Cholinergic Urticaria and Exercise-Induced Anaphylaxis

New insights into chronic inducible urticaria

PURPOSE OF REVIEW

Chronic inducible urticaria (CIndU) is a group of long-persisting and challenging to manage diseases, characterized by recurrent wheals and angioedema induced by definite triggers. In this review, we address recent findings on CIndU pathogenesis, diagnosis as well as its treatment, and we discuss novel potential targets that may lead to the development of more effective therapies for CIndU patients.

RECENT ADVANCES

Meaningful advances in the understanding of its pathogenesis have been reported in the last decades. Novel CIndU-specific patient-reported outcome measures enable a closer and better evaluation of patients. CIndU is a hard-to-treat disease that highly impairs quality of life (QoL) of affected patients. Provocation tests allow to diagnose CIndU subtypes. The only licensed and recommended treatment for CIndU are second generation non-sedating H1-antihistamines, which lack efficacy in many cases. Omalizumab off-label use has been assessed in all types of CIndU with overall good outcomes. Promising emerging therapies currently assessed in chronic spontaneous urticaria are paving the path for novel treatments for CIndU.

The many faces of pediatric urticaria

Urticaria is a common disease that can affect individuals of all age groups, with approximately one-quarter of the population experiencing it at least once in their lifetime. Lesions characterized by erythema and itchy hives can appear anywhere on the body. These can vary in size ranging from millimeters to centimeters, and typically clear within 24 h. About 40% of patients with urticaria have accompanying angioedema, which involves localized deep tissue swelling. Urticaria usually occurs spontaneously and is classified into acute and chronic forms, with the latter referring to a condition that lasts for more than 6 weeks. The prevalence of chronic urticaria in the general population ranges from 0.5% to 5%, and it can either be inducible or spontaneous. The most common form of pediatric urticaria is acute and is usually self-limiting. However, a broad differential diagnosis should be considered in children with urticaria, particularly if they also have accompanying systemic complaints. Differential diagnoses of pediatric urticaria include chronic spontaneous urticaria, chronic inducible urticaria, serum sickness-like reaction, urticarial vasculitis, and mast cell disorders. Conditions that can mimic urticaria, including but not limited to cryopyrinopathies, hyper IgD syndrome, Periodic Fever, Aphthous Stomatitis, Pharyngitis and Adenitis (PFAPA), Tumor Necrosis Factor Receptor Associated Periodic Syndrome (TRAPs), and Schnitzler syndrome should also be considered. The many faces of pediatric urticaria can be both easy and confusing. A pragmatic approach relies on clinical foresight and understanding the various forms of urticaria and their potential mimickers. This approach can pave the way for an accurate and optimized diagnostic approach in children with urticaria.

Equine allergic skin diseases: Clinical consensus guidelines of the World Association for Veterinary Dermatology

BACKGROUND

Allergic skin diseases are common in horses worldwide. The most common causes are insect bites and environmental allergens.

OBJECTIVES

To review the current literature and provide consensus on pathogenesis, diagnosis, treatment and prevention.

MATERIALS AND METHODS

The authors reviewed the literature up to November 2022. Results were presented at North America Veterinary Dermatology Forum (2021) and European Veterinary Dermatology Congress (2021). The report was available to member organisations of the World Association for Veterinary Dermatology for feedback.

CONCLUSIONS AND CLINICAL RELEVANCE

Insect bite hypersensitivity (IBH) is the best characterised allergic skin disease. An immunoglobulin (Ig)E response against Culicoides salivary antigens is widely documented. Genetics and environmental factors play important roles. Tests with high sensitivity and specificity are lacking, and diagnosis of IBH is based on clinical signs, seasonality and response to insect control. Eosinophils, interleukin (IL)-5 and IL-31 are explored as therapeutic targets. Presently, the most effective treatment is insect avoidance. Existing evidence does not support allergen-specific immunotherapy (ASIT) using commercially available extracts of Culicoides. Hypersensitivity to environmental allergens (atopic dermatitis) is the next most common allergy. A role for IgE is supported by serological investigation, skin test studies and positive response to ASIT. Prospective, controlled, randomised studies are limited, and treatment relies largely on glucocorticoids, antihistamines and ASIT based on retrospective studies. Foods are known triggers for urticaria, yet their role in pruritic dermatitis is unknown. Recurrent urticaria is common in horses, yet our understanding is limited and focussed on IgE and T-helper 2 cell response. Prospective, controlled studies on treatments for urticaria are lacking. Glucocorticoids and antihistamines are primary reported treatments.

Prevalence of Chronic Inducible Urticaria in Elderly Patients

BACKGROUND

No data currently exist regarding the epidemiology of chronic inducible urticarias (CIndUs) in the ≥65-year-old population.

OBJECTIVE

The study aimed to determine the prevalence of CIndUs among elderly patients affected by chronic urticaria (CU).

METHODS

The medical records of all patients referred to us with a diagnosis of CU from January 2008 to September 2020 were retrospectively reviewed, and the patients with CIndUs were identified. The subjects aged 65 years or above were included in the study.

RESULTS

The number of patients aged 65 years or above was 153 out of 1970 subjects affected by CU (7.77%; 92 females (60.13%); mean age 70.96 ± 4.22). Out of 153, 26 patients (16.99%; 20 females (76.9%); mean age 71.23 ± 2.6 years) were diagnosed with CIndUs. Most subjects (25/26; 96.15%) suffered from physical urticarias. Symptomatic dermographism was the most frequent, affecting 65.38% (17/26) of our patients, followed by cold urticaria (6/26 (23.08%) cases).

