Is It Possible to Use Inflammatory Markers as Potential Biomarkers for Chronic Urticaria?

Background: This study aimed to determine whether the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) at admission affect the transition of pediatric patients diagnosed with acute spontaneous urticaria to chronic urticaria. Methods: This study included 390 patients who presented to the Department of Pediatrics at Akdeniz University Hospital with acute spontaneous urticaria between January 2020 and December 2022. A statistical comparison was made between the hematological parameters of patients who developed chronic urticaria and those who did not. Neutrophil, lymphocyte, and platelet counts, as well as NLR, PLR, and SII ratios, were used for the comparison. Results: It was observed that acute urticaria progressed to chronic urticaria in 5.8% (n = 23) of the patients. No significant differences in lymphocyte, hemoglobin, and platelet counts were observed between the group progressing to chronic urticaria and the control group (P > 0.05). However, the chronic urticaria group had higher leukocyte and absolute neutrophil counts (P = 0.009 and P < 0.001, respectively). In addition, the NLR was significantly higher in the chronic urticaria group (P = 0.029), whereas no statistically significant difference was observed in the PLR (P = 0.180). The chronic urticaria group had a significantly higher SII than the control group (P = 0.011). Conclusion: Hematological parameters, particularly NLR and SII, may be useful indicators of the transition from acute to chronic urticaria in pediatric patients. The early identification of these markers could help monitor patients and guide treatment decisions. Further comprehensive studies are required to validate these findings.

Analysis of coagulation factors in angioedema/urticaria: increased values of D-dimer and fibrinogen in isolated angioedema.

INTRODUCTION: Recent research has shown that blood coagulation and the extrinsic coagulation cascade are involved in the pathogenesis of chronic spontaneous urticaria (CSU), but little is known about the coagulation factors in angioedema. METHODS: This study included 58 participants: 29 patients with chronic angioedema (14 with isolated angioedema and 15 with angioedema with wheals) and 29 healthy controls (HCs). We compared the values of coagulation factors in patients with isolated angioedema to those with wheals. Plasma levels of D-dimer, fibrinogen, and factor VII were measured by enzyme-linked immunosorbent assay (ELISA) for all participants. RESULTS: Significantly higher D-dimer (p = 0.016; ε² = 0.381) and fibrinogen (p = 0.044; ε² = 0.331) levels were recorded in patients with angioedema (both groups) than in the HCs, with higher levels for angioedema with wheals. Factor VII and fibrinogen levels did not differ significantly between the groups with angioedema, but coagulation factors were more often elevated in both angioedema groups than in HCs. CONCLUSIONS: One characteristic of angioedema is an elevated blood coagulation potential, which may help produce fibrin and may be important in controlling angioedema attacks.

Detection and Analysis of Commonly Used Infection Indicators in Patients with Acute Urticaria.

INTRODUCTION: In this study, we investigated the correlation and clinical significance of peripheral blood leukocytes, neutrophils, C-reactive protein (CRP), and procalcitonin (PCT) in patients with acute urticaria. METHODS: Complete blood count with differential, CRP, and PCT tests were conducted on patients with acute urticaria. A total of 614 patients with acute urticaria were divided into three groups: the first group consisted of patients with elevated leukocyte and neutrophil count, the second group consisted of patients with normal leukocyte and neutrophil count, and the third group consisted of patients with abnormal leukocyte and neutrophil count. A correlation analysis was conducted to investigate the levels of leukocytes, neutrophils, CRP, and PCT in the three groups. RESULTS: The results of Kruskal-Wallis' nonparametric test revealed statistically significant variations in leukocytes, neutrophils, CRP, and PCT among the three groups (p < 0.001). However, CRP and PCT showed no statistically significant differences between the second and third groups (p < 0.001, p = 0.0041, p = 0.0032). Additional multiple comparisons in Spearman correlation analysis indicated statistically significant differences (p = 0.55). Across all groups, there was a statistically significant difference in the correlation between CRP-PCT and leukocytes-neutrophils (p = 0.53). CONCLUSION: Leukocytes and neutrophils are sensitive to the impact of medications and stress on the body. Combining CRP and PCT, as well as routine blood test, may be a comprehensive assessment of infection presence and severity in patients, providing guidance for antibiotic treatment.

