaneous urticaria or chronic inducible urticaria, is disabling, impairs quality of life, and affects performance at work and school, however, novel therapies are available. This updated version of the international guideline for urticaria covers the definition and classification of urticaria and outlines expert‐guided and evidence‐based diagnostic and therapeutic approaches for the different subtypes of urticaria.

Introduction: The COVID‐19 pandemic dramatically disrupts health care around the globe. The impact of the pandemic on chronic urticaria (CU) and its management are largely unknown.Aim: To understand how CU patients are affected by the COVID‐19 pandemic; how specialists alter CU patient management; and the course of CU in patients with COVID‐19.Materials and Methods: Our cross‐sectional, international, questionnaire‐based, multicenter UCARE COVID‐CU study assessed the impact of the pandemic on patient consultations, remote treatment, changes in medications, and clinical consequences.Results: The COVID‐19 pandemic severely impairs CU patient care, with less than 50% of the weekly numbers of patients treated as compared to before the pandemic. Reduced patient referrals and clinic hours were the major reasons. Almost half of responding UCARE physicians were involved in COVID‐19 patient care, which negatively impacted on the care of urticaria patients. The rate of face‐to‐face consultations decreased by 62%, from 90% to less than half, whereas the rate of remote consultations increased by more than 600%, from one in 10 to more than two thirds. Cyclosporine and systemic corticosteroids, but not antihistamines or omalizumab, are used less during the pandemic. CU does not affect the course of COVID‐19, but COVID‐19 results in CU exacerbation in one of three patients, with higher rates in patients with severe COVID‐19.Conclusions: The COVID‐19 pandemic brings major changes and challenges for CU patients and their physicians. The long‐term consequences of these changes, especially the increased use of remote consultations, require careful evaluation.

Background: Cold urticaria (ColdU), that is, the occurrence of wheals or angioedema in response to cold exposure, is classified into typical and atypical forms. The diagnosis of typical ColdU relies on whealing in response to local cold stimulation testing (CST). It can also manifest with cold‐induced anaphylaxis (ColdA). We aimed to determine risk factors for ColdA in typical ColdU.Methods: An international, cross‐sectional study COLD‐CE was carried out at 32 urticaria centers of reference and excellence (UCAREs). Detailed history was taken and CST with an ice cube and/or TempTest^® performed. ColdA was defined as an acute cold‐induced involvement of the skin and/or visible mucosal tissue and at least one of: cardiovascular manifestations, difficulty breathing, or gastrointestinal symptoms.Results: Of 551 ColdU patients, 75% (n = 412) had a positive CST and ColdA occurred in 37% (n = 151) of the latter. Cold‐induced generalized wheals, angioedema, acral swelling, oropharyngeal/laryngeal symptoms, and itch of earlobes were identified as signs/symptoms of severe disease. ColdA was most commonly provoked by complete cold water immersion and ColdA caused by cold air was more common in countries with a warmer climate. Ten percent (n = 40) of typical ColdU patients had a concomitant chronic spontaneous urticaria (CSU). They had a lower frequency of ColdA than those without CSU (4% vs. 39%, p = .003). We identified the following risk factors for cardiovascular manifestations: previous systemic reaction to a Hymenoptera sting, angioedema, oropharyngeal/laryngeal symptoms, and itchy earlobes.Conclusion: ColdA is common in typical ColdU. High‐risk patients require education about their condition and how to use an adrenaline autoinjector.