Cold urticaria - What we know and what we do not know

Key differences between chronic inducible and spontaneous urticaria

Introduction

The latest international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for urticaria recommends limited laboratory testing for chronic spontaneous urticaria (CSU) and selective testing for only certain chronic inducible urticaria (CIndU) subtypes, though the rationale for these recommendations is poorly explained. This study aimed to improve the understanding of CIndU subtypes by comprehensively comparing their demographic, clinical, and laboratory characteristics with those of the better-characterized CSU.

Methods

We conducted a retrospective analysis of 567 patients (median age 41 years, 67% female) diagnosed with CSU, symptomatic dermographism (SD), cold urticaria (ColdU), cholinergic urticaria (CholU), and delayed pressure urticaria (DPU).

Results

Our findings revealed that patients with SD, ColdU, and CholU had lower levels of C-reactive protein (CRP), higher total serum immunoglobulin E (IgE) levels, and higher basophil counts compared to CSU patients. These subtypes also had distinct demographic and clinical features, such as a younger age of onset and a longer disease duration. In contrast, patients with DPU had significantly higher CRP levels and neutrophil counts compared to those with CSU.

Discussion

These findings highlight the heterogeneity among chronic urticaria subtypes, suggesting that a tailored approach to laboratory testing may be more effective. The distinct immunological and clinical features observed in CIndU subtypes suggest a need for subtype-specific diagnostic and therapeutic guidelines.

Chronic Inducible Urticaria

Chronic inducible urticaria (CIndU) is characterized by the appearance of hives (urticaria) and/or angioedema in response to specific triggers or stimuli. For accurate diagnosis, anamnesis-driven specific, and if available, standardized trigger testings, as well as patient reported outcomes, should be applied. The currently recommended treatment algorithm is the same as for chronic spontaneous urticaria but is largely off-label for CIndU. New, and possibly more disease-specific, treatment options are needed for CIndU patients, who are often severely impacted by their disease. Several clinical trials are currently ongoing.

The Definition, Classification, and History of Urticaria

The term "urticaria" was first introduced by William Cullen in the eighteenth century. Urticaria is a common mast cell-mediated cutaneous disease presenting with pruritic wheals, angioedema, or both. It is classified as acute (≤6 weeks) or chronic (>6 weeks) and as spontaneous (no definite triggers) or inducible (definite and subtype-specific triggers). The international urticaria guideline on the definition, classification, diagnosis, and management of urticaria is revised every 4 years. The global network of Urticaria Centers of Reference and Excellence, the biggest and most active consortium of urticaria specialists, offers physicians and patients several research, educational, and digital care initiatives.

Cold Injury

Cold injury has been documented for centuries and remains a concern for military personnel, winter recreationalists, and urban homeless populations. Treatment advances in the last decades have included thrombolytic and prostaglandin therapies however the mainstay remains early recognition and rapid rewarming. This chapter focuses on frostbite, with a brief overview of other cold related conditions.

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.

Cold urticaria in tropics: A clinico-epidemiological study from North India

Background Cold urticaria (ColdU) is classified as a subtype of chronic inducible urticaria characterised by recurring pruritic wheals and/or angioedema upon exposure to cold stimuli. However, very limited data is available on ColdU specifically among Indians. Objectives The aim of this study was to describe the clinico-epidemiological characteristics and treatment response in North Indian patients diagnosed with ColdU. Materials and Methods The clinical records of patients diagnosed with ColdU past 5 years (January 2018 to December 2022) were retrospectively reviewed. Data including patient demographics, clinical manifestations, comorbidities, laboratory findings, and treatment response were collected and analysed. Results Among the 1780 urticaria patients included in our study, only 15 cases of cold-induced urticaria were identified. ColdU was classified as typical in all but three patients. The mean age of affected individuals was 36 ± 18 years (20-65 years) and eight patients (53.3%) were males. Mean disease duration at presentation was 18 ± 27 months (3 months-4 years). Two patients experienced cold-induced angioedema and one patient had hypotensive episodes following cold exposure. Twelve patients demonstrated positive results in the ice cube provocation test. Of 15, only 6 (40%) achieved complete control of symptoms with standard dosing of second generation anti-histamines while six patients (40%) required titration to higher doses and three patients (20%) were initiated on cyclosporine therapy, resulting in remission. Limitations Retrospective study design and possibility of selection bias. Conclusion Due to India's predominantly tropical climate, ColdU prevails at lower levels compared to the western regions. ColdU is likely underdiagnosed in India, possibly dismissed as chronic spontaneous urticaria. The management of ColdU involves a combination of protective measures against cold exposure and the use of anti-histamines to control disease activity. This retrospective study provides valuable insights into the clinico-epidemiological characteristics and treatment response of north Indian patients with ColdU.