The Alarmin Triad-IL-25, IL-33, and TSLP-Serum Levels and Their Clinical Implications in Chronic Spontaneous Urticaria.

This study delves into the critical role of alarmins in chronic spontaneous urticaria (CSU), focusing on their impact on disease severity and the quality of life (QoL) of patients. We investigated the alterations in alarmin levels in CSU patients and their correlations with the Urticaria Activity Score (UAS7) and the Dermatology Life Quality Index (DLQI). We analyzed serum levels of interleukin-25 (IL-25), interleukin-33 (IL-33), and thymic stromal lymphopoietin (TSLP) in 50 CSU patients, comparing these to 38 healthy controls. The study examined the relationship between alarmin levels and clinical outcomes, including disease severity and QoL. Elevated levels of IL-33 and TSLP in CSU patients (p < 0.0001) highlight their potential role in CSU pathogenesis. Although IL-25 showed higher levels in CSU patients, this did not reach statistical significance (p = 0.0823). Crucially, IL-33's correlation with both UAS7 and DLQI scores underscores its potential as a biomarker for CSU diagnosis and severity assessment. Of the alarmins analyzed, IL-33 emerges as particularly significant for further exploration as a diagnostic and prognostic biomarker in CSU. Its substantial correlation with disease severity and impact on QoL makes it a compelling candidate for future research, potentially serving as a target for therapeutic interventions. Given these findings, IL-33 deserves additional investigation to confirm its role and effectiveness as a biomarker and therapeutic target in CSU.

Plasma levels of D-dimer and fibrin degradation products correlate with bullous pemphigoid severity: a cross-sectional study.

Bullous pemphigoid (BP), the most frequent blistering dermatosis in the elderly, is associated with increased mortality. The severity of BP can be assessed by detecting the anti-BP180 immunoglobulin G (IgG) concentration, but the lab test is not available in many community clinics. BP patients are usually in a hypercoagulable state with increased levels of D-dimer and fibrin degradation products (FDPs). We aimed to evaluate the use of D-dimer and FDPs in assessing BP severity. We compared the levels of plasma D-dimer, plasma FDPs, eosinophil counts, eosinophil cationic protein, and serum anti-BP180 IgG concentration between 48 typical BP patients and 33 Herpes zoster (HZ) patients (control group). Correlational analyses were conducted to determine the relationships between the lab values and common BP severity markers. The plasma D-dimer and FDP levels were higher in BP patients than in HZ controls (D-dimer: 3297 ± 2517 µg/L vs. 569.70 ± 412.40 µg/L; FDP: 9.74 ± 5.88 mg/L vs. 2.02 ± 1.69 mg/L, respectively, P < 0.0001). Significant positive correlations were found between D-dimer/FDP levels and BP severity markers (i.e. anti-BP180 IgG concentration [D-dimer: r = 0.3928, P = 0.0058; FDP: r = 0.4379, P = 0.0019] and eosinophil counts [D-dimer: r = 0.3625, P = 0.0013; FDP: r = 0.2880, P = 0.0472]) in BP patients. We also found an association between FDP and urticaria/erythema lesions (r = 0.3016, P = 0.0372), but no other BPDAI components. In 19 BP patients with complete remission after systemic glucocorticoid treatment, D-dimer and FDP levels decreased post-therapy (D-dimer: 5559 ± 7492 µg/L vs. 1738 ± 1478 µg/L; P < 0.0001; FDP: 11.20 ± 5.88 mg/L vs. 5.13 ± 3.44 mg/L; P = 0.0003), whereas they did not in BP patients with treatment resistant. Plasma D-dimer and FDP are convenient markers to evaluate BP severity assistant on BPDAI and eosinophil counts. FDP is also helpful for inflammatory lesions in BP patients.

