Enhanced P-selectin expression in chronic and dermographic urticaria

Shedding light on dermographism: a narrative review

Dermographism is a common subtype of chronic urticaria. It generally manifests as a linear wheal after scratching or friction, with or without angioedema. The pathophysiology is not clear, but currently, we believe that the stimulation of the skin by mechanical stress leads to the activation of mast cells, which provoke the release of histamine and pro-inflammatory mediators, ultimately forming wheal along the stressed area. The gold standard for diagnosis is a medical history and provocation test or dermatographic test. As one of the subtypes of chronic urticaria, the Urticaria Control Test (UCT), Chronic Urticaria Quality of Life questionnaire (CU-Q2oL), and Dermatology Life Quality Index (DLQI) are also effective tools for evaluating disease control in dermographism patients. In addition to avoiding triggers, nonsedating H1 antihistamines are the first-line medications recommended by EAACI and other guidelines; for those who do not respond to standard doses, the recommended dosage can be increased up to 4 times. When necessary, the off-label use of omalizumab can be considered, and some drugs with potential therapeutic effects are still being explored. However, there is still a lack of biomarkers for predicting disease severity, efficacy, and prognosis. Here, we review what we know about dermographism and some points that need exploration in the future.

Chronic spontaneous urticaria: Evidence of systemic microcirculatory changes

BACKGROUND

Chronic spontaneous urticaria (CSU) is a chronic inflammatory skin disease where activation of endothelial cells (ECs) at sites of skin lesions leads to increased blood flow, leakage of fluid into the skin, cellular infiltration, and vascular remodeling. To understand the disease duration and the sometimes vague systemic symptoms accompanying flares, the objective of this study was to examine if CSU comes with systemic vascular changes at the microcirculatory level.

METHODS

We investigated CSU patients (n = 49) and healthy controls (HCs, n = 44) for microcirculatory differences by nailfold videocapillaroscopy (NVC) and for blood levels of the soluble EC biomarkers serum vascular endothelial growth factor (VEGF), soluble E-selectin, and stem cell factor (SCF). Patients were also assessed for clinical characteristics, disease activity, and markers of autoimmune CSU (aiCSU).

RESULTS

CSU patients had significantly lower capillary density, more capillary malformations, and more irregular capillary dilations than HCs on NVC. Serum levels of VEGF, soluble E selectin and SCF were similar in CSU patients and HCs. CSU patients with higher VEGF levels had significantly more abnormal capillaries. Patients with markers of aiCSU, that is, low IgE levels or increased anti-TPO levels, had significantly more capillaries and less capillary dilations than those without.

CONCLUSION

Our results suggest that CSU comes with systemic microcirculatory changes, which may be driven, in part, by VEGF.

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.

Immunological signature of chronic spontaneous urticaria (Review)

Chronic urticaria (CU) is a condition characterized by intensely pruritic, edematous, erythematous papules lasting for more than 6 weeks. Over half of the cases have concomitant swelling of deeper tissues, known as angioedema. The socio-economic burden of the disease is significant. Unfortunately, patients with severe CU, refractory to conventional treatment, have limited and expensive therapeutic options. The pathogenesis of CU is not yet completely understood. Therefore, elucidating the pathophysiological mechanisms involved would potentially identify new therapeutic targets. It has been accepted in recent years that mast cells and their activation, followed by excessive degranulation represent the key pathophysiological events in chronic spontaneous urticaria (CSU). The triggering events and the complexity of the effector mechanisms, however, remain intensely debated topics with conflicting studies. One pathogenetic mechanism incriminated in chronic spontaneous urticaria is the response mediated by the high-affinity receptor for IgE (FcεRI) expressed on mast cells. Increasing recognition of chronic spontaneous urticaria as an autoimmune disease linked to the cytokine-chemokine network imbalance resulting from alteration of innate immune response is another pathogenetic explanation. It is likely that these different pathological mechanisms are more interconnected, both acting synergistically, rather than separately, to produce the clinical expression of CU. The discovery and understanding of pathogenic mechanisms represent the premise for the development of safe and effective immunomodulators and targeted biological treatment for severe, refractory CU.

Markers for the involvement of endothelial cells and the coagulation system in chronic urticaria: A systematic review

Chronic urticaria (CU) is a chronic inflammatory mast cell-driven disorder. Endothelial cells (ECs) contribute importantly to key features of CU. Several markers of EC (dys)function in CU have been reported, but have not yet been systematically reviewed. In this study, we systematically reviewed and categorized all published markers of EC functions in CU through a comprehensive search in Pubmed, The Cochrane Library, Web of Science, and SCOPUS using the following Mesh terms: CU AND pathogenesis AND (vasculopathy OR microangiopathy OR ECs OR marker). In total, 79 articles were selected and the identified biomarkers were categorized according to EC (dys)function in CU. The most frequent and consistently reported upregulated biomarkers in CU skin were adhesion molecules, TF, and P-selectin. The most frequently reported upregulated and reliable biomarkers in sera of CU patients were F1+2 for coagulation cascade involvement, D-dimers for fibrinolysis, and MMP-9 for vascular permeability. Emerging biomarkers described in the selected articles were endostatin, heat shock proteins, cleaved high molecular weight kininogen, and adipokines. This systematic review contributes to the pool of growing evidence for vascular involvement in CU where EC dysfunction is present in different aspects of cell survival, maintenance of vascular structure, and coagulation/fibrinolysis balance.

