Use of biologics in chronic spontaneous urticaria - beyond omalizumab therapy?

In chronic spontaneous urticaria (CSU), itchy wheals, angioedema, or both occur regularly, often daily, and for years. An effective therapy for CSU aims at achieving complete symptom control. The current guideline for the management of CSU patients recommends non-sedative anthistamines in standard or up to 4-fold higher dosages as 1 and 2 line treatment. For most CSU patients this treatment is not sufficient; for them, the anti-IgE antibody omalizumab is the therapy of choice. Although good to very good symptom control can be achieved in most cases, there are many patients with insufficient response. For these patients, but also as an alternative to therapy with omalizumab, numerous other biologicals are currently under development. In this review, we provide an overview of possible future biologic therapies for chronic urticaria.

Serum prolactin level in chronic urticaria: Is bromocriptine inducing remission in chronic urticaria?

BACKGROUND

Chronic urticaria (CU) is a disturbing disease with a negative impact on quality of life. Despite of several clinical studies on CU patients, its pathogenesis is poorly understood. Prolactin (PRL) is peptide hormone has immunomodulatory effects in some immune inflammatory skin diseases.

AIM

To elucidate any possible relationship between the immunomodulatory effects of PRL and CU. Besides, the study aims to investigate the crucial role of antiprolactin drugs in the management of CU patients.

PATIENTS AND METHODS

The serum PRL level of 40 female patients with CU was measured using the electrochemiluminescence immunoassay. The activity of CU was assessed by European Academy of Allergology and Clinical Immunology; Global Allergy and Asthma European Network; European Dermatology Forum (EAACI/GA2LEN/EDF) activity score. Patients with high PRL level had been given anti prolactin therapy to normalize their PRL levels. Then, the disease activity was reassessed in these patients.

RESULTS

The serum PRL level was high in 8 of 40 (20%) patients (43.18 ± 12.81). Half of patients with high PRL level had remission after treatment of hyperprolactinemia (p = .001).

CONCLUSIONS

Serum PRL levels could not be considered as a marker of the disease activity in CU patients.

Pattern of chronic urticaria and value of autologous serum skin test in Sohag Province, Upper Egypt

Background

Chronic urticaria (CU) is a debilitating disorder with variable clinical course. It is characterized by hives occurring for at least 6 weeks, and is classified as spontaneous or inducible.

Objective

The aim of this study was to detect the pattern of CU, to study association between results of autologous serum skin test (ASST) and urticaria severity score (USS), and to detect serum levels of anti IgE receptors antibodies.

Methods

This study included all patients attending the Dermatology Outpatient Clinic, Sohag University Hospital, who were diagnosed as CU from April 2015 to March 2016. ASST and serum level of anti IgE receptor antibodies was assessed using ELISA. Data were analyzed by SPSS version 16, using descriptive statistics, Kruskal-Wallis and Mann-Whitney U test.

Results

A total of 108 patients with CU were included in the study. Females with mean age 33±12.4 years were more affected. A total of 58.3% complained of CSU, 6.5% physical urticaria and 35.2% mixed type of CU. According to USS, mild score represented 20.4%, moderate 46.3% and severe in 33.3%. ASST showed positive in 38% of patients. There was a statistically significant relation between ASST and USS and duration of CU. This indicates that more severe symptoms and prolonged duration of CU are observed in positive ASST (autoreactive type). In all, 91% of the anti IgE receptor antibodies positive patients had positive ASST.

Conclusion

In conclusion, chronic urticaria is not an uncommon disease in our locality which represented 1.13% of our patients. Urticaria severity score and duration of urticaria was higher in positive ASST patients and hence the autoreactive type.

Amelioration of patients with chronic spontaneous urticaria in treatment with vitamin D supplement

BACKGROUND

Spontaneous urticaria is a common allergic skin condition affecting 0.5-1% of individuals and may burden on health care expenditure or may be associated with remarkable morbidity.

AIM

In this study, we measured the effect of vitamin D supplementation in patients with a diagnosis of CSU. Furthermore, quality of life and cytokine changes were evaluated.

METHODS

The clinical trial was conducted on 20 patients with idiopathic chronic urticaria. Vitamin D was administered orally for 8 weeks and disease activity was measured pre- and post-treatment using USS and DLQI. On the other hand expressions of IL-17, IL-10, Foxp3, and TGF-β by Real-time RT-PCR were assessed.