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.

The Role of Interleukin 10 and 18 in Chronic Spontaneous Urticaria Pathogenesis in the Context of Angioedema Coexistence.

Chronic spontaneous urticaria (CSU) is defined using clinical symptoms as spontaneous occurrence of itchy wheals and/or angioedema for at least 6 weeks. Angioedema is underdiagnosed in CSU patients, and its presence has significant negative impact on health-related quality of life, daily activities, health care resource utilization, and work. Various cytokines have been found to be involved in pathogenesis of CSU. To study levels of interleukin (IL)-10 and IL-18 in CSU patients and to look for the differences in CSU subgroups divided with regard to angioedema reoccurrence, we included consecutive CSU patients into the study. To assess disease activity, urticaria activity score was used. In addition, we calculated disease duration time. In all groups, Il-10 and Il-18 serum concentrations were measured. The study involved 52 patients with CSU and 47 healthy volunteers. The IL-10 level was statistically significantly higher in patients with CSU compared to the control group. There were no significant differences in level of IL-18 between those groups. Comparison of patients with CSU and angioedema with those without angioedema showed no significant differences in level of IL-10 and IL-18. We see the need for further studies of serum levels of IL-10 and IL-18 to better understand the pathogenesis of the disease and to find markers useful in predicting the symptom type in the course of CSU.

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.

D-dimer concentrations in acute urticaria in children.

INTRODUCTION: Urticaria is a clinical entity presenting as wheals, angioedema, or both simultaneously. Elevated D-dimer levels were reported in the course of chronic spontaneous urticaria. Data regarding D-dimer levels in acute urticaria in children are limited. OBJECTIVES: To assess potential associations between duration of glucocorticosteroid (GCS) therapy and D-dimer concentrations in children with acute urticaria. PATIENTS, MATERIALS, AND METHODS: Hospital records of 106 children (59 females), aged 5.57 ± 4.91 years, hospitalized in 2014-2018 were analyzed retrospectively. The study group consisted of pediatric patients admitted to the hospital due to severe acute urticaria resistant to antihistaminic treatment that was ordered in the ambulatory care (out-patient clinic). Patients were divided into subgroups: no GCS treatment, short-duration treatment (up to 5 days) and long-duration treatment (6 and more days) GCS treatment. Simultaneously, patients received antihistaminic drugs. D-dimer level and other inflammatory factors such as white blood cell (WBC) count, platelet (PLT) count, and C-reactive protein (CRP) in each group were analyzed. RESULTS: The D-dimer level was elevated in 51% of cases. In the subgroup with longer GCS treatment, D-dimer concentration was significantly higher in comparison to patients with a shorter GCS course. There were no differences in the distribution of CRP, PLT, and WBC concentrations between these subgroups. CONCLUSIONS: In the studied group of children, there was a tendency for higher D-dimer levels in patients, who required a longer GCS treatment. This finding is hypothesis-generating and requires further investigation to confirm if D-dimers can be used as a prognostic factor in acute urticaria in children.

Hereditary alpha-tryptasemia in 101 patients with mast cell activation-related symptomatology including anaphylaxis.