The Pathogenesis of Chronic Spontaneous Urticaria: The Role of Infiltrating Cells

Chronic spontaneous urticaria is characterized by a perivascular non-necrotizing cellular infiltrate around small venules of the skin. It consists primarily of CD4(+) lymphocytes, a prominence of the T helper (Th)2 subtype but also Th1 cells, with Th17 cell-derived cytokines elevated in plasma. There are also neutrophils, eosinophils, basophils, and monocytes. Chemokines derived from mast cells and activated endothelial cells drive the process. Although the role of the cellular infiltrate has not previously been addressed, each constituent can contribute to the overall pathogenesis. It is of interest that CSU responds to corticosteroid, yet, short-term steroids do not affect autoimmunity or degranulation of mast cells, and act on margination of cells along the endothelium and chemotaxis to enter the surrounding dermis. In this review, we address each cell's contribution to the overall inflammatory response, as it is currently understood, with a view toward development of therapeutic options that impede the function of critical cells and/or their secretory products.

Chronic Spontaneous Urticaria: A Review of Pathological Mechanisms, Diagnosis, Clinical Management, and Treatment

Urticaria is a poorly understood and underestimated clinical condition characterised by the sudden onset of itchy wheals and/or angioedema, which usually resolve within 24 and 72 hours, respectively. It is generally classified as being acute (lasting <6 weeks) or chronic (continuous or intermittent for ≥6 weeks). Chronic urticaria can be further classified as chronic spontaneous urticaria (CSU) and chronic inducible urticaria, appearing in response to specific eliciting factors, such as heat, cold, or sun exposure, or following the application of pressure. Scientific advances have been made in the understanding of pathological mechanisms and treatment, especially associated with CSU. The exact pathological mechanism of how urticaria develops is still not yet fully understood, but the clinical implications on the patients’ quality of life are severe and have been associated with mental disorders and metabolic diseases. The diagnosis of urticaria is based on medical history and clinical manifestations. The treatment pathway begins with the administration of second-generation, nonsedating, nonimpairing histamine 1 receptor antihistamines and, in case of nonresponse, with new-generation biological drugs. The current review presents an update of the pathological mechanisms, diagnosis, clinical management, and treatment of CSU. It also focusses on the future implications of new-generation drugs and their effects on the clinical practice.

Increased Plasma Levels of S100A8, S100A9, and S100A12 in Chronic Spontaneous Urticaria

Background:

Chronic spontaneous urticaria (CSU) is a skin disorder with an important immunologic profile. S100A8, S100A9, and S100A12 are the members of S100 family that have been reported to play important role in autoimmune diseases, but the characteristics of these three S100 members have not been defined in CSU.

Aims:

This study was performed to investigate the levels of these three S100s in patients with CSU and to study whether they were associated with the severity and clinical characteristics of CSU.

Materials and Methods:

The levels of plasma S100A8, S100A9, and S100A12 were measured in 51 CSU patients and 20 healthy controls using enzyme linked immunosorbent assay kits. The values in the patient group and that of the healthy controls were statistically compared. The relationships between the different markers were evaluated by correlation analysis.

Results:

The plasma levels of S100A8, S100A9, and S100A12 were significantly higher in CSU patients than those in controls. Interestingly, the level of S100A12 was significantly correlated with S100A8 and S100A9 in CSU patients (P < 0.05 and P < 0.001, respectively). In addition, S100A8, S100A9, and S100A12 were all significantly inversely correlated with blood basophil percentage.

Conclusions:

Plasma S100A8, S100A9, and S100A12 levels were elevated in CSU patients. They might be useful biomarkers of CSU, with the potential role in the pathogenesis of CSU.

The EAACI/GA²LEN/EDF/WAO guideline for the definition, classification, diagnosis and management of urticaria

This evidence- and consensus-based guideline was developed following the methods recommended by Cochrane and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group. The conference was held on 1 December 2016. It is a joint initiative of the Dermatology Section of the European Academy of Allergology and Clinical Immunology (EAACI), the EU-founded network of excellence, the Global Allergy and Asthma European Network (GA²LEN), the European Dermatology Forum (EDF) and the World Allergy Organization (WAO) with the participation of 48 delegates of 42 national and international societies. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS). Urticaria is a frequent, mast cell-driven disease, presenting with wheals, angioedema, or both. The lifetime prevalence for acute urticaria is approximately 20%. Chronic spontaneous urticaria and other chronic forms of urticaria are disabling, impair quality of life and affect performance at work and school. This guideline covers the definition and classification of urticaria, taking into account the recent progress in identifying its causes, eliciting factors and pathomechanisms. In addition, it outlines evidence-based diagnostic and therapeutic approaches for the different subtypes of urticaria.