RESULTS

USS questionnaire showed that severity of idiopathic urticaria after the intervention, which compared with the first day reached a significant 55% reduction. The DLQI quality of life questionnaire 2 months after treatment showed 55% improvement. Along with the significant improvement of clinical symptoms, use of vitamin D increase FOXP3 gene expression and downregulation of IL-10, TGF-B, and FOXP3, IL-17, but these changes were not statistically significant.

LIMITATION

These might happen due to lack of enrolled population in the investigation.

CONCLUSION

Vitamin D can be used along with standard medical care and it's a safe and cost-effective method for the treatment of chronic urticaria with deficiency of vitamin D.

The burden of chronic spontaneous urticaria is substantial: Real-world evidence from ASSURE-CSU

BACKGROUND

Chronic spontaneous urticaria (CSU) can be debilitating, difficult to treat, and frustrating for patients and physicians. Real-world evidence for the burden of CSU is limited. The objective of this study was to document disease duration, treatment history, and disease activity, as well as impact on health-related quality of life (HRQoL) and work among patients with inadequately controlled CSU, and to describe its humanistic, societal, and economic burden.

METHODS

This international observational study assessed a cohort of 673 adult patients with CSU whose symptoms persisted for ≥12 months despite treatment. Demographics, disease characteristics, and healthcare resource use in the previous 12 months were collected from medical records. Patient-reported data on urticaria and angioedema symptoms, HRQoL, and work productivity and activity impairment were collected from a survey and a diary.

RESULTS

Almost 50% of patients had moderate-to-severe disease activity as reported by Urticaria Activity Score. Mean (SD) Dermatology Life Quality Index and Chronic Urticaria Quality of Life Questionnaire scores were 9.1 (6.62) and 33.6 (20.99), respectively. Chronic spontaneous urticaria markedly interfered with sleep and daily activities. Angioedema in the previous 12 months was reported by 66% of enrolled patients and significantly affected HRQoL. More than 20% of patients reported ≥1 hour per week of missed work; productivity impairment was 27%. These effects increased with increasing disease activity. Significant healthcare resources and costs were incurred to treat CSU.

CONCLUSIONS

Chronic spontaneous urticaria has considerable humanistic and economic impacts. Patients with greater disease activity and with angioedema experience greater HRQoL impairments.

Why a registry of Chronic Urticaria (CUR) is needed

Chronic urticaria (CU) has a major effect on patients’ quality of life. While there have been progressive advances regarding its pathogenesis and treatment, much remains to be done.

Registries of other chronic non-communicable diseases have shown many benefits, such as additional basic knowledge and management approaches to diabetes mellitus. Standards of care as well as diagnostic approaches can be elaborated and compared from different sites, using validated instruments. Registries in allergic diseases are also becoming well recognized, and the first registry on CU, accessible from SLaai’s webpage, includes parameters for identification, evaluation and management. In our vision, informatics strategies have the potential to improve care for chronic illnesses such as CU. The registry represents a valid instrument from which to obtain a sufficient sample size for epidemiological studies and/or clinical research planning, including feasibility and potential enrollment. It can also provide invaluable data for adapting guidelines to local populations, as well as diagnostic approaches and cost-effective interventions in the context of organizational efforts to improve patient care.

CRP relevance in clinical assessment of chronic spontaneous urticaria Tunisian patients

BACKGROUND

Chronic spontaneous urticaria (CSU) is a common dermatological condition defined by the sudden occurrence of daily wheals and pruritus for at least six weeks. Multifactorial origin is suggested such as oxidative stress. This latter may play a double role as a trigger and remnant agent.

OBJECTIVES

The first aim of this study is to investigate antioxidant status, inflammatory proteins, hematologic counts and clinical assessment in CSU patients. The second aim is to evaluate the effect of a first-line treatment: desloratadine 5 mg/d on these different parameters.

PATIENTS AND METHODS

This study enrolled 30 CSU patients and same number of controls. We assessed the urticaria activity score (UAS), total antioxidant status (TAS), glutathione S-transferase (GST), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), albumin, alpha1, alpha2, beta1 beta2, gamma globulins, c-reactive protein (CRP) and hematologic numeration.

RESULTS

At baseline alpha1, alpha2, beta1, beta2, gamma globulins, CRP, SOD activity, leukocytes and basophils were significantly higher in patients versus controls (p < 0.05). TAS, GST, CAT, GPx and albumin were significantly low in patients versus controls (p < 0.05). After treatment, TAS, GST and GPx were significantly increased in patients versus patients before treatment (p < 0.001). SOD, alpha1, alpha2, beta1, beta2, gamma globulins, CRP, albumin, leukocytes and basophils were significantly decreased after treatment versus before treatment (p < 0.05). A significant correlation between CRP and UAS (r = 0.3; p = 0.011) was noted. UAS assessment revealed the efficacy of 30 d-antihistaminic treatment.