BACKGROUND: Hereditary alpha-tryptasemia (HαT) is an autosomal dominant genetic trait characterized by multiple copies of the alpha-tryptase gene at the TPSAB1 locus. Previously described symptomatology involves multiple organ systems and anaphylaxis. The spectrum of mast cell activation symptoms is unknown, as is its association with specific genotypes. OBJECTIVE: To describe clinical, laboratory, and genetic characteristics of patients referred for the evaluation of mast cell activation-related symptoms and genotype-confirmed HαT. METHODS: We retrospectively describe clinical characteristics, baseline tryptase, and tryptase genotype in 101 patients. Patients were referred for mast cell activation-related symptoms and underwent genotyping to confirm diagnosis of HαT. RESULTS: Of 101 patients, 80% were female with average tryptase of 17.2 ng/mL. Tryptase was less than 11.4 ng/mL in 8.9% and greater than 20 ng/mL in 22.3% (range 6.2-51.3 ng/mL). KIT D816V mutation was negative in all subjects tested. 2α:3ß was the most common genotype but did not correlate with tryptase levels. Unprovoked anaphylaxis was noted in 57% of the subjects with heterogeneous genotypes. Most common symptoms include gastrointestinal, cutaneous, psychiatric, pulmonary, cardiovascular, and neurologic. A total of 85% of patients were taking H1- or H2-antihistamines with partial symptom relief. Omalizumab was effective at suppressing anaphylaxis or urticaria in 94% of the patients. CONCLUSION: HαT encompasses a broad range of baseline tryptase and should be considered in patients with symptoms of mast cell activation and tryptase levels greater than 6.2 ng/mL. Patients may present with complex symptomatology including cutaneous, gastrointestinal, neurologic, and psychiatric symptoms and anaphylaxis, some of which respond to omalizumab.

miR-126-3p and miR-16-5p as novel serum biomarkers for disease activity and treatment response in symptomatic dermographism.

Symptomatic dermographism (SD) is the most common form of physical urticaria. So far no promising serum biomarkers for SD have been reported. Recently, microRNAs (miRNAs) have been reported to be serum biomarkers for chronic spontaneous urticaria. However, association of miRNAs with SD remains unclear. We enrolled 55 SD patients and 52 healthy controls in this study. We found that serum expressions of miR-126-3p and miR-16-5p were significantly downregulated in active SD patients and upregulated in remission. The area under the curve values of miR-126-3p (0.769) and miR-16-5p (0.789) showed significant ability to diagnostic SD. Serum level of vascular endothelial growth factor (VEGF)-A, a known target of the two miRNAs, was significantly increased in active SD patients and decreased in remission. Moreover, serum VEGF-A level was inversely correlated with expressions of miR-126-3p and miR-16-5p. Our findings indicate that miR-126-3p and miR-16-5p can serve as potential serum biomarkers for SD.

Correlations between disease activity, autoimmunity and biological parameters in patients with chronic spontaneous urticaria.

Summary: Background. Biomarkers of disease activity/severity and criteria of autoimmune chronic spontaneous urticaria (CSU) are still a matter of debate. Objective. To investigate possible correlations between clinical and biological markers and their associations with: 1) disease activity, 2) resistance to H1-antihistamines, 3) autoimmunity and 4) autologous serum skin test (ASST) in patients with CSU. To also analyze biological parameter modifications in patients with CSU treated with omalizumab. Materials and methods. Disease activity, H1-antihistamines response and presence of concomitant autoimmune disease were prospectively recorded in 95 patients with CSU. For 60 of them, ASST was performed. Broad biological analysis were performed. Results. C-reactive protein (CRP) serum levels were higher in H1-antihistamines unresponders (p less-than 0.0001) and in more active diseases (p = 0.033). D-dimer plasma levels were higher in H1-antihistamines unresponders (p = 0.008) and in patients with autoimmune status (concomitant autoimmune disease and/or with autoantibodies) (p = 0.016). Total immunoglobuline E (IgE) serum level was lower in patients with positive ASST. Blood basophil counts were lower in patients with CSU and especially in H1-antihistamines unresponders (p = 0.023), in patients with more active disease (p = 0.023), with positive ASST (p = 0.001), and with autoimmune status (p = 0.057). Conversely, under omalizumab, a decrease of CRP (p = 0.0038) and D-dimer serum/plasma levels (p = 0.0002) and an increase of blood basophil counts (p = 0.0023) and total IgE serum levels (p = 0.0007) were observed. Conclusions. This study brings additional evidences of interest to investigate IgE, D-dimer serum/plasma levels and basophil blood counts in patients with CSU as they could be correlated to disease activity, response to treatment and/or autoimmunity.