The Human Carbonic Anhydrase II in Platelets: An Underestimated Field of Its Activity

Carbonic anhydrases constitute a group of enzymes that catalyse reversible hydration of carbon dioxide leading to the formation of bicarbonate and proton. The platelet carbonic anhydrase II (CAII) was described for the first time in the '80s of the last century. Nevertheless, its direct role in platelet physiology and pathology still remains poorly understood. The modulation of platelet CAII action as a therapeutic approach holds promise as a novel strategy to reduce the impact of cardiovascular diseases. This short review paper summarises the current knowledge regarding the role of human CAII in regulating platelet function. The potential future directions considering this enzyme as a potential drug target and important pathophysiological chain in platelet-related disorders are described.

Consensus Statement for the Diagnosis and Treatment of Urticaria: A 2017 Update

This article is developed by the Skin Allergy Research Society of India for an updated evidence-based consensus statement for the management of urticaria, with a special reference to the Indian context. This guideline includes updated definition, causes, classification, and management of urticaria. Urticaria has a profound impact on the quality of life and causes immense distress to patients, necessitating effective treatment. One approach to manage urticaria is by identification and elimination of the underlying cause(s) and/or eliciting trigger(s) while the second one is by treatment for providing symptomatic relief. This guideline recommends the use of second-generation nonsedating H1-antihistamines as the first-line treatment. The dose can be increased up to four times to meet the expected results. In case patients still do not respond, appropriate treatment options can be selected depending on the associated medical condition, severity of the symptoms, affordability of the drugs, and accessibility of modern biologics such as omalizumab.

Looking forward to new targeted treatments for chronic spontaneous urticaria

The introduction of omalizumab to the management of chronic spontaneous urticaria (CSU) has markedly improved the therapeutic possibilities for both, patients and physicians dealing with this disabling disease. But there is still a hard core of patients who do not tolerate or benefit from existing therapies and who require effective treatment. Novel approaches include the use of currently available drugs off-licence, investigational drugs currently undergoing clinical trials and exploring the potential for therapies directed at pathophysiological targets in CSU. Off-licence uses of currently available drugs include rituximab and tumour necrosis factor inhibitors. Ligelizumab (anti-IgE), canakinumab (anti-IL-1), AZD1981 (a PGD2 receptor antagonist) and GSK 2646264 (a selective Syk inhibitor) are currently in clinical trials for CSU. Examples of drugs that could target potential pathophysiological targets in CSU include substance P antagonists, designed ankyrin repeat proteins, C5a/C5a receptor inhibitors, anti-IL-4, anti-IL-5 and anti-IL-13 and drugs that target inhibitory mast cell receptors. Other mediators and receptors of likely pathogenic relevance should be explored in skin profiling and functional proof of concept studies. The exploration of novel therapeutic targets for their role and relevance in CSU should help to achieve a better understanding of its etiopathogenesis.

Expression of E- and P-selectin in Tumor Necrosis Factor—induced Dermatitis in Dogs

Adhesion molecules on endothelial cells play an important role in leukocyte recruitment in several inflammatory processes. Vascular selectins mediate the initial adhesion of leukocytes to the blood vessel wall during their extravasation into inflamed tissues, and in vitro studies in dogs have shown that selectin expression can be induced by cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1). The objective of this study was to determine whether vascular selectins are induced by cytokines in vivo in a cutaneous model of inflammation in dogs. Skin biopsies were collected from nine dogs at various time points after an intradermal injection of TNF-α (10 ng/site) or phosphate-buffered saline containing 0.1% bovine serum albumin, and immunohistochemistry was performed using anti-P-selectin (MD3) and anti-E-selectin (CL37) monoclonal antibodies. In all animals, TNF-α induced an inflammatory reaction that was maximal at 12 hours and then decreased by 24 and 48 hours. Control skin displayed no expression of E- and P-selectin, whereas TNF-α induced the expression of P-selectin and E-selectin on dermal vessels that was highest at 12 hours and 3 hours, respectively ( P < 0.05). Numerous platelet aggregates recognized by the anti-P-selectin antibody were present in the lumina of vessels and in perivascular tissues. These results demonstrate that TNF-α can induce the expression of P- and E-selectin in vivo in dog skin and suggest that these selectins are involved in leukocyte recruitment in canine dermatitis.

The Role of Platelets in Chronic Urticaria

BACKGROUND

Platelets are implicated in many pathophysiological processes, including inflammation and immunity. Ever-growing evidence suggests the active involvement of platelets in the pathogenesis of various inflammatory disorders, including cutaneous inflammatory diseases. A limited number of studies have investigated the role of platelets in chronic urticaria (CU). In this review, we summarize the current knowledge regarding the role of platelets in chronic spontaneous and inducible urticarias.

METHODS

A literature search was performed using PubMed and Google Scholar, and the references of relevant literature were reviewed.

RESULTS

Overall, in CU patients, conflicting results have been obtained from the assessment of platelet indices, such as mean platelet volume, platelet count and distribution width, as well as markers of platelet aggregation and activation. Nevertheless, a few studies showed significant changes of such parameters in CU patients compared to controls, in apparent correlation with clinical severity, autoreactivity and/or inflammatory status.