Moniezia benedeni infection increases IgE+ cells in sheep (Ovis aries) small intestine

The concentration of immunoglobulin (Ig) E is the lowest among serum Igs, but it can induces type I hypersensitivity and plays an important role in anti-parasitic infection. The present study aimed to explore the residence characteristics of IgE+ cells in the sheep small intestine and the impact of Moniezia benedeni infection on them. The recombinant plasmids pET-28a-IgE were constructed and induced and expressed in Escherichia coli. BL21 (DE3). The rabbit anti-sheep IgE polyclonal antibody was prepared using the obtained recombinant protein as antigen. Finally, the levels of IgE+ cells in the small intestine of healthy (Control group) and naturally M. benedeni-infected (Infected group) sheep were detected analyzed. The results showed that the rabbit anti-sheep IgE polyclonal antibody with good immunogenicity (titer = 1: 128000) could specifically bind to the heavy chain of natural sheep IgE. In the Control group, the IgE+ cells were mainly distributed in lamina propria of the small intestine, and the densities were significantly decreased from duodenum to ileum (P<0.05), with respective values of (4.28 cells / 104 μm2, 1.80 cells / 104 μm2, and 1.44 cells / 104 μm2 in duodenum, jejunum, and ileum. In the Infected group, IgE+ cells density were 6.26 cells / 104 μm2, 3.01 cells / 104 μm2, and 2.09 cells / 104 μm2 in duodenum, jejunum and ileum respectively, which were significantly higher in all segments compared to the Control group (P<0.05), increasing by 46.26%, 67.22% and 45.14%, respectively. In addition, compared with the Control group, the IgE protein levels were significantly increased in all intestinal segments of the Infected group (P<0.01), however, there was no significant differences among the different intestinal segments within the same group (P>0.05). The results demonstrated that M. benedeni infection could significantly increase the content of IgE and the distribution density of its secreting cells in sheep small intestine. The intestinal mucosal immune system of sheep presented obvious specificity against M. benedeni infection. This lays a good foundation for further exploring molecular mechanisms of the intestinal mucosal immune system monitoring and responding to M. benedeni infection.

Immunopathogenesis of urticaria: a clinical perspective on histamine and cytokine involvement

BACKGROUND

Urticaria is a clinical condition characterized by the appearance of wheals (hives), angioedema, or both. Over the last several decades, a better understanding of the mechanisms at play in the immunopathogenesis of urticaria has underscored the existence of numerous urticaria subtypes. Separating the different kinds of urticaria explicitly helps find the best detection method for the management of this skin disorder. Subtypes of urticaria also include both spontaneous and physical types. The conventional ones include spontaneous urticaria, constituting both acute and chronic urticaria. Therefore, a broad and effective therapy is essential for the diagnosis and treatment of urticaria.

METHODS

To understand the immunopathogenesis of urticaria, various databases, including PubMed, Scopus, and Web of Science, were used to retrieve original articles and reviews related to urticaria. While information on several clinical trials were obtained from clinicaltrials.gov database.

RESULTS

This article highlights the immunopathogenesis involved in the intricate interaction between cellular infiltration, immune reactions, coagulation cascades, and autoantibodies that underlie urticaria's pathophysiology.

CONCLUSION

The recent progress in understanding urticaria can help to understand the intricate characteristics in the immunopathogenesis of urticaria and could play a beneficial role in the management of urticaria.

The Spectrum of Cutaneous Manifestations in Lupus Erythematosus: A Comprehensive Review

Lupus erythematosus (LE) is an autoimmune inflammatory disease with complex etiology. LE may present as a systemic disorder affecting multiple organs or be limited solely to the skin. Cutaneous LE (CLE) manifests with a wide range of skin lesions divided into acute, subacute and chronic subtypes. Despite classic forms of CLE, such as malar rash or discoid LE, little-known variants may occur, for instance hypertrophic LE, chilblain LE and lupus panniculitis. There are also numerous non-specific manifestations including vascular abnormalities, alopecia, pigmentation and nail abnormalities or rheumatoid nodules. Particular cutaneous manifestations correlate with disease activity and thus have great diagnostic value. However, diversity of the clinical picture and resemblance to certain entities delay making an accurate diagnosis The aim of this review is to discuss the variety of cutaneous manifestations and indicate the clinical features of particular CLE types which facilitate differential diagnosis with other dermatoses. Although in diagnostically difficult cases histopathological examination plays a key role in the differential diagnosis of LE, quick and accurate diagnosis ensures adequate therapy implementation and high quality of life for patients. Cooperation between physicians of various specialties is therefore crucial in the management of patients with uncommon and photosensitive skin lesions.