CONCLUSION

Our data seem to indicate that CIndUs may also affect the elderly, although it occurs less frequently in aging patients than in lower age groups.

Idiopathic anaphylaxis: What you do not know may hurt you

Idiopathic anaphylaxis (IA), like immunologic and nonimmunologic anaphylaxis, is a life-threatening, sometimes fatal allergic disease. Although the priority is immediate recognition and initiation of treatment, long-term care planning is important to help reduce anxiety and promote healthy growth and development. Learning to recognize, manage, and stabilize the child is an essential part of improving the family dynamics. Despite advancements in the management of anaphylaxis, research has shown a need for continued patient education and training to improve timely recognition and treatment. This article focuses on elucidating the clinical presentation, theories of pathogenesis, and diagnosis, treatment, and management of IA.

How to Approach Chronic Inducible Urticaria

Chronic inducible urticaria (CIndU) is a group of chronic urticarias characterized by the appearance of recurrent wheals, recurrent angioedema or both, as a response to specific triggers. CIndU includes both physical (symptomatic dermographism, cold and heat urticaria, delayed pressure urticaria, solar urticaria, and vibratory urticaria) and nonphysical urticarias (cholinergic urticaria, contact and aquagenic urticaria). Here, we review the different forms of CIndU with an emphasis on symptomatic dermographism, cold urticaria, cholinergic urticaria, and delayed pressure urticaria. We discuss the clinical features, the diagnostic workup including provocation and threshold testing, and available treatment options.

Checklist for a complete chronic urticaria medical history: an easy tool

BACKGROUND

Existing guidelines do not offer a quick, efficient alternative to the patient's recollection of relevant clinical features during anamnesis and physical examination for chronic urticaria (CU). This study aimed to identify specific items reflecting the main characteristics of CU that should be included in a comprehensive medical history for patients with CU. We also aimed to clarify possible eliciting factors for CU to support accurate diagnosis of the disease.

METHODS

A panel of postgraduate dermatologists conducted a literature search for relevant studies on CU using Medline, the Cochrane database, and PubMed.

RESULTS

We identified82 articles from which we drew a collection of items to inform development of an easy-to-use checklist and collection of items that should be included in a correct medical history. The final version of the checklist included42 items across two areas: essential clues for anamnesis and diagnosis of CU; and typical symptoms/parameters or characteristics according to subtype, etiology, and laboratory findings. Items included time of disease onset; duration, shape, size, color, and distribution of wheals; associated angioedema; atopy; and triggering factors.

CONCLUSIONS

Our guide provides an easy-to-use tool to support clinicians to focus, orient themselves, and save time in medical consultations for CU, allowing better diagnosis and management of this disease.

Diagnosis of exercise-induced anaphylaxis: current insights

Exercise-induced anaphylaxis (EIAn) is defined as the occurrence of anaphylactic symptoms (skin, respiratory, gastrointestinal, and cardiovascular symptoms) after physical activity. In about a third of cases, cofactors, such as food intake, temperature (warm or cold), and drugs (especially nonsteroidal anti-inflammatory drugs) can be identified. When the associated cofactor is food ingestion, the correct diagnosis is food-dependent EIAn (FDEIAn). The literature describes numerous reports of FDEIAn after intake of very different foods, from vegetables and nuts to meats and seafood. One of the best-characterized types of FDEIAn is that due to ω5-gliadin of wheat, though cases of FDEIAn after wheat ingestion by sensitization to wheat lipid transfer protien (LTP) are described. Some pathophysiological mechanisms underlying EIAn have been hypothesized, such as increase/alteration in gastrointestinal permeability, alteration of tissue transglutaminase promoting IgE cross-linking, enhanced expression of cytokines, redistribution of blood during physical exercise leading to altered mast-cell degranulation, and also changes in the acid–base balance. Nevertheless, until now, none of these hypotheses has been validated. The diagnosis of EIAn and FDEIAn is achieved by means of a challenge, with physical exercise alone for EIAn, and with the assumption of the suspected food followed by physical exercise for FDEIAn; in cases of doubtful results, a double-blind placebo-controlled combined food–exercise challenge should be performed. The prevention of this particular kind of anaphylaxis is the avoidance of the specific trigger, ie, physical exercise for EIAn, the assumption of the culprit food before exercise for FDEIAn, and in general the avoidance of the recognized cofactors. Patients must be supplied with an epinephrine autoinjector, as epinephrine has been clearly recognized as the first-line intervention for anaphylaxis.

The definition, diagnostic testing, and management of chronic inducible urticarias - The EAACI/GA(2) LEN/EDF/UNEV consensus recommendations 2016 update and revision

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.

Pathophysiological mechanisms of exercise-induced anaphylaxis: an EAACI position statement

This document is the result of a consensus on the mechanisms of exercise-induced anaphylaxis (EIAn), an unpredictable and potentially fatal syndrome. A multidisciplinary panel of experts including exercise physiologists, allergists, lung physicians, paediatricians and a biostatistician reached the given consensus. Exercise-induced anaphylaxis (EIAn) describes a rare and potentially fatal syndrome in which anaphylaxis occurs in conjunction with exercise. The pathophysiological mechanisms underlying EIAn have not yet been elucidated although a number of hypotheses have been proposed. This review evaluates the validity of each of the popular theories in relation to exercise physiology and immunology. On the basis of this evidence, it is concluded that proposed mechanisms lack validity, and it is recommended that a global research network is developed with a common approach to the diagnosis and treatment of EIAn in order to gain sufficient power for scientific evaluation.