These recommendations for the definition, diagnosis and management of chronic inducible urticaria (CIndU) extend, revise and update our previous consensus report on physical urticarias and cholinergic urticaria (Allergy, 2009). The aim of these recommendations is to improve the diagnosis and management of patients with CIndU. Our recommendations acknowledge the latest changes in our understanding of CIndU, and the available therapeutic options, as well as the development of novel diagnostic tools.These recommendations for the definition, diagnosis, and management of chronic inducible urticaria (CIndU) extend, revise, and update our previous consensus report on physical urticarias and cholinergic urticaria (1), a joint initiative of the EAACI (European Academy of Allergology and Clinical Immunology) Dermatology Section, the GA 2 LEN (Global Allergy and Asthma European Network) task force on urticaria, the EDF (European Dermatology Forum), and UNEV (urticaria network e.V.). Changes to the 2009 consensus report reflect the results of studies published since then. Chronic inducible urticariasChronic inducible urticarias (CIndUs) are a subgroup of chronic urticaria, a group of diseases characterized by the recurrence of itchy wheals and/or angioedema for longer than 6 weeks [ Table 1, (2)]. Most CIndUs present with wheals, angioedema, or both. Within the group of CIndU, symptomatic dermographism/urticaria factitia, cold and heat urticarias, delayed pressure urticaria, solar urticaria, and vibratory angioedema are defined as physical urticarias. Nonphysical CIndUs include cholinergic urticaria, contact urticaria, and aquagenic urticaria. CIndUs, in contrast to chronic spontaneous urticaria (CSU), are characterized by the need for specific triggers for wheals, angioedema, or both of these symptoms to develop. Wheals and angioedema in CIndU patients develop only and reproducibly in response to the trigger stimulus that is specific for their condition (e.g., cold exposure in cold urticaria). CIndU signs and symptoms are usually confined to skin areas that are exposed to the Allergy 71 (2016) 780-802

Physical and cholinergic urticariasPhysical urticaria is a heterogeneous group of inducible conditions that includes cold contact urticaria, symptomatic dermographism/urticaria factitia, heat contact urticaria, delayed pressure urticaria, and vibratory urticaria/ angioedema. Physical urticarias are induced by exogenous physical triggers acting on the skin, including thermal (cold, heat), electromagnetic radiation (solar radiation) and mechanic triggers (friction, pressure, vibration). Physical urticarias need to be accurately distinguished from spontaneous urticaria as well as other inducible forms of urticaria (Table 1).Cholinergic urticaria, which is also an inducible form of urticaria, is not classified as a physical urticaria (Table 1), because its symptoms are induced by an increase in the body core temperature and not by an exogenous physical trigger acting on the skin (2). The panel acknowledges that atypical and rare variants of cholinergic urticaria and of the physical urticarias not discussed below exist, but the discussion of these forms is beyond the scope of this article.Physical urticarias and cholinergic urticaria are diagnosed on the basis of an indicative medical history and positive provocation testing. All patients with a history suggestive of a physical urticaria or cholinergic urticariaThe recommendations for the definition and diagnosis presented in this position paper are the result of a panel consensus meeting held in December 2008 in Berlin. This consensus meeting was a joint initiative of EAACI (European Academy of Allergology and Clinical Immunology) Dermatology Section, the EU-funded network of excellence, GA 2 LEN (Global Allergy and Asthma European Network), the EDF (European Dermatology Forum) and UNEV (urticaria network e.V.). The aim of these recommendations is to improve the diagnosis and management of patients with physical urticaria or cholinergic urticaria and to promote research and a better understanding of these diseases. Our recommendations used the paper produced by a 1996 expert meeting (1) and they acknowledge the latest changes in our understanding of physical urticarias and cholinergic urticaria as well as the recent development of novel diagnostic tools. In addition, this consensus paper highlights areas of need for further research.

No abstract

Cold urticaria (ColdU) is a common form of chronic inducible urticaria characterized by the development of wheals, angioedema or both in response to cold exposure. Recent research and guideline updates have advanced our understanding and management of ColdU. Today, its pathophysiology is thought to involve the cold‐induced formation of autoallergens and IgE to these autoallergens, which provoke a release of proinflammatory mediators from skin mast cells. The classification of ColdU includes typical and atypical subtypes. We know that cold‐induced wheals usually develop on rewarming and resolve within an hour and that anaphylaxis can occur. The diagnosis relies on the patient's history and cold stimulation testing. Additional diagnostic work‐up, including a search for underlying infections, should only be done if indicated by the patient's history. The management of ColdU includes cold avoidance, the regular use of nonsedating antihistamines and the off‐label use of omalizumab. However, many questions regarding ColdU remain unanswered. Here, we review what is known about ColdU, and we present important unanswered questions on the epidemiology, underlying pathomechanisms, clinical heterogeneity and treatment outcomes. Our aim is to guide future efforts that will close these knowledge gaps and advance the management of ColdU.