Cold-induced anaphylaxis triggered by drinking cold water

Cold urticaria is an inducible urticaria in which hives and angioedema appear after exposure to cold. The symptoms of cold urticaria often are limited to hives/angioedema. However, in up to 20% of cases, cold exposure may trigger anaphylaxis. We report the case of an 11-year-old boy previously diagnosed with chronic spontaneous urticaria who developed facial swelling, itchy hives, difficulty in breathing, vomiting and abdominal pain within 5 minutes of drinking cold water. He received a standard dose of non-sedating second-generation antihistamines at home. He was observed in the emergency room for 2 hours and discharged with an epinephrin autoinjector. During the subsequent outpatient clinic visit, an ice cube test was performed which confirmed the new diagnosis of comorbid cold-induced chronic urticaria. On further questioning, the parents reported occurrence of hives following swimming in the swimming pool. Cold-induced urticaria should be suspected in cases of anaphylaxis associated with cold exposure. Patients with chronic forms of urticaria who present with new anaphylaxis should be assessed for a potential concomitant cold-induced form.

Cold urticaria as a complication of cryotherapy in the treatment of viral warts

Cryotherapy with liquid nitrogen has been established as the first-line treatment for pediatric patients with viral warts. Cold-induced urticaria (CU) is a rare skin reaction triggered by cold stimuli. We present the case of a pediatric patient with viral warts who developed CU after receiving cryotherapy.

A comparative analysis of chronic inducible urticaria in 423 patients: Clinical and laboratory features and comorbid conditions

BACKGROUND

Chronic inducible urticaria (CIndU) is a subtype of chronic urticaria (CU) which require specific physical or non-physical triggers to occur. They may be isolated or may coexist with chronic spontaneous urticaria (CSU). Despite their frequent appearance in dermatology clinics, there is scarce information on the distinguishing features among the most common subtypes of CIndU as well as isolated CIndU versus CSU plus CIndU.

OBJECTIVES

To compare clinical and laboratory characteristics, and comorbid conditions among the most common CIndU types and isolated CIndU versus CSU plus CIndU.

METHODS

We retrospectively analysed CIndU patients and compared patients' demographic, clinical and laboratory characteristics across isolated CIndU, CSU plus CIndU, symptomatic dermographism (SD), cold urticaria (ColdU) and cholinergic urticaria (ChoU).

RESULTS

A total of 423 patients (~70% isolated CIndU, ~30% CSU plus CIndU, ~5% mixed CIndU subtypes) were included in the study. The most frequent CIndU subtypes were SD (68.6%; 290/423), ColdU (11.4%; 48/423) and ChoU (10.9%; 46/423). Isolated CIndU patients were younger than CSU plus CIndU (33.74 ± 12.72 vs. 37.06 ± 11.84, p = 0.010). Angioedema, emergency referrals, need for systemic steroids, comorbid systemic disorders were more frequent and baseline urticaria control test scores were lower in CSU plus CIndU patients (vs. CIndU, p < 0.001, p = 0.008, p < 0.001, p = 0.031, p = 0.036, respectively). Among CIndU subtypes, ChoU patients were younger (24.9 ± 12.2 vs. 34.47 ± 12.12 vs. 31.38 ± 14.95; p < 0.001) and had male predominance (p < 0.001) while SD patients had no angioedema (p < 0.001) and had higher frequency of increased total IgE levels (p = 0.006).

CONCLUSIONS

Isolated CIndU and CSU plus CIndU seems to be different endotypes of CU where CSU plus CIndU presents a more severe and refractory course. There are distinctive features of each CIndU subtype. These suggest involvement of different pathomechanistic pathways in these subtypes that need to be clarified in future studies.

Approach to Idiopathic Anaphylaxis in Adolescents

Anaphylaxis is a potentially-life threatening condition. Adolescents are particularly vulnerable due to increased risk-taking behaviors, poor disease management, and minimized perception of risk. Although most anaphylaxis can be attributed to food, drug, or venom allergy via a detailed history and confirmatory studies, in nearly 1 in 5 cases, the cause may not be obvious. Clinical differentials including rare allergens, cofactors, mast-cell disorders, and mimic disorders can increase the likelihood of discovering of the cause of anaphylaxis.

Cold-Induced Urticaria in a Paediatric Patient: A Case Report and Literature Review

Acquired cold-induced urticaria is a rare form of physical urticaria, especially in children. The variety of clinical presentations and the low estimated prevalence contribute to its underdiagnosis. Given the associated risk of anaphylaxis, it is crucial to alert clinicians to the different forms of presentation, diagnosis, and treatment. Starting with a case report of acquired cold-induced urticaria in a previously healthy nine-year-old boy, the authors then review the literature about acquired cold-induced urticaria and discuss the diagnostic exams and disease management.

