Psychological Stress and Chronic Urticaria: A Neuro-immuno-cutaneous Crosstalk. A Systematic Review of the Existing Evidence

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.

Role of stress in skin diseases: A neuroendocrine-immune interaction view

Psychological stress is a crucial factor in the development of many skin diseases, and the stigma caused by skin disorders may further increase the psychological burden, forming a vicious cycle of psychological stress leading to skin diseases. Therefore, understanding the relationship between stress and skin diseases is necessary. The skin, as the vital interface with the external environment, possesses its own complex immune system, and the neuroendocrine system plays a central role in the stress response of the body. Stress-induced alterations in the immune system can also disrupt the delicate balance of immune cells and inflammatory mediators in the skin, leading to immune dysregulation and increased susceptibility to various skin diseases. Stress can also affect the skin barrier function, impair wound healing, and promote the release of pro-inflammatory cytokines, thereby exacerbating existing skin diseases such as psoriasis, atopic dermatitis, acne, and urticaria. In the present review, we explored the intricate relationship between stress and skin diseases from a neuroendocrine-immune interaction perspective. We explored the occurrence and development of skin diseases in the context of stress, the stress models for skin diseases, the impact of stress on skin function and diseases, and relevant epidemiological studies and clinical trials. Understanding the relationship between stress and skin diseases from a neuroendocrine-immune interaction perspective provides a comprehensive framework for targeted interventions and new insights into the diagnosis and treatment of skin diseases.

Ccrl2-centred immune-related lncRNA-mRNA co-expression network revealed the local skin immune activation mechanism of moxibustion on adjuvant arthritis mice

BACKGROUND

Moxibustion is an important external therapy of traditional medicine that operates on some acupoints on the skin and is usually used for immune-related diseases. However, whether the immune function of the skin, especially the immune-related lncRNAs, contributes to the mechanism of moxibustion remains unclear.

METHODS

Adjuvant arthritis (AA) was induced by injection of Complete Freund's adjuvant (CFA) into the right hind paw of mice. Moxibustion was administered on the Zusanli (ST36) acupoint for 3 weeks. The alteration of foot volume and cytokine concentration in serum was used to evaluate the anti-inflammation effect of moxibustion. CD83 expression in the local skin of ST36 was measured by immunofluorescence staining. Transcriptome RNA sequencing (RNA-seq) and lncRNA-mRNA network analysis were performed to construct a moxibustion-induced Immune-related lncRNA-mRNA co-expression network. qRT-PCR was used to validate the RNA-seq data.

RESULTS

Moxibustion at ST36 relieved the foot swelling, decreased the TNF-α and IL-1β concentrations in serum, and obviously increased the CD83 expression at the local skin of ST36. A total of 548 differentially expressed lncRNAs and 520 linked mRNAs were screened out. The significantly and predominately enriched Go term was inflammatory and immune response, and the main pathways related to inflammatory and immune responses include Toll-like receptor, cytokine-cytokine receptor, and MAPK signaling. The immune-related lncRNA-mRNA co-expression network showed 88 lncRNAs and 36 mRNAs, and Ccrl2 is the central hub of this network.

CONCLUSION

Local immune activation is significantly triggered by moxibustion in ST36 of AA mice. The Ccrl2-centered immune-related lncRNA-mRNA co-expression network would be a promising target for decoding the mechanism of moxibustion for immune-related diseases.

Neuro-Immuno-Psychological Aspects of Chronic Urticaria

Urticaria is a condition characterized by the development of itchy wheals (hives), angioedema, or both. The pathophysiology of chronic spontaneous urticaria (CSU) is still poorly understood. It is suggested that there is no dominant and independent mechanism of CSU; however, there are different immunological and non-immunological abnormalities that act simultaneously or/and follow each other resulting in clinical symptoms. The latest hypothesis points out that mast cells (MCs) to be activated via autoantibodies in autoallergic or autoimmune mechanism mediators released from degranulated MCs are responsible for the vasoactive and neurospecific effect in CSU. According to many clinical observations, it is suggested that psychological stress can be both a triggering factor in the onset of CSU and a modulating one in the course of the disease and therapy effectiveness. Of importance, the mechanistic background of the psychological stress response in the skin has not yet been fully elucidated. However, of note, a variety of inflammatory mediators, neuropeptides, and neurotransmitters facilitate this phenomenon. This review presents recent findings on the neuro-immuno-psychological aspects of CSU, highlighting an emerging role of neuro-immune interactions. It also points out the usefulness of psychological tools employment for the baseline diagnosis of perceived stress level and the presence of its symptoms. Furthermore, it proposes the implementation of non-invasive interventions to reduce psychological stress and anxiety. A bio-psycho-social approach including psychological support and patient education seems to be as important as traditional pharmacotherapy for CSU. It facilitates the effective control of active disease and a prolonged remission time in this disease.