CONCLUSIONS

In the absence of definitive conclusions, the pathogenic role of platelets in CU needs to be further explored. Platelets might represent a link between inflammation, coagulation and histamine release in the pathophysiological network of CU.

Elevations in vascular markers and eosinophils in chronic spontaneous urticarial weals with low-level persistence in uninvolved skin

BACKGROUND

In chronic spontaneous urticaria (CSU) mast cell activation together with inflammatory changes in the skin are well documented and may play an important role in mechanisms of tissue oedema.

OBJECTIVES

To confirm and extend these observations by measuring microvascular markers, leucocytes and mast cell numbers in lesional and uninvolved skin and to compare findings with a control group.

METHODS

Paired biopsies (one from 4-8-h spontaneous weals and one from uninvolved skin) were taken from eight patients with CSU and nine control subjects and studied using immunohistochemistry and confocal microscopy using the lectin Ulex europaeus agglutinin 1 (UEA-1).

RESULTS

Lesional skin in CSU contained significantly more CD31+ endothelial cells; CD31+ blood vessels, neutrophils, eosinophils, basophils and macrophages; and CD3+ T cells than nonlesional skin. Increased vascularity was confirmed by confocal imaging using the lectin UEA-1. Uninvolved skin from CSU contained significantly more CD31+ endothelial cells, CD31+ blood vessels and eosinophils compared with the control subjects. There was a threefold increase in mast cell numbers when CSU was compared with controls but no difference was observed between lesional and uninvolved skin.

CONCLUSIONS

Increased vascular markers together with eosinophil and neutrophil infiltration are features of lesional skin in CSU and might contribute to tissue oedema. Eosinophils and microvascular changes persist in uninvolved skin, which, together with increased mast cells, suggests that nonlesional skin is primed for further wealing.

Elevated platelet activation in patients with chronic urticaria: a comparison between aspirin-intolerant and aspirin-tolerant groups

BACKGROUND

Platelets are actively involved in immune inflammatory processes that release inflammatory mediators. Platelet activation has been reported in various inflammatory diseases; however, few studies have described platelet involvement in chronic urticaria (CU).

OBJECTIVE

To investigate platelet-activation markers, namely P2Y12 receptor and P-selectin expression, and soluble P-selectin level in patients with aspirin-intolerant CU (AICU) and aspirin-tolerant CU (ATCU).

METHODS

Forty-eight patients with CU and 25 normal controls were enrolled in this study. Aspirin intolerance in patients with CU was confirmed by an oral provocation test. P2Y12 and P-selectin expressions on platelets were measured using flow cytometry; soluble P-selectin level in plasma was measured by enzyme-linked immunosorbent assay. To study the functional effects of aspirin, platelets were treated with aspirin (2 mmol/L) and the expressions of P2Y12 and P-selectin were compared between the AICU and ATCU groups.

RESULTS

The expression of P2Y12 was significantly higher in patients with CU compared with controls, whereas no significant difference was noted in the expression of P-selectin level. The levels were not significantly different according to urticaria symptom score, symptom control status, and aspirin intolerance. Soluble P-selectin level was significantly higher in the AICU group than in the ATCU group compared with controls. Aspirin did not significantly suppress P2Y12 and P-selectin expressions on platelets in the AICU group, whereas significant suppression was noted in the ATCU group.

CONCLUSION

These findings suggest that increased platelet activation contributes to skin inflammation in patients with AICU and those with ATCU. The functional difference of platelets in response to aspirin may contribute to persistent skin inflammation in patients with AICU.

The EAACI/GA(2) LEN/EDF/WAO Guideline for the definition, classification, diagnosis, and management of urticaria: the 2013 revision and update

This guideline is the result of a systematic literature review using the 'Grading of Recommendations Assessment, Development and Evaluation' (GRADE) methodology and a structured consensus conference held on 28 and 29 November 2012, in Berlin. It is a joint initiative of the Dermatology Section of the European Academy of Allergy and Clinical Immunology (EAACI), the EU-funded network of excellence, the Global Allergy and Asthma European Network (GA(2) LEN), the European Dermatology Forum (EDF), and the World Allergy Organization (WAO) with the participation of delegates of 21 national and international societies. Urticaria is a frequent, mast cell-driven disease, presenting with wheals, angioedema, or both. The life-time prevalence for acute urticaria is approximately 20%. Chronic spontaneous urticaria and other chronic forms of urticaria do not only cause a decrease in quality of life, but also affect performance at work and school and, as such, are members of the group of severe allergic diseases. This guideline covers the definition and classification of urticaria, taking into account the recent progress in identifying its causes, eliciting factors and pathomechanisms. In addition, it outlines evidence-based diagnostic and therapeutic approaches for the different subtypes of urticaria. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS).