CONCLUSIONS

Desloratadine exerted anti-inflammatory and antioxidant effects on CSU patients revealed by CRP. Patients' remission was synergistic to CRP attenuation emphasizing CRP relevance for CSU clinical assessment.

Advances in Understanding and Managing Chronic Urticaria

There have been recent advances in the classification and management of chronic urticaria. The new term chronic spontaneous urticaria (CSU) has replaced chronic idiopathic urticaria and chronic autoimmune urticaria. In addition, chronic inducible urticaria (CINDU) has replaced physical urticaria and includes other forms of inducible urticaria, such as cholinergic and aquagenic urticaria. Furthermore, novel research has resulted in a new understanding with guidelines being revised in the past year by both the American Academy of Allergy, Asthma, and Immunology (AAAAI) and the European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Network (GA ²LEN)/European Dermatology Forum (EDF)/World Allergy Organization (WAO). There are some differences in the recommendations, which will be discussed, but the core updates are common to both groups. The basic treatment for chronic urticaria involves second-generation non-sedating non-impairing H ₁ antihistamines as first-line treatment. This is followed by up to a 4-fold increase in the licensed dose of these H ₁ antihistamines. The major therapeutic advance in recent years has been in third-line treatment with omalizumab, a humanized monoclonal anti-immunoglobulin E (anti-IgE) antibody that prevents binding of IgE to the high-affinity IgE receptor. Several multicenter randomized controlled trials have shown safety and efficacy of omalizumab for CSU. There are also some small studies showing efficacy of omalizumab in CINDU. While there were previously many treatment options which were lacking in strong evidence, we are moving into an era where the treatment algorithm for chronic urticaria is simplified and contains more evidence-based, effective, and less toxic treatment options.

Effects of Helicobacter pylori Eradication in Chronic Spontaneous Urticaria: Results from a Retrospective Cohort Study

BACKGROUND AND OBJECTIVE

Helicobacter pylori (Hp) infection has been hypothesised to play a major role in the pathogenesis of chronic spontaneous urticaria (CSU). Despite only weak evidence from Hp eradication studies, screening for Hp infection is still recommended in several CSU guidelines. The aim of this study was to investigate the effect of Hp eradication in combination with standard CSU treatment in Hp-positive compared with Hp-negative patients, applying the latest guidelines for both diseases.

METHODS

138 consecutive patients with CSU were enrolled in this retrospective cohort study. All patients underwent gastroscopy and Hp status was determined by urease testing and histologic examination. Seventy-five patients were diagnosed as Hp negative and 47 patients fulfilled criteria for definite Hp infection, 45 of whom received eradication therapy. Sixteen patients who received eradication therapy without an appropriate indication served as the medication control. All patients received symptomatic treatment with antihistamines and/or glucocorticoids regardless of Hp status. Partial response (PR) was defined as subjective amelioration of CSU symptoms; patients returning for further CSU treatment within 6 months were considered non-responders/relapsers (NRs).

RESULTS

The prevalence of Hp infection was comparable with Hp seroprevalence data reported for healthy western populations. Standard treatment of CSU led to relief of symptoms independent of Hp status. Hp eradication by standard triple therapy had no additional effect on PR (p = 0.32) or NR (p = 0.50).

CONCLUSIONS

Hp eradication has no discernible effect on CSU beyond that of standard CSU therapy. Therefore, Hp eradication should only be initiated in accordance with currently accepted indications of Hp treatment guidelines.

Indirect Immunofluorescence for the Detection of Autoimmune Urticaria

BACKGROUND

An autoimmune basis is believed to be responsible for about half of chronic spontaneous urticaria (CSU) cases. The autologous serum skin test is used as a possible indicator, but there is currently no test that directly indicates an autoimmune etiology. In this study, an indirect immunofluorescence was used to identify patients with autoantibodies directed at mast cells.

METHODS

Two substrates were used including paraffin embedded sections of skin biopsies from an infant with bullous mastocytosis and cord blood-derived mast cells (CBMC). Sera from 76 patients with CSU were incubated with substrates and conjugated with human IgG.

RESULTS

Using the bullous mastocytosis preparations, positive indirect immunofluorescence was found in 46% (n = 76), while the CBMC substrate was positive in 39% (n = 70).

CONCLUSION

The IgG autoantibodies directed at mast cells could be detected in about half the patients with CSU. Indirect immunofluorescence should be considered as an indicator of the autoimmune form of CSU.