Psychiatric comorbidities in children and adolescents with chronic urticaria

BACKGROUND

Chronic urticaria (CU) has been shown to impact patients' quality of life negatively and may coexist with psychiatric disorders. We systematically reviewed the published evidence of comorbid psychiatric disorders in children and adolescents with CU.

METHODS

A systematic review of studies published until February 2022 in PubMed, Google Scholar, and Scopus was performed. An a priori set of inclusion criteria was predefined for the studies to be included: (1) clear distinction between urticaria and other allergies; (2) precise distinction between acute and CU; (3) participants younger than 18 years old, exclusively; (4) use of appropriate standardized questionnaires, psychometric tools, and standard diagnostic nomenclature for the mental health and behavioral disorders diagnosis; and (5) manuscripts written or published in the English language.

RESULTS

Our search identified 582 potentially relevant papers. Only eight of them satisfied the inclusion criteria. Quantitative meta-analysis was not deemed appropriate, given the lack of relevant randomized control trials, the small number of relevant shortlisted, the small sample size of the patients included in each study, and the remarkable heterogeneity of the studies' protocols.

CONCLUSIONS

The included studies suggest an increased incidence of psychopathology among children and adolescents with CU as opposed to healthy age-matched individuals, but the data are scarce. Further research is required to clarify whether psychopathology is just a comorbid entity, the cause, or the consequence of CU. Meanwhile an interdisciplinary collaboration between allergists/dermatologists and psychiatrists is expected to substantially minimize CU burden and improve patients' quality of life.

Urticaria and Angioedema: Understanding Complex Pathomechanisms to Facilitate Patient Communication, Disease Management, and Future Treatment

Chronic spontaneous urticaria (CSU) is primarily a T2-dominant disease with a complex genetic background. Skin mast cell activation can be induced not only via the IgE-FcεRI axis but also from several other distinct mechanisms, molecules, and receptors involved in CSU onset, persistence, and exacerbation. These include autoallergy, autoimmunity, central or peripheral neuroimmune dysregulation, activation of both extrinsic and intrinsic coagulation pathways, and microbial infections. Besides mast cells, recent reports suggest the active and direct involvement of basophils and eosinophils. Several biological characteristics or biomarkers have been linked with CSU's known endotypes and may help forecast therapeutic responses. The introduction of biologic therapy for CSU has been a major advance in the last 10 years. The cornerstone of angioedema (AE) pathogenesis is increased vascular permeability and plasma leakage into the deeper dermis and subcutis, either mediated by histamine or bradykinin (BK). C1-inhibitor deficiency, hereditary or acquired, is the primary cause of BK-mediated AE due to increased plasma BK concentration. Other complex conditions have been identified, with some likely involving contact system dysregulation and other putative mechanisms related to vascular endothelial dysfunction. The approval of multiple hereditary-AE-specific therapies for both prevention and acute attacks has revolutionized treatment of this disease. Any new knowledge of the pathogenesis of CSU and AE offers the opportunity to improve patient information, physician-patient communication, prediction of therapeutic responses, selection of precise tailor-made treatment for each patient, and exploration of novel treatment options for those who do not achieve disease control with current medications.

Validation of a novel method of ultraviolet-induced cutaneous inflammation and its associations with anhedonia

Affective immunology of the skin is a growing area; however, established protocols for measuring individual differences in cutaneous inflammation are lacking. To address this, we present a preliminary validation of Precision Implementation of Minimal Erythema Dose (PI-MED) testing as a method for measuring cutaneous inflammation. PI-MED is a recently adapted protocol, optimized for reproducibility and individual differences research, that uses ultraviolet (UV) light to evoke cutaneous erythema, or inflammatory skin reddening. PI-MED's novel UV dosage schedule produces standardized erythema responses across different skin pigmentation types and shows strong internal consistency within person and good test-retest reliability across 8-10 weeks. In line with predictions, increased PI-MED erythema was associated with heightened anhedonia, across several measures, beyond influences of non-affective covariates. While future work should further refine the dosage schedule for the lightest and darkest skin types, overall, evidence supports PI-MED as a protocol for inducing and measuring individual differences in cutaneous inflammation. Further, PI-MED-induced erythema can expand psychoneuroimmunology research by offering a complementary assessment for general inflammatory tone. This work adds to a growing body of evidence demonstrating a distinct relationship between inflammation and anhedonia.

Navigating patients with atopic dermatitis or chronic spontaneous urticaria during the COVID-19 pandemic

A rapid spread of different strains of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented pandemic. Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, the medical body has encountered major obstacles concerning disease management at different levels. Even though patients infected with this virus mainly present with respiratory symptoms, it has been associated with a plethora of well-documented cutaneous manifestations in the literature. However, little investigations have been conducted concerning COVID-19 and its impact on skin disorders mediated by type 2 inflammation leaving multiple dermatologists and other specialists perplexed by the lack of clinical guidelines or pathways. This review focuses on the effects of this pandemic in patients with skin disorders mediated by type 2 inflammation, specifically atopic dermatitis and chronic spontaneous urticaria. In addition, it will provide clinicians a guide on treatment and vaccination considerations for this stated set of patients.