Platelet activation in chronic urticaria and its correlation with disease severity

Chronic urticaria (CU) is characterized by the occurrence of wheals lasting for more than 6 weeks. The role of platelet activation in the pathophysiology of this condition has not been clearly studied. We undertook a cross-sectional study among 45 patients with CU and 45 age- and gender-matched healthy controls. The severity of the disease was assessed using the urticaria severity score. The autologous plasma skin test (APST) was done in all cases of CU. The platelet count and indices were estimated by an automated haematological laser optical analyzer. Platelet aggregation and soluble P-selectin levels were estimated in all study participants. It was observed that there was a significantly higher mean platelet volume (MPV) and platelet distribution width (PDW) in patients with CU when compared to controls. Platelet aggregation and soluble P-selectin levels were significantly higher in patients with CU, as compared to controls. Urticaria severity score correlated positively with platelet aggregability and soluble P-selectin levels. APST-positive patients had significantly higher platelet aggregation and higher soluble P-selectin levels, when compared to the APST-negative patients, indicating more platelet activation in the autoimmune group. There is significant platelet activation in patients with CU, especially in those with autoreactivity.

EAACI/GA(2)LEN/EDF/WAO guideline: definition, classification and diagnosis of urticaria

This guideline, together with its sister guideline on the management of urticaria [Zuberbier T, Asero R, Bindslev-Jensen C, Canonica GW, Church MK, Giménez-Arnau AM et al. EAACI/GA(2)LEN/EDF/WAO Guideline: Management of urticaria. Allergy, 2009; 64:1427-1443] is the result of a consensus reached during a panel discussion at the 3rd International Consensus Meeting on Urticaria, Urticaria 2008, a joint initiative of the Dermatology Section of the European Academy of Allergology and Clinical Immunology (EAACI), the EU-funded network of excellence, the Global Allergy and Asthma European Network (GA(2)LEN), the European Dermatology Forum (EDF) and the World Allergy Organization (WAO). Urticaria is a frequent disease. The life-time prevalence for any subtype of urticaria is approximately 20%. Chronic spontaneous urticaria and other chronic forms of urticaria do not only cause a decrease in quality of life, but also affect performance at work and school and, as such, are members of the group of severe allergic diseases. This guideline covers the definition and classification of urticaria, taking into account the recent progress in identifying its causes, eliciting factors, and pathomechanisms. In addition, it outlines evidence-based diagnostic approaches for different subtypes of urticaria. The correct management of urticaria, which is of paramount importance for patients, is very complex and is consequently covered in a separate guideline developed during the same consensus meeting. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS).

Cellular adhesion molecules in chronic urticaria: modulation of serum levels occurs during levocetirizine treatment

BACKGROUND

Some antihistamines are capable of reducing levels of adhesion molecules in wealing tissues of patients with chronic urticaria (CU).

OBJECTIVES

To determine if 6 weeks of therapy with levocetirizine 5 mg once daily would also induce any decrease in serum levels of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, endothelial leucocyte adhesion molecule-1 (ELAM-1) or P-selectin in subjects with CU and chronic autoimmune urticaria.

METHODS

Thirty-six patients with CU (18 with positive and 18 with negative autologous serum skin test) were studied, together with 10 control healthy subjects. All patients received levocetirizine 5 mg daily. Serum soluble cellular adhesion molecule (CAM) levels were determined by immunoenzymatic assay before and after the end of the study period. Disease activity was recorded according to the EAACI/GA(2)LEN/EDF scoring system.

RESULTS

After levocetirizine therapy CAM levels decreased in patients with CU, significantly in the cases of ELAM-1 and P-selectin. Patients' clinical scores improved during regular antihistamine therapy.

CONCLUSIONS

Levocetirizine 5 mg daily demonstrated a broad anti-inflammatory effect in patients with CU. The significant decrease in serum levels of ELAM-1 and P-selectin might reflect the inhibitory activity on neutrophil rolling and extravasation towards inflamed skin.

Urtikaria

A number of recent epidemiologic and experimental studies have enhanced our knowledge of the etiology and pathogenesis of urticaria. In addition, new instruments for diagnosing urticaria variants and for assessing the quality of life in urticaria patients have been developed. Finally, several clinical trials have demonstrated the efficacy of novel treatment approaches for urticaria, while other therapeutic concepts are under development. Here, we provide a brief review of selected findings from these recent reports and a discussion of their relevance for clinical practice.

EAACI/GA2LEN/EDF guideline: definition, classification and diagnosis of urticaria

This guideline is the result of a consensus reached during a panel discussion at the 2nd International Consensus Meeting on Urticaria, Urticaria 2004, a joint initiative of the European Academy of Allergology and Clinical Immunology Dermatology Section and the European Union (EU)-funded network of excellence, GA2LEN. It covers the definition and classification of urticaria, taking into account the recent progress in identifying causes, eliciting factors and pathomechanisms of this disease. We have outlined useful diagnostic approaches for different subtypes of urticaria. This guideline was, in addition, accepted by the European Dermatology Forum (EDF) and was formally approved by the European Union of Medical Specialists (UEMS).