Is vitamin D concentration an indicator of the severity of atopic dermatitis and chronic spontaneous urticaria in adults?

Atopic dermatitis (AD) and chronic spontaneous urticaria (CSU) are common chronic and recurrent dermatoses. The role of vitamin D in the immunological processes, including the development of inflammation, has been the subject of numerous studies. The feasible measurement of vitamin D serum concentration and possibly supplementation necessitates the assessment of its impact on the clinical severity of mentioned diseases. AIM: The aim of the study was to determine the relationship between blood serum vitamin D concentration and the severity of clinical symptoms in the group of adults suffering from AD or CSU. MATERIALS AND METHODS: The study was conducted in 2018 on groups of patients suffering from AD or CSU. Serum vitamin D concentration was determined by electrochemiluminescence assay. Student's t-test was adopted to compare vitamin D levels between groups. Spearman's rank correlation coefficient was used to assess the correlation between vitamin D concentration and the severity of AD (according to the SCORAD scale) and CSU (according to the UAS 7 scale). RESULTS: There was not found any statistically significant relationship between the severity of skin lesions scores in the course of AD and CSU and serum vitamin D concentration.

Characteristics of patients with bullous pemphigoid: comparison of classic bullous pemphigoid to non-bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is the most common subepidermal autoimmune blistering disease. Patients occasionally present with a clinical picture of pruritus/urticaria alone for months and do not even develop blisters over time. Only few studies have investigated this subgroup of non-bullous pemphigoid (NBP). OBJECTIVE: To evaluate the demographic and clinical characteristics of BP patients with or without blisters at the time of diagnosis. METHODS: A retrospective study based on the medical records of 115 BP patients. Collected data included demographic characteristics, clinical presentation, treatment and response to treatment. RESULTS: Thirty-six patients presented with pruritus/urticaria (31.3%), and 79 presented with blisters (68.7%), with mean ages of 77.5 and 76.0, respectively, at diagnosis and an equal female:male ratio. The level of immunoglobulin E (IgE) was 4.1 times higher, and the mean blood eosinophil count was significantly increased in the pruritus/urticaria group. Remission rate at 3 months and relapse rate were similar between the groups. Median follow-up period was 9 months (range 3-18). Only 23% of the patients with pruritus/urticaria developed blisters. CONCLUSIONS: A significant number of BP patients present without blisters. We found no significant epidemiological or clinical differences from the classic BP patients aside from significantly elevated IgE and blood eosinophil levels. Similar results in larger cohort studies might be the foundation for a change in clinical protocols regarding the diagnosis and recommended treatment for the elderly presenting with pruritus/urticaria only.

[Hypocomplementemic urticarial vasculitis syndrome: a rare but not always benign condition]. / HUVS ­ sällsynt men inte ofarlig vaskulit associerad med urtikaria - Svensk studie visar en årlig incidens på 0,7 fall per miljon invånare.

Although more than 45 years have passed since hypocomplementemic urticarial vasculitis (HUVS) was first described by McDuffie and colleagues at the Mayo clinic, data on epidemiology, disease outcomes, prognosis and clinical features are scarce. Recently, we published the first epidemiological study of HUVS including data on incidence, prevalence, disease outcomes, prognosis and clinical features using data from two separate Swedish regions during a period of 16 years. The estimation of incidence and prevalence rates indicates that HUVS is rare but not always benign. Renal and lung manifestations were severe in some cases, highlighting the need for careful screening and monitoring of this potentially serious condition. It is reasonable to suspect HUVS in patients with unexplained systemic inflammation combined with >6 months of urticaria. Special attention should be paid to patients with recent-onset dyspnea and proteinuria.