Further Understanding of Neuro-Immune Interactions in Allergy: Implications in Pathophysiology and Role in Disease Progression

The complicated interaction between the central and the autonomic (sympathetic, parasympathetic, and enteric) nervous systems on the one hand and the immune system and its components, on the other hand, seems to substantially contribute to allergy pathophysiology, uncovering an under-recognized association that could have diagnostic and therapeutic potentials. Neurons connect directly with and regulate the function of many immune cells, including mast cells, the cells that have a leading role in allergic disorders. Proinflammatory mediators such as cytokines, neurotrophins, chemokines, and neuropeptides are released by immune cells, which stimulate sensory neurons. The release of neurotransmitters and neuropeptides caused by the activation of these neurons directly impacts the functional activity of immune cells and vice versa, playing a decisive role in this communication. Successful application of Pavlovian conditioning in allergic disorders supports the existence of a psychoneuroimmunological interplay in classical allergic hypersensitivity reactions. Activation of neuronal homeostatic reflexes, like sneezing in allergic rhinitis, coughing in allergic asthma, and vomiting in food allergy, offers additional evidence of a neuroimmunological interaction that aims to maintain homeostasis. Dysregulation of this interaction may cause overstimulation of the immune system that will produce profound symptoms and exaggerated hemodynamic responses that will lead to severe allergic pathophysiological events, including anaphylaxis. In this article, we have systematically reviewed and discussed the evidence regarding the role of the neuro-immune interactions in common allergic clinical modalities like allergic rhinitis, chronic rhinosinusitis, allergic asthma, food allergy, atopic dermatitis, and urticaria. It is essential to understand unknown – to most of the immunology and allergy experts – neurological networks that not only physiologically cooperate with the immune system to regulate homeostasis but also pathogenetically interact with more or less known immunological pathways, contribute to what is known as neuroimmunological inflammation, and shift homeostasis to instability and disease clinical expression. This understanding will provide recognition of new allergic phenotypes/endotypes and directions to focus on specialized treatments, as the era of personalized patient-centered medicine, is hastening apace.

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.

Impact of coronavirus disease 2019 on the mental health of university students in Sichuan Province, China: An online cross-sectional study

Coronavirus disease 2019 is an emerging public health problem threatening not only the life but also the normal psychology of people. University students' mental health is the focus in the field of higher education. The coronavirus disease 2019 pandemic has brought into attention the mental health problems of this vulnerable group. The aim of this study was to assess the impact of coronavirus disease 2019 on the mental health of university students in Sichuan Province, China. We conducted a cross-sectional study from April 2020 to May 2020. The participants responded to an online questionnaire that included informed consent, basic information, 20-item Self Reporting Questionnaire (SRQ-20), and Self-Rating Anxiety Scale (SAS). We received 521 effective responses. The results included the following: 19.0% of respondents reported distress, and 31.5%, 8.1%, and 5.8% of them reported mild, moderate, and severe anxiety, respectively; respondents aged ≤ 22 years, medical students, and those who were in general health reported more distress than others; and medical students and those who paid more attention to pandemic information reported more anxiety than others. Findings suggest that the mental health of university students should be monitored during pandemic, especially for younger students, medical students, students in general health status, and those who paid too much attention to the news of the pandemic. Due to the limited sample representativeness, we must be cautious when generalizing these findings to other regions of China or other countries.

Psychological burden of COVID-19 on mild and moderate chronic spontaneous urticaria

Background: The impact of coronavirus disease 2019 (COVID-19) related mental health status on chronic spontaneous urticaria (CSU) has not been addressed before. Objective: The aim of this study was to evaluate the depression, anxiety and stress levels, and the fear of COVID-19 in patients with mild-to-moderate CSU and to determine their impact on urticaria activity during the pandemic. Methods: A total of 509 patients with mild-to-moderate CSU were prospectively evaluated with validated scales, the Depression Anxiety Stress Scale 21 (DASS-21) and the Fear of COVID-19 Scale (FCV-19S) during the lockdown period (LP) and the return to normal period (RTNP). CSU activity was determined with the urticaria activity score summed over 7 days (UAS7) and medication scores (MS). UAS7 and MS before the pandemic were retrospectively collected from medical records. Results: The median UAS7 and MS were both significantly higher in the LP than in the median of related scores during the prepandemic period (p < 0.0001) and the RTNP (p < 0.0001). The mean FCV-19S and DASS-21 scores were both significantly higher in the LP than in the RTNP (p < 0.0001). The FCV-19S and the DASS-21 anxiety and stress subscales were significantly higher in women. The UAS7s were positively correlated with the FCV-19S and depression, anxiety, and stress subscale scores. Conclusion: Fear of COVID-19, anxiety, depression, and stress during the COVID-19 pandemic, especially when strict isolation measures are taken, have a significant impact on mental health and urticaria activity in patients with mild-to-moderate CSU, even though they are not infected. Psychological support for patients with CSU seems to be important to control disease activity during the pandemic.