Unmet medical needs for chronic spontaneous urticaria patients: highlighting the real-life clinical practice in Taiwan

BACKGROUND

Treatment guidelines for chronic spontaneous/idiopathic urticaria (CSU) are available; however, only 50% of patients are well controlled with approved doses of H1-antihistamines, and certain patients remain symptomatic despite receiving up to 4× the approved dose of H1-antihistamines plus H2 antihistamines and/or leucotriene-receptor antagonists.

OBJECTIVES

To highlight real-life clinical practice in Taiwan and to understand the unmet medical needs of CSU patients.

METHODS

A nationwide cross-sectional, observational survey of 50 dermatologists and 200 CSU patients was conducted between June 2013 and November 2013. Face-to-face interviews of dermatologists and online interviews of CSU patients were conducted independently.

RESULTS

Dermatologists reported that dermographism and blood tests were the most commonly used diagnostic methods to confirm the diagnosis. The key driving factor for most clinic-based dermatologists (70%) in choosing a treatment was 'response to my medicines', and most preferred H1-antihistamines and steroids for treating CSU patients, whereas most hospital-based dermatologists (85%) gave higher priority to 'severity and impact of the conditions'. Patients were reported to have high psychological pressures and significant impact of CSU on their daily activity. In addition, CSU patients were not satisfied with their current treatment and 69% of patients switched their first-consulted physician. Furthermore, lack of information and concerns about side-effects were major factors which held back patients from seeking Western treatment.

CONCLUSIONS

There is an unmet medical need of CSU patients in Taiwan highlighting gaps among guidelines, real-life clinical practice, patients' perceptions and patients' knowledge of their disease.

Hashimoto's disease is a frequent comorbidity and an exacerbating factor of chronic spontaneous urticaria

BACKGROUND

The precise pathogenesis of chronic spontaneous urticaria (CSU) remains unknown. However, an important association between CSU and autoimmune disorders such as Hashimoto's disease (HD) has been reported. We investigated the frequency of HD as a comorbidity of CSU and the prevalence rate of autoreactivity among CSU patients with HD.

PATIENTS AND METHODS

The presence of thyroid autoantibodies and the levels of thyroid hormones were examined in 40 CSU patients who showed urticaria symptoms for >4 weeks. Patients who were diagnosed with HD, including subclinical ones, and were in need of treatment received thyroid therapy, and the changes in their urticarial symptoms were observed. An autologous serum skin test (ASST) was also performed to examine the relation of CSU with autoreactivity.

RESULTS

Eleven of the 40 CSU patients were diagnosed with HD, and 4 of the 5 patients who received and completed thyroid therapy showed considerable remission of urticarial symptoms during and after treatment. In addition, the rate of positive ASST results tended to be higher in CSU patients with HD (5 of 7) than in those without HD (2 of 6).

CONCLUSIONS

The comorbidity rate of HD in CSU patients was high, and such patients tended to have a positive ASST. Thyroid therapy in CSU patients with HD can lead to a considerable remission of urticarial symptoms, which may suggest that HD is possibly involved in the aetiology of CSU, or is at least a potential exacerbating factor for CSU.

Validation of an ICD-9-based claims algorithm for identifying patients with chronic idiopathic/spontaneous urticaria

BACKGROUND

There is no specific International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code for chronic idiopathic urticaria or spontaneous urticaria (CIU/CSU), a skin condition characterized by hives and angioedema lasting at least 6 weeks with no known cause.

OBJECTIVE

To validate an ICD-9-CM-based algorithm for identification of patients with CIU/CSU and thus facilitate claims-based research.

METHODS

Patient records were reviewed at 4 US practices. Patients included in the study were from a random sample of those identified by their physician as having CIU/CSU or because they met the following diagnosis-based algorithm: (1) at least 2 outpatient ICD-9-CM diagnosis codes 708.1, 708.8, or 708.9 at least 6 weeks apart or (2) 1 outpatient diagnosis of 708.1, 708.8, or 708.9 and 1 diagnosis of 995.1 at least 6 weeks apart. Data collected included ICD-9-CM codes, diagnoses of urticaria and allergy-related conditions, and medication use. Sensitivity and positive predictive value were calculated. The study was approved by the Western Institutional Review Board.

RESULTS

One hundred forty-nine patient records were reviewed (mean age 41.1 years; 73.8% were women; 69.1% were white): 115 were identified with the diagnosis-based algorithm, 90 were patients with "known CIU/CSU", and 56 were in the 2 groups. The mean duration of CIU/CSU was 