Evidence for histamine release in chronic inducible urticaria – A systematic review

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.

Delayed Pressure Urticaria Associated With Altitude Chamber Training Responsive to Cyclosporine and Omalizumab

Delayed pressure urticaria (DPU) is a subset of chronic inducible urticaria. It is characterized by the formation of wheals anytime between 30 minutes and 24 hours after stimulus exposure of localized pressure application. In this case report, we discuss a military flight crew member with no significant past medical history who developed DPU following rapid decompression in an altitude chamber. The chamber training included an uneventful ascent to 45,000 feet, higher than he had been previously, and a rapid decompression. About 16 hours later, he developed pruritic swelling of his hands and feet, along with diffuse deep nodular swelling, erythematous plaques, and erythematous nodules. His DPU was refractory to monotherapy treatment with antihistamines, and he continued to develop lesions in weight-bearing areas. Control of symptoms was achieved through combination treatment of a second-generation antihistamine, a leukotriene receptor antagonist, and an immunosuppressant (cyclosporine). His waiver to return to flight status was denied while on cyclosporine. He was transitioned to a monoclonal antibody that binds free immunoglobin E (omalizumab) with resolution of symptoms and was cleared to return to active duty.

Targeting histamine receptor 4 in cholinergic urticaria with izuforant (LEO 152020): results from a phase IIa randomized double-blind placebo-controlled multicentre crossover trial

BACKGROUND

Cholinergic urticaria (CholU) is a common subtype of chronic inducible urticaria, where signs and symptoms (e.g. pruritic wheals and angioedema) are triggered by sweating due to physical exercise, passive warming and by other sweat-inducing situations. While guidelines recommend treatment with second-generation H1 antihistamines, approximately 90% of patients report uncontrolled disease. Targeting the histamine 4 receptor (H4R) has shown promise in preclinical/clinical studies of allergic/inflammatory diseases. Izuforant (LEO 152020) is a selective oral H4R antagonist with expected dual antipruritic and anti-inflammatory effects.

OBJECTIVES

To assess the effects of izuforant in adults with CholU, a common type of chronic urticaria driven by histamine and characterized by high skin levels of H4R expression.

METHODS

This was a phase IIa randomized double-blind placebo-controlled multicentre crossover trial where patients with CholU with an inadequate response to ≥ 1 standard dose of H1 antihistamine received izuforant 100 mg twice daily or placebo (EUCTR2020-004961-38-DE; NCT04853992). The primary endpoint was change from baseline in Urticaria Activity Score. Exploratory endpoints included CholU activity score over 7 days, urticaria control test, Physician Global Assessment, patient global assessment of severity (PGA-S), provocation tests, Dermatology Life Quality Index and CholU quality of life (CholU-QoL). Pharmacokinetic and pharmacodynamic parameters, and serum biomarkers were assessed, as well as safety and tolerability.

RESULTS

Nineteen patients were randomized and included in the full analysis set; 18 completed treatment [mean (SD) age 29.5 (9.8) years; mean (SD) CholU duration 8.0 (6.3) years]. The primary and most of prespecified exploratory endpoints were not met; there were significant improvements in PGA-S for izuforant vs. placebo (P = 0.02), and nonsignificant improvements for other endpoints in quality of life and histamine skin prick test. All adverse events (AEs) experienced with izuforant were considered mild. The most frequently reported (> 1 patient) were nausea (three patients) and upper abdominal pain (two patients), occurring more frequently with izuforant vs. placebo (one patient each). There were no treatment-related serious AEs and no patient receiving izuforant discontinued the study. Treatment with izuforant did not cause downregulation of H4R.

CONCLUSIONS

This is the first study to explore the role of H4R as a therapeutic target in urticaria. Targeting H4R with izuforant was well tolerated but did not demonstrate significant improvements vs. placebo in the primary endpoint and all but one prespecified exploratory endpoint in CholU.

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.

Clinical efficacy of Zhiyang Xiaozhen granules combined with second-generation antihistamine in the treatment of chronic urticaria

OBJECTIVES

Chronic urticaria presents a chronic process of recurrent attacks, and its first-line treatment is second-generation antihistamine with limited treatment options. The efficacy of antihistamine varies among individuals and cannot meet the needs of all patients. This study aims to explore the clinical efficacy and safety of Zhiyang Xiaozhen granules combined with antihistamine in the treatment of chronic urticaria patients.

METHODS

We retrospectively analyzed the clinical data of patients with chronic urticaria who visited the Xiangya Hospital of Central South University from April 2020 to March 2021. The patients who received conventional second-generation antihistamine treatment were selected as a control group, while the patients who received combined treatment with Zhiyang Xiaozhen granules on the basis of conventional second-generation antihistamine treatment were selected as an observation group. The differences in the Weekly Urticaria Activity Score (UAS7) and Dermatology Life Quality Index (DLQI) between the 2 groups before and 4 weeks after treatment were compared. The Symptom Score Reduce Index (SSRI) was used to evaluate and compare the efficacy of the 2 treatment regimens.

RESULTS

After 4 weeks of treatment, the UAS7 levels in both groups were significantly reduced (P=0.001 and P<0.001, respectively). The effective rates of the control group and the observation group were 61.11% and 59.38%, respectively when converting UAS7 to SSRI for efficacy evaluation, and there was no statistically significant difference in efficacy between the 2 groups (P>0.05); however, when converting DLQI to SSRI for efficacy evaluation, the effective rates of the control group and the observation group were 33.33% and 46.88%, respectively, and the difference in efficacy between the 2 groups was statistically significant (P<0.001). There were 3 patients with adverse drug reactions related to drowsiness in both groups.

CONCLUSIONS

The combination of Zhiyang Xiaozhen granules and second-generation antihistamine can effectively improve disease activity in patients with chronic urticaria, and the improvement in quality of life is better than that with the second-generation antihistamine alone.

Research progress in the pathogenesis of chronic urticaria

Chronic urticaria is very common in clinic, but its pathogenesis is not fully elucidated. Most patients can't find the exact cause, resulting in misdiagnosis or delayed treatment. Previous studies have found that mast cell activation is the central link in the pathogenesis of chronic urticaria. Genetics, autoimmune, coagulation disorders, and infection may also be involved in the pathophysiological process of chronic urticaria. With the deepening of research, more immune and non-immune mechanisms have been gradually revealed in the pathogenesis of chronic urticaria, such as the interaction of immune cells in the microenvironment of urticaria, intestinal flora and metabolism, neuroimmunity, environmental factors and hormones. Clarifying the pathogenesis of chronic urticaria will help to find more treatment targets and provide more diversified ideas for clinical diagnosis and treatment.

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.

Chronic urticaria and the pathogenic role of mast cells

The signs and symptoms of chronic urticaria (CU) are caused by the activation and degranulation of skin mast cells (MCs). Recent studies have added to our understanding of how and why skin MCs are involved and different in CU. Also, novel and relevant mechanisms of MC activation in CU have been identified and characterized. Finally, the use of MC-targeted and MC mediator-specific treatments has helped to better define the role of the skin environment, the contribution of specific MC mediators, and the relevance of MC crosstalk with other cells in the pathogenesis of CU. Here, we review these recent findings and their impact on our understanding of CU, with a focus on chronic spontaneous urticaria (CSU). Also, we highlight open questions, issues of controversy, and unmet needs, and we suggest what studies should be performed moving forward.

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.