Recent updates in urticaria

Urticaria is a skin-condition characterized by sudden-onset pruritic wheals with/without angioedema. Urticaria can be acute or chronic. Chronic urticaria may be spontaneous or inducible, based on absence/presence of specific triggers. Chronic spontaneous urticaria is most frequent (∼80%). Urticaria is primarily a mast-cell mediated histaminergic-disorder. Recently, other inflammatory cells and pro-inflammatory cytokines have been implicated. Deeper understanding has unmasked two endotypes - IgE-mediated type I autoimmunity/autoallergy and IgG-mediated type IIb autoimmunity. Current treatment recommendation involving second-generation H1-antihistamines, omalizumab and cyclosporine is effective in 60-80% patients. So, newer treatment options are being explored based on emerging targets. Despite being non-lethal, urticaria considerably impairs patient's quality-of-life and may be associated with extra-cutaneous comorbidities. Several "patient reported outcome measures" have been proposed to evaluate disease-activity, impact and control, for effective treatment modulation till complete disease control. This review discusses the current understanding about urticaria and its future directions, to facilitate optimum evidenced-based care.

Cold-induced urticaria in children: A multicenter, retrospective cohort study

Background: Studies of cold-induced urticaria (ColdU) in pediatric patients are limited and not well characterized. Objective: The objective of the study was to investigate the characteristics of ColdU in children. Methods: A multicenter, retrospective chart review was performed in children ages ≤18 years diagnosed with ColdU at 11 pediatric allergy and immunology centers in Turkey between September 1, 2010, and August 31, 2022. Results: A total of 83 children with ColdU were included, 54.2% were girls, and the mean age of symptom onset was 8.8 years. The median duration of ColdU at the time of diagnosis was significantly higher in the girls than in the boys (1.0 years [0.0-13.8 years] versus 0.3 years [0.0-15.0 years]; p = 0.007). All the patients underwent an ice cube test, and 71.1% were found positive (typical ColdU). The mean ± standard deviation age of onset was significantly higher in the patients with typical ColdU versus atypical patients (9.4 ± 4.5 years versus 7.3 ± 4.5 years; p = 0.041). Swimming alone and in combination with the wind were significantly the most reported triggers in patients with cold-induced anaphylaxis (ColdA) when compared with patients with ColdU and with nonanaphylactic symptoms (70.0% versus 28.9% [p = 0.022], and 50.0% versus 4.1% [p < 0.001], respectively). Only patients with other chronic urticaria were found to be associated with the development of typical ColdU (p = 0.036). The median total serum immunoglobulin E (IgE) was significantly higher in typical ColdU than in atypical patients (72.5 IU/mL [3.86 - 2500 IU/mL] versus 30.0 IU/mL [0.83 - 1215 IU/mL]; p = 0.007); however, total serum IgE differences were not found to affect ColdU resolution between the two groups (p = 0.204). The resolution was documented in 30.4%. Conclusion: Those who were boys and had a positive ice cube test result could have an association with earlier onset of ColdU. Those swimming alone on a windy day were at highest risk for ColdA. It is still unclear what characteristics are associated with the resolution of ColdU, and this warrants further investigation.

Cold Anaphylaxis in Children: Italian Case Series and Review of the Literature

Chronic urticaria (CU) is one of the most common skin disorders worldwide. Among the inducible subgroup of CU, cold urticaria (ColdU) can affect both children and adults and is the only type associated with the risk of anaphylaxis without cofactors. In the scientific literature, data about cold anaphylaxis (ColdA) are poor, especially at pediatric age, and little is known about risk factors associated with the onset of systemic reactions and about the criteria for prescribing adrenaline auto-injectors (AAIs) in these patients. We describe the clinical characteristics and management of a case series of 21 patients with a history of ColdA, and we compare them with the pediatric case reports and case series published so far. On the basis of the scientific literature and of our case series of patients, we suggest that AAI should be prescribed to all high-risk patients: those with urticaria caused by cold-water immersion, oropharyngeal reactions, and with a previous history of systemic symptoms or anaphylaxis.

A Fully Self-Powered Wearable Leg Movement Sensing System for Human Health Monitoring

Energy-autonomous wearable human activity monitoring is imperative for daily healthcare, benefiting from long-term sustainable uses. Herein, a fully self-powered wearable system, enabling real-time monitoring and assessments of human multimodal health parameters including knee joint movement, metabolic energy, locomotion speed, and skin temperature, which are fully self-powered by highly-efficient flexible thermoelectric generators (f-TEGs) is proposed and developed. The wearable system is composed of f-TEGs, fabric strain sensors, ultra-low-power edge computing, and Bluetooth. The f-TEGs worn on the leg not only harvest energy from body heat and supply power sustainably for the whole monitoring system, but also serve as zero-power motion sensors to detect limb movement and skin temperature. The fabric strain sensor made by printing PEDOT: PSS on pre-stretched nylon fiber-wrapped rubber band enables high-fidelity and ultralow-power measurements on highly-dynamic knee movements. Edge computing is elaborately designed to estimate multimodal health parameters including time-varying metabolic energy in real-time, which are wirelessly transmitted via Bluetooth. The whole monitoring system is operated automatically and intelligently, works sustainably in both static and dynamic states, and is fully self-powered by the f-TEGs.