Serum amyloid A levels in acute and chronic urticaria.

BACKGROUND: Serum amyloid A is an acute-phase protein. There is no available data regarding serum amyloid A levels in patients with acute (AU) and chronic urticaria (CU). OBJECTIVE: To investigate the association between serum amyloid A and urticaria. METHODS: This was a case-control study of 81 patients who visited our Hospital between June and December 2016 with a diagnosis of urticaria. Eighty healthy controls (HC) who visited for routine health examination and physical checkups were recruited. Serum amyloid A and C-reactive protein levels were measured by automated methods. RESULTS: Serum amyloid A and C-reactive protein levels were significantly higher in AU (Serum amyloid A: 207.1 (6.7-439.0) mg/L; C-reactive protein: 16.0 (0.2-90.0) mg/L) and CU (Serum amyloid A: 6.5 (2.5-35.8) mg/L; C-reactive protein: 1.0 (0.1-16.0) mg/L) compared with HC (Serum amyloid A: 5.04 (2.0-9.1) mg/L; C-reactive protein: 1.2 (0.1-5.6) mg/L), and in AU compared with CU (all P<0.05). There were no differences between the CU and HC group. In CU, Serum amyloid A levels in those with moderate/severe urticaria (median, 16.4 (9.7-35.8) mg/L) were higher than in those with mild urticaria (median, 5.7 (2.5-9.5) mg/L) and HC (all P<0.05). Serum amyloid A and C-reactive protein levels exceeded the normal lab range in 90.7% and 72.1% patients with AU compared with 28.9% and 13.2% patients with CU, respectively. Significant positive correlations were found between serum amyloid A and C-reactive protein (r = 0.562, P < 0.001). STUDY LIMITATIONS: There was no comparison between active disease and remission. CONCLUSION: There was an association between serum amyloid A levels and urticaria. Higher serum amyloid A levels were associated with AU and more severe CU. Serum amyloid A may help to identify CU patients earlier.

Serum amyloid A levels in acute and chronic urticaria

Abstract: Background: Serum amyloid A is an acute-phase protein. There is no available data regarding serum amyloid A levels in patients with acute and chronic urticaria (CU). Objective: To investigate the association between serum amyloid A and urticaria. Methods: This was a case-control study of 81 patients who visited our Hospital between June and December 2016 with a diagnosis of urticaria. Eighty healthy controls (HC) who visited for routine health examination and physical checkups were recruited. Serum amyloid A and C-reactive protein levels were measured by automated methods. Results: Serum amyloid A and C-reactive protein levels were significantly higher in AU (Serum amyloid A: 207.1 (6.7-439.0) mg/L; C-reactive protein: 16.0 (0.2-90.0) mg/L) and CU (Serum amyloid A: 6.5 (2.5-35.8) mg/L; C-reactive protein: 1.0 (0.1-16.0) mg/L) compared with HC (Serum amyloid A: 5.04 (2.0-9.1) mg/L; C-reactive protein: 1.2 (0.1-5.6) mg/L), and in AU compared with CU (all P<0.05). There were no differences between the CU and HC group. In CU, Serum amyloid A levels in those with moderate/severe urticaria (median, 16.4 (9.7-35.8) mg/L) were higher than in those with mild urticaria (median, 5.7 (2.5-9.5) mg/L) and HC (all P<0.05). Serum amyloid A and C-reactive protein levels exceeded the normal lab range in 90.7% and 72.1% patients with AU compared with 28.9% and 13.2% patients with CU, respectively. Significant positive correlations were found between serum amyloid A and C-reactive protein (r = 0.562, P < 0.001). Study limitations: There was no comparison between active disease and remission. Conclusion: There was an association between serum amyloid A levels and urticaria. Higher serum amyloid A levels were associated with AU and more severe CU. Serum amyloid A may help to identify CU patients earlier.