This update and revision of the international guideline for urticaria was developed following the methods recommended by Cochrane and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group. It is a joint initiative of the Dermatology Section of the European Academy of Allergology and Clinical Immunology (EAACI), the Global Allergy and Asthma European Network (GA²LEN) and its Urticaria and Angioedema Centers of Reference and Excellence (UCAREs and ACAREs), the European Dermatology Forum (EDF; EuroGuiDerm), and the Asia Pacific Association of Allergy, Asthma and Clinical Immunology with the participation of 64 delegates of 50 national and international societies and from 31 countries. The consensus conference was held on 3 December 2020. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS). Urticaria is a frequent, mast cell–driven disease that presents with wheals, angioedema, or both. The lifetime prevalence for acute urticaria is approximately 20%. Chronic spontaneous or inducible urticaria is disabling, impairs quality of life, and affects performance at work and school. 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.

Older persons have higher autoimmunity but a lower prevalence of autoimmune diseases. A possible explanation for this is the expansion of many protective regulatory mechanisms highly characteristic in the elderly. Of note is the higher production of peripheral T-regulatory cells. The frequent development of autoimmunity in the elderly was suggested to take place in part due to the selection of T cells with increased affinity to self-antigens or to latent viruses. These cells were shown to have a greater ability to be pro-inflammatory, thereby amplifying autoimmunity. During aging, thymic T-regulatory cell output decreases in association with the loss of thymic capacity to generate new T cells. However, to balance the above mentioned autoimmunity and prevent the development of autoimmune diseases, there is an age-related increase in peripheral CD4+ CD25highFoxP3+ T-regulatory cells. It remains unclear whether this is an age-related immune dysfunction or a defense response. Whatever the reason, the expansion of T-regulatory cells requires payment in terms of an increased incidence of cancer and higher susceptibility to infections.

Chronic spontaneous urticaria (CSU) is defined as the spontaneous development of itchy hives and/or angioedema due to known or unknown causes that last for at least 6 weeks. At any given time, CSU is believed to affect 0.5–1% of the global population. Omalizumab (a recombinant, humanized anti-immunoglobulin-E antibody) is the only approved treatment for antihistamine refractory CSU. However, ~ 30% of patients remain symptomatic at licensed doses of omalizumab 150 mg and 300 mg, even after a treatment period of over 6 months. In the recent years, there have been several studies on updosing of the drug, suggesting that the individualized approach for urticaria treatment with omalizumab is useful. In this article, we provide an overview of these studies and the real-world data on omalizumab updosing as it became necessary to obtain complete CSU symptom control in a proportion of patients. Published observational studies (from June 2003 to October 2019) on the updosing of omalizumab in CSU were identified using PubMed and Ovid databases. Reports mainly show that updosing/dose adjustment evaluated with the assessment of disease activity (Urticaria Activity Score) and control (Urticaria Control Test) achieves better clinical response to omalizumab with a good safety profile in a pool of patients with CSU. These real-world data will provide an overview of updosing of omalizumab in CSU and aid in setting informed clinical practice treatment expectations.

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.