Evaluation of patients with symptomatic dermographism

BACKGROUND

Dermographism or 'simple' dermographism, which has been noted in about 1.5% to 5% of healthy individuals, is regarded as a normal physiological phenomenon. However, in symptomatic dermographism (SD), even light pressure or rubbing from clothes may provoke widespread weal-and-flare reactions with itching and burning. It is one of the dermatologic diseases that negatively impacts quality of life.

OBJECTIVE

We aimed to reveal triggering factors and/or associated clinical conditions in patients with SD.

METHODS

Forty patients (28 women and 12 men) with SD whose ages varied between 7 and 65 (30.3 +/- 10.7) participated in the study. Patients having chronic idiopathic urticaria, other types of physical urticaria and cutaneous/systemic mastocytosis were excluded. The diagnosis of SD was confirmed by stroking the skin of the back with a tongue blade. This procedure elicited within minutes a linear weal with a flare and severe itching. In light of the history, physical examination, skin prick test (SPT) with aeroallergens and laboratory results, a possible relationship of certain triggering factors and/or associated diseases (psychic factors, atopy, thyroid diseases, diabetes, menopause, infectious, systemic or malignant diseases, history of scabies, and history of drug reaction) to SD were investigated.

RESULTS

The duration of SD varied between 10 days and 10 years (mean: 20.8 months). Psychic factors were found to play the initial triggering role in 12 patients (30%). Five patients (12.50%) were atopic, and they had SPT reactivity to house dust mites. Three female patients (7.50%) defined that their complaints began following drug-induced urticarial rash. Two patients (5%) had hyperthyroidism, and one of the patients with SD of 1-month duration had type-II diabetes mellitus. A female patient defined that her complaints began during the onset of menopausal period. SD was observed with scabies in one patient; and after poststreptococcal glomerulonephritis in a 7-year-old girl. No autoimmune, malignant or other systemic diseases were found in patients with SD.

CONCLUSIONS

Contrary to commonly held opinion, SD may be associated with some diseases and/or triggered by some conditions. In this study, a close temporal relationship between the appearance of SD and psychic factors, drug reactions and scabies was documented. The relation between SD and atopy, hyperthyroidism, diabetes mellitus, menopause and glomerulonephritis seemed unclear.

Assessment of platelet activity as expressed by plasma levels of platelet factor 4 and beta-thromboglobulin in patients with chronic idiopathic urticaria

Blood platelet significance in inflammation is recognized but poorly characterized in urticaria. It is known that platelets are activated during inflammatory processes and are involved in modulating inflammatory and immune response via various mediator release. The aim of our study was to investigate the functional state of platelets, expressed by release reaction of C-X-C chemokines such as platelet factor 4 (PF-4) and beta-thromboglobulin (beta-TG) in chronic idiopathic urticaria (CIU). Plasma levels of PF-4 and beta-TG, which are established markers of in vivo platelet activation and which play important role in inflammatory processes, were measured by enzyme-linked immunosorbent assay in 19 patients with CIU and in 25 healthy subjects. Mean plasma PF-4 level in CIU patients and control subjects was 5.01 +/- 1.67 and 4.13 +/- 2.05 IU/ml, respectively, whereas that for beta-TG was 29.3 +/- 14.0 and 25.2 +/- 12.6 IU/ml, respectively. In our small study, there have been no significant differences found between the members of the control and CIU group regarding plasma levels of PF-4 and beta-TG. Further studies should be performed to elucidate whether any systemic platelet activation occurs in CIU.

Urticaria

Urticaria has been known as a disease since antiquity. However, in the last decades an increasing understanding of the mechanisms involved in its pathogenesis has shown the high heterogeneity of different urticaria subtypes. Clear distinction of the subtypes is required not only to choose the correct measures in diagnosis and management, but also to interpret the available data in research. The subtypes can be grouped into spontaneous urticaria, which includes acute urticaria and chronic urticaria, the physical urticarias, special types of urticaria including, e.g. contact urticaria, and diseases related to urticaria for historical reasons, e.g. urticaria pigmentosa. Most urticaria subtypes have a profound impact on the quality of life and effective treatment is thus required in case the diagnostic procedures do not reveal a cause which can be treated. Although, for symptomatic relief, nonsedating H1-antihistamines are the first choice in most subtypes of urticaria, double-blind controlled studies have shown that dosages required may exceed those recommended for other diseases, e.g. allergic rhinitis. Alternative treatments should be reserved for unresponsive patients.

Infiltrating cells and related cytokines in lesional skin of patients with chronic idiopathic urticaria and positive autologous serum skin test

In approximately one-third of patients with chronic idiopathic urticaria (CIU), autoantibodies against the high-affinity IgE receptor and/ or against IgE can be detected and a wheal-and-flare response can be provoked by the intradermal injection of autologous serum (ASST). In this study we aimed to further characterize the inflammatory response observed in the subgroup of CIU patients with positive ASST and serum-evoked histamine-release in vitro from basophils in comparison with unaffected skin and healthy donors. An immunohistochemical analysis of infiltrating cells (CD4, MPO, EG1, EG2, tryptase), cytokines (IL-4, IL-5, IFN-gamma), chemokines and chemokine receptors (IL-8, CCR3, CXCR3), and adhesion molecules (ICAM-1, VCAM-1, ELAM-1) was performed on seven selected patients (four males and three females; median age: 45 years; range: 22-57) and five healthy donors. Cytokine evaluation was also performed in five psoriatic patients to obtain an additional control. In spontaneous wheals we observed an increased number of CD4+ T lymphocytes when compared with the controls, and an increased number of neutrophils and eosinophils, whereas mast cells did not show a significant variation. A significant expression for IL-4 and IL-5 could only be observed in lesional skin, while IFN-gamma showed a slight expression in the same site. Chemokine receptors CCR3 and CXCR3 did not show a defined polarized response in either lesional or unaffected skin. An increased expression of all cellular adhesion molecules (CAMs) studied was detected in spontaneous wheals. The lack of a significant difference in the expression of tryptase + mast cells, T lymphocytes, IL-8, CXCR3 and CCR3, a few CAMs between the lesional and unaffected skin of CIU patients suggests a wide immunological activation that involves not only lesional tissues, but possibly extends to the whole of the skin's immune system.

Evaluation of inflammatory parameters in physical urticarias and effects of an anti-inflammatory/antiallergic treatment

BACKGROUND

Physical urticaria (PU) includes a heterogeneous group of urticarias whose etiopathogenic aspects are still obscure and whose therapeutical management is often difficult. We have previously demonstrated the efficacy of a sequential treatment with nimesulide, a unique nonsteroidal anti-inflammatory drug, and ketotifen in various forms of PU.

METHODS

The expression of some inflammatory parameters was evaluated in 10 patients affected with some forms of PU. In particular, serum levels of interleukin (IL)-4, IL-1beta, tumor necrosis factor (TNF)-alpha, adhesion molecules (sELAM, sICAM-1 and sVCAM), soluble receptors (sIL-2R, sCD30, sCD23) and IgE were assessed. Moreover, the cutaneous expression of IL-1beta, TNF-alpha and ICAM-1 was studied on biopsy specimens taken from nonlesional skin of patients. The same parameters were further evaluated in both skin and serum following treatment with nimesulide and ketotifen, in order to better understand the possible effects of these agents on the inflammatory network of PU.

RESULTS

Before therapy we could detect significantly higher serum levels of IL-1beta and TNF-alpha (P < 0.001) and of circulating adhesion molecules in comparison with controls (sELAM, sICAM: P < 0.001; sVCAM: P < 0.02); after treatment, a significant reduction of each was observed (P < 0.05). Simultaneously, a high expression of IL-1beta, TNF-alpha and ICAM-1 was detected in all skin specimens at the baseline, with a relevant decrease following therapy.

CONCLUSIONS

These results confirm the therapeutical value of treatment with nimesulide and ketotifen in PU and suggest that these agents are able to reduce the release and the expression of some inflammatory molecules that are up-regulated in PU.

Laser-induced weal and flare reactions: clinical aspects and pharmacological modulation

BACKGROUND

Among the adverse effects of cutaneous laser therapy, weal and flare reactions immediately after treatment have received little attention, and the pathomechanisms are unclear.

OBJECTIVES

To study clinical features and possible mechanisms of laser-induced weal and flare reactions in order to identify means of possible therapeutic intervention.

METHODS

Normal skin from the inner arm of 20 volunteers was treated with an argon laser, and the size of weal and flare reactions was measured over a 60-min period. Skin biopsies were taken from four volunteers before and up to 24 h after laser treatment and examined histologically and immunohistologically. Possible underlying mechanisms were also explored using various topical or systemic pharmacological agents.

RESULTS

Wealing was noted in 19 of 20, and flare reactions in all volunteers, with peak values at 15 min. Skin biopsies showed central coagulation of the tissue, cleft formation between epidermis and dermis, normal numbers of morphologically intact mast cells on toluidine blue staining close to the lesion, and only minor upregulation of endothelial and leucocyte adhesion molecules. In agreement with these findings, pretreatment with acetylsalicylic acid, the H1-blocker loratadine and triamcinolone cream was ineffective or resulted in a non-significant reduction of weal and flare reactions. In contrast, local anaesthetics as well as neuropeptide depletion of skin with capsaicin abolished the reactions almost completely.

CONCLUSIONS

Transient weal and flare reactions in response to laser treatment occur in almost all persons and are based primarily on a neurogenic rather than a histamine- or mast cell-dependent mechanism.

Definition, classification, and routine diagnosis of urticaria: a consensus report

Urticaria is a well-known disease entity; however, with an increasing understanding of the molecular mechanisms involved in its pathogenesis, there is also growing evidence for a heterogeneity of urticaria. Currently it is sometimes difficult to compare divergent data reported by different centers researching urticaria due to a lack of precisely described patient populations. A consensus definition and classification of the disease and its subtypes, taking into account new developments, are therefore needed. In addition, this consensus report provides a guideline for diagnostic procedures in different subtypes of urticaria.

Adhesion molecules and cellular infiltrate: histology of urticaria

Urticarial reactions are characterized by dermal capillary dilatation and edema, associated with a variably intense mixed inflammatory infiltrate consisting of neutrophils, eosinophils, T-helper lymphocytes, and activated macrophages. Mast cell numbers are moderately increased by a factor of 2.4, in contrast to mastocytosis where numbers are much higher (5-48-fold increase). In urticarial vasculitis there is in addition endothelial damage, leukocytoclasia, and fibrin and complement deposition. The emigration of leukocytes is regulated by vasoactive and chemotactic mediators released firom mast cells, inducing a sequential upregulation of endothelial adhesion molecules (P-selectin, E-selectin, ICAM-1, and VCAM-1), of beta2-integrins on leukocytes, and of cytokines on endothelial, epithelial, and infiltrating cells. In nonlesional skin, there is also an increase of mast cells and an upregulation of endothelial adhesion molecules, probably due to molecules in the circulation of which P-selectin and TNFalpha have so far been demonstrated. Whereas these data provide a molecular basis for the understanding of variations in mast cell-dependent pathology, they underline the fact that they are not diagnostic for different types of urticaria, except for urticarial vasculitis and mastocytosis.

Anti-FcepsilonRIalpha serum autoantibodies in different subtypes of urticaria

BACKGROUND

In recent years, a histamine-releasing anti-FcepsilonRIalpha autoantibody has been demonstrated in about one-third of patients with chronic urticaria. However, its clinical significance is still unclear. The objective was to detect a possible correlation between the occurrence of the anti-FcepsilonRIalpha autoantibody and the clinical type or cause of urticaria.

METHODS

Sera from 66 consecutively seen in- and outpatients with various types of urticaria and five healthy controls were examined for the presence of anti-FcepsilonRIalpha autoantibodies with a sandwich ELISA technique. In addition, basophil histamine release was studied in 13 autoantibody-positive sera.

RESULTS

Anti-FcepsilonRIalpha autoantibodies were found in 17/48 patients with chronic urticaria, in 2/4 with angioedema, in 1/2 with urticarial vasculitis, and in 2/11 with dermographic urticaria. However, no anti-FcepsilonRIalpha autoantibodies were detected in acute, cold, or delayed-pressure urticaria; in urticaria pigmentosa; or in normal controls. Of all chronic urticaria patients, 22 were classified as idiopathic since no underlying cause could be found. Of this group, seven were seropositive for anti-FcepsilonRIalpha. However, anti-FcepsilonRIalpha was also found in patients who went into remission after treatment of identified causes; namely, in one with type I allergy, one with drug intolerance, one with Helicobacter infection, and six with food intolerance. The autoantibody was also detected in 2/4 patients with associated autoimmune diseases. Functional activity was shown in basophil histamine release in 3/4 autoantibody-positive sera of patients with chronic idiopathic urticaria and in 4/6 autoantibody-positive sera of patients who went into remission after the treatment of underlying causes.

CONCLUSIONS

These data confirm that anti-FcepsilonRIalpha autoantibodies in urticaria are mostly found in chronic urticaria. Furthermore, their detection independently of the apparent cause of the urticaria suggests that as yet unidentified mechanisms must be operative, possibly related to the chronic inflammatory process and/or individual predispositions that favor their induction.

Upregulation of TNF-alpha and IL-3 expression in lesional and uninvolved skin in different types of urticaria

BACKGROUND

Although mast cells are known to secrete a broad spectrum of proinflammatory and immunomodulatory cytokines, the role of these molecules in mast cell-dependent cutaneous inflammation is not clear.

OBJECTIVE

We decided to study biopsy specimens from lesional and nonlesional skin of patients with acute, chronic recurrent, delayed pressure, and cold urticaria; from fleeting wheals of prick test reactions to allergens; and from normal skin of nonallergic subjects.

METHODS

Cryostat sections were stained by immunohistochemistry with antibodies against IL-3, IL-8, TNF-alpha, and mast cell-specific tryptase. In serial sections with tryptase and each cytokine, reactivity of mast cells was studied as well.

RESULTS

Compared with normal skin and prick test reactions, immunoreactivity for TNF-alpha and IL-3 was significantly increased on endothelial and perivascular cells of the upper dermis in all urticaria lesions. In nonlesional skin comparable upregulation was noted on endothelial cells and for TNF-alpha on perivascular cells of patients with delayed pressure urticaria. In addition, TNF-alpha was expressed throughout the epidermis in lesional and nonlesional skin of patients with all types of urticaria, but not in normal control subjects. Sequential biopsy specimens from patients with cold urticaria showed upregulation of TNF-alpha and IL-3 on endothelial cells 30 minutes after elicitation of lesions with an ice cube. In contrast to these findings, epidermal immunoreactivity, as well as endothelial and perivascular cell expression of IL-8, were only slightly altered in urticaria compared with normal skin. In sequentially stained sections, few tryptase-positive mast cells reacted to TNF-alpha, few reacted to IL-3 in pressure urticaria only, and practically none stained for IL-8.

CONCLUSION

These findings suggest that the cytokines studied here are involved in the pathology of urticaria, possibly by inducing subthreshold inflammation in endothelial cells of uninvolved skin.