Potential Therapeutic Approaches for Chronic Urticaria: Beyond H1-Antihistamines and Biologics

Chronic urticaria is a disease that can significantly impact a patient's quality of life and ability to function. There are effective treatment options, such as nonsedating antihistamines or biologics, but some patients do not respond to these therapies, or the therapies are not available or affordable to all patients. This review aims to summarize potential treatment strategies for patients (1) who do not respond to antihistamines and (2) cannot readily access or do not respond to biologics. The review emphasizes the importance of sound clinical practice, including correct diagnosis of chronic urticaria phenotypes, treatment of associated comorbidities, and consideration of add-on pharmacological and nonpharmacological approaches. Although some treatments may lack high-quality evidence, they may still be justifiable in certain cases, provided that there is shared decision-making, regular reassessment, and early recognition of adverse events.

Inhibition of interleukin-1 with rilonacept is not effective in cold urticaria-Results of a randomized, placebo-controlled study

BACKGROUND

Cold urticaria (ColdU) is characterized by pruritic wheals following exposure of the skin to cold. Many patients show insufficient response to antihistamines, the first line treatment. Based on the high efficacy of interleukin-1(IL-1)-inhibition in cold-induced urticarial autoinflammatory diseases, we assessed the effects of rilonacept, an IL-1 inhibitor, in ColdU patients unresponsive to standard treatment.

METHODS

In this randomized, double-blind, placebo-controlled two-center study, we included 20 patients with ColdU. In the first part, patients received 320 mg rilonacept or placebo (1:1) followed by weekly doses of 160 mg rilonacept or placebo for 6 weeks. In the second part, all patients received weekly 160 mg or 320 mg rilonacept for 6 weeks, open-label. The primary endpoint was change in critical temperature threshold (CTT). Secondary endpoints included changes in quality of life impairment (Dermatology Life Quality Index, DLQI), differences of inflammatory mediators upon cold provocation and safety assessment over the study period.

RESULTS

Baseline mean CTTs were 20.2°C (placebo) and 17.3°C (rilonacept). Mean CTTs did not change significantly during the 6-week double-blind treatment (placebo - 0.45°C; rilonacept +0.89°C). IL-6, IL-18 and HSP-70 blood levels showed interindividual variability without significant changes during hand cold water bath provocation in placebo- or rilonacept-treated patients. In contrast, DLQI significantly improved in the rilonacept (mean DLQI reduction of 3.8; p = 0.002) but not in the placebo group (mean DLQI reduction of 0). Comparing baseline with the rilonacept open-label treatment, there were no changes in CTTs or DLQI scores.

CONCLUSION

IL-1 inhibition with rilonacept did not improve ColdU, but demonstrated a good safety profile.

CLINICAL TRIAL REGISTRATION

EudraCT number: 2012-005726-30.

CLINICALTRIALS

gov identifier: NCT02171416.

Urticaria

Urticaria is an inflammatory skin disorder that affects up to 20% of the world population at some point during their life. It presents with wheals, angioedema or both due to activation and degranulation of skin mast cells and the release of histamine and other mediators. Most cases of urticaria are acute urticaria, which lasts ≤6 weeks and can be associated with infections or intake of drugs or foods. Chronic urticaria (CU) is either spontaneous or inducible, lasts >6 weeks and persists for >1 year in most patients. CU greatly affects patient quality of life, and is linked to psychiatric comorbidities and high healthcare costs. In contrast to chronic spontaneous urticaria (CSU), chronic inducible urticaria (CIndU) has definite and subtype-specific triggers that induce signs and symptoms. The pathogenesis of CSU consists of several interlinked events involving autoantibodies, complement and coagulation. The diagnosis of urticaria is clinical, but several tests can be performed to exclude differential diagnoses and identify underlying causes in CSU or triggers in CIndU. Current urticaria treatment aims at complete response, with a stepwise approach using second-generation H1 antihistamines, omalizumab and cyclosporine. Novel treatment approaches centre on targeting mediators, signalling pathways and receptors of mast cells and other immune cells. Further research should focus on defining disease endotypes and their biomarkers, identifying new treatment targets and developing improved therapies.

Discrepancies in the management of acquired cold contact urticaria: Results of a French-speaking urticaria experts questionnaire survey

Acquired cold contact urticaria (ACU) is a putatively serious condition, because of the risk of anaphylactic shock whenever patients are massively exposed to cold atmosphere/water, raising the question of the prescription of an “emergency kit” with oral antihistamines and epinephrine auto-injector. We performed an online survey to evaluate how French-speaking urticaria experts manage ACU. According to the 2016 consensus recommendations on chronic inducible urticarias, all the participants perform at least 1 of the available provocation tests and 84.2%, 77.8%, and 88.9% prescribe on-label use of second generation anti-H1 antihistamines (2GAH1) as a first line treatment, updosed 2GAH1 as a second line treatment, and omalizumab as a third line treatment, respectively. Interestingly, 44.4% of the practitioners always prescribe a continuous background treatment, versus 11.1% prescribing only on-demand therapy. Also, 11.7% of participants always prescribe an epinephrine auto-injector, 70.6% sometimes do, and 17.6% never do. Finally, 89.5% authorize swimming under strict conditions but 36.8% and 68.4% contra-indicate other water sports and occupational cold exposure, respectively.

Activation of CD81+ skin ILC2s by cold-sensing TRPM8+ neuron-derived signals maintains cutaneous thermal homeostasis

As the outermost barrier tissue of the body, the skin harbors a large number of innate lymphoid cells (ILCs) that help maintain local homeostasis in the face of changing environments. How skin-resident ILCs are regulated and function in local homeostatic maintenance is poorly understood. We here report the discovery of a cold-sensing neuron-initiated pathway that activates skin group 2 ILCs (ILC2s) to help maintain thermal homeostasis. In stearoyl-CoA desaturase 1 (SCD1) knockout mice whose skin is defective in heat maintenance, chronic cold stress induced excessive activation of CCR10^-CD81⁺ST2⁺ skin ILC2s and associated inflammation. Mechanistically, stimulation of the cold-sensing receptor TRPM8 expressed in sensory neurons of the skin led to increased production of IL-18, which, in turn, activated skin ILC2s to promote thermogenesis. Our findings reveal a neuroimmune link that regulates activation of skin ILC2s to support thermal homeostasis and promotes skin inflammation after hyperactivation.

Development of the Cold Urticaria Activity Score

BACKGROUND

Cold urticaria (ColdU) is a form of inducible urticaria where cold induces wheals and/or angioedema. The burden of disease is high and linked to trigger thresholds, exposure, and avoidance. There are presently no validated patient-reported outcome measures (PROMs) to assess and monitor disease activity. Our objective was to develop a disease-specific activity score for ColdU that is easy to administer and evaluate.

METHODS

A Cold Urticaria Activity Score (ColdUAS) questionnaire was developed, directed by PROM developing guidelines. After the generation of a conceptional framework, the item generation phase included the literature research on ColdU signs and symptoms and on comparable tools for similar diseases and 47 ColdU patient interviews. Subsequently, an impact analysis for content validity was performed. The final selection of items underwent expert review for face validity and cognitive debriefing.

RESULTS

The ColdUAS, a self-administered questionnaire for the prospective assessment of disease activity in patients with ColdU, consists of 4 items: 1. the frequency and severity of the signs (wheals and/or angioedema), 2. the frequency and severity of the symptoms (e.g., itch and burn), 3. the exposure to specific triggers, and 4. the avoidance of these triggers. The recall period for each item is the last 24 h.

CONCLUSIONS

The ColdUAS is the first disease-specific PROM to assess ColdU disease activity. It may help to better assess patients' disease status in routine clinical practice as well as in clinical trials. Anchor-based approaches are currently used to validate the ColdUAS.

Cold urticaria in a pediatric cohort: Clinical characteristics, management, and natural history

BACKGROUND

Cold urticaria (coldU) is associated with substantial morbidity and risk of fatality. Data on coldU in children are sparse. We aimed to evaluate the clinical characteristics, management, risk of associated anaphylaxis, and resolution rate of coldU in a pediatric cohort. Additionally, we sought to compare these metrics to children with chronic spontaneous urticaria (CSU).

METHODS

We prospectively enrolled children with coldU from 2013-2021 in a cohort study at the Montreal Children's Hospital and an affiliated allergy clinic. Data for comparison with participants with solely CSU were extracted from a previous study. Data on demographics, comorbidities, severity of presentation, management, and laboratory values were collected at study entry. Patients were contacted yearly to assess for resolution.

RESULTS

Fifty-two children with cold urticaria were recruited, 51.9% were female and the median age of symptom onset was 9.5 years. Most patients were managed with second-generation H1-antihistamines (sgAHs). Well-controlled disease on sgAHs was negatively associated with concomitant CSU (adjusted odds ratio (aOR) = 0.69 [95%CI: 0.53, 0.92]). Elevated eosinophils were associated with cold-induced anaphylaxis (coldA; aOR = 1.38 [95%CI: 1.04, 1.83]), which occurred in 17.3% of patients. The resolution rate of coldU was 4.8 per 100 patient-years, which was lower than that of CSU (adjusted hazard ratio = 0.43 [95%CI: 0.21, 0.89], p < 10^-2 ).

CONCLUSION

Pediatric coldU bears a substantial risk of anaphylaxis and a low-resolution rate. Absolute eosinophil count and co-existing CSU may be useful predictive factors.

Chronic Urticaria: A Swedish Registry-based Cohort Study on Population, Comorbidities and Treatment Characteristics

Swedish databases present unique opportunities to research population data on diseases and treatments. The current study is, to our knowledge, the most comprehensive registry-based study on a chronic urticaria population in Sweden to date. The aim of this study was to describe the chronic urticaria population in Stockholm County regarding epidemiology, demographics, comorbidity, healthcare usage and treatment patterns in relation to current international guidelines. Real-world data were extracted between 2013 and 2019, yielding 10,642 adult patients. Study period prevalence of chronic urticaria was 0.53%, the mean annual incidence was approximately 0.08%, and 68% of patients were female. Regarding diagnosis, 58% were first diagnosed in primary care, approximately 50% were diagnosed before the age of 40 years. Regarding type of urticaria, 89% had chronic spontaneous urticaria, 11% had chronic inducible urticaria, and 5% of patients with chronic urticaria had coexisting angioedema. Common coexisting diagnoses were, for example, asthma, allergy, psychiatric and behavioural disorders and cardiometabolic disorders. Treatment patterns generally followed guidelines, yet data indicated that guidelines were not fully implemented, especially in primary care.

Risk factors for systemic reactions in typical cold urticaria: Results from the COLD-CE study

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.

Prevalence, Management, and Anaphylaxis Risk of Cold Urticaria: A Systematic Review and Meta-Analysis

BACKGROUND

Cold urticaria is a subtype of chronic inducible urticaria (CIndU) associated with significant morbidity and a risk for anaphylaxis. Few studies have assessed the prevalence, management, and prevalence of associated anaphylaxis of cold urticaria.

OBJECTIVES

To evaluate the prevalence of cold urticaria among CIndU and chronic urticaria (CU) cases, to assess the management of cold urticaria, and to determine the prevalence of associated anaphylaxis.

METHODS

We searched PubMed and EMBASE for studies pertaining to cold urticaria and/or CIndU published in the past 10 years. We conducted meta-analyses to evaluate the prevalence of cold urticaria among CIndU and CU cases, the management of cold urticaria with H1-antihistamines and omalizumab, and the prevalence of associated anaphylaxis.

RESULTS

Twenty-two studies were included in the systematic review and 14 in the meta-analysis. The pooled prevalence of cold urticaria among patients with CU and CIndU was 7.62% (95% confidence interval [CI], 3.45% to 15.99%; I² = 98%) and 26.10% (95% CI, 14.17% to 43.05%; I² = 97%), respectively. Cold urticaria was managed by H1-antihistamines in 95.67% (95% CI, 92.47% to 97.54%; I² = 38%) of patients and omalizumab in 5.95% (95% CI , 2.55% to 13.27%; I² = 83%) of patients. The pooled prevalence of anaphylaxis among patients with cold urticaria was 21.49% (95% CI, 15.79% to 28.54%; I² = 69%).

CONCLUSIONS

Cold urticaria constitutes an appreciable proportion of CIndU and CU cases and is predominantly managed with H1-antihistamines; few patients receive omalizumab. Anaphylaxis is common, and an epinephrine autoinjector prescription may be considered.

Chronic Urticaria: Advances in Understanding of the Disease and Clinical Management

Chronic urticaria (CU) is a common skin condition characterized by the recurrence of wheals, with or without angioedema, which lasts for at least 6 weeks. Owing to its pruritus and incurability, this disease adversely affects the patients' physical and mental health and diminishes the quality of life. CU is generally classified into two subtypes based on the relevance of eliciting factors: chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU), the latter of which is further divided into several subtypes. To improve the understanding and clinical management of this highly heterogeneous disorder, the EAACI/GA²LEN/EDF/WAO guideline was developed and published in 2018 based on evidence and expert consensus. The diagnostic and treatment algorithms proposed by the guideline have largely facilitated dermatologists in clinical practice. However, several questions remained unsolved and have been widely investigated in the recent years. First, a better understanding of the association between chronic urticaria and its potential underlying causes or eliciting factors such as autoimmunity, infections, coagulation aberrance, and vitamin D deficiency is warranted. This would lead to updates in the diagnostic and treatment procedures of different subtypes of chronic urticaria. Secondly, treatment for recalcitrant cases, especially those resistant to or intolerant of second-generation antihistamines and (or) omalizumab, calls for novel therapeutic measures or strategies. In the present review, we summarized recent advances in the understanding and management of both CSU and CIndU, with special emphasis on their underlying causes or eliciting factors, pathogenic mechanisms, potential targets for intervention, and advances in treatment strategies.

Topical Vapocoolant-Associated Vaso-occlusive Event in a 10-year-old with Sickle Cell Disease

Vapocoolant sprays are convenient forms of cold temperature analgesia. These sprays may not be suitable for all patients with particular concern for patients with sickle cell disease. To prevent any further cases from occurring, we propose adding a more specific cautionary statement to the manufacturer guidelines. We also hope that medical personnel can help patients with sickle cell avoid topical and environmental cold temperature triggers for sickle vaso-occlusive pain and reduce the suffering in this rare disease.

Cryoglobulins, Cryofibrinogens, and Cold Agglutinins in Cold Urticaria: Literature Review, Retrospective Patient Analysis, and Observational Study in 49 Patients

Introduction

Cryoproteins, such as cryoglobulins, cryofibrinogens and cold agglutinins, precipitate at low temperatures or agglutinate erythrocytes and dissolve again when warmed. Their pathogenetic and diagnostic importance in cold urticaria (ColdU) is unclear. In this study, we aimed to characterize the prevalence of cryoproteins in patients with ColdU.

Methods

We conducted 3 analyses: i) a systematic review and meta-analysis of published data using an adapted version of the Joanna Briggs Institute's critical appraisal tool for case series, ii) a retrospective analysis of 293 ColdU patients treated at our Urticaria Center of Reference and Excellence (UCARE) from 2014 to 2019, and iii) a prospective observational study, from July 2019 to July 2020, with 49 ColdU patients as defined by the EAACI/GA2LEN/EDF/UNEV consensus recommendations.

Results

Our systematic review identified 14 relevant studies with a total of 1151 ColdU patients. The meta-analyses showed that 3.0% (19/628), 1.1% (4/357) and 0.7% (2/283) of patients had elevated levels of cryoglobulins, cryofibrinogens and cold agglutinins, respectively. Our retrospective analyses showed that cryoproteins were assessed in 4.1% (12/293) of ColdU patients. None of 9 ColdU patients had cryoglobulins, and one of 5 had cold agglutinins. In our prospective study, none of our patients had detectable cryoglobulins (0/48) or cryofibrinogens (0/48), but 4.3% (2/46) of patients had cold agglutinins (without any known underlying autoimmune or hematological disorder).

Conclusion

Our investigation suggests that only very few ColdU patients exhibit cryoproteins and that the pathogenesis of ColdU is driven by other mechanisms, which remain to be identified and characterized in detail.

Cold Agglutinins and Cryoglobulins Associate With Clinical and Laboratory Parameters of Cold Urticaria

Mast cell-activating signals in cold urticaria are not yet well defined and are likely to be heterogeneous. Cold agglutinins and cryoglobulins have been described as factors possibly associated with cold urticaria, but their relevance has not been explained. We performed a single-center prospective cohort study of 35 cold urticaria patients. Cold agglutinin and cryoglobulin test results, demographics, detailed history data, cold stimulation test results, complete blood count values, C-reactive protein, total immunoglobulin E levels, and basal serum tryptase levels were analyzed. Forty six percent (n = 16) of 35 tested patients had a positive cold agglutinin test and 27% (n = 9) of 33 tested patients had a positive cryoglobulin test. Cold agglutinin positive patients, when compared to cold agglutinin negative ones, were mainly female (P = 0.030). No gender-association was found for cryoglobulins. A positive cold agglutinin test, but not a positive cryoglobulin test, was associated with a higher rate of reactions triggered by cold ambient air (P = 0.009) or immersion in cold water (P = 0.041), and aggravated by increased summer humidity (P = 0.007). Additionally, patients with a positive cold agglutinin test had a higher frequency of angioedema triggered by ingestion of cold foods or drinks (P = 0.043), and lower disease control based on Urticaria Control Test (P = 0.023). Cold agglutinin levels correlated with erythrocyte counts (r = −0.372, P = 0.028) and monocyte counts (r = −0.425, P = 0.011). Cryoglobulin concentrations correlated with basal serum tryptase levels (r = 0.733, P = 0.025) and cold urticaria duration (r = 0.683, P = 0.042). Results of our study suggest that cold agglutinins and cryoglobulins, in a subpopulation of cold urticaria patients, are linked to the course and possibly the pathogenesis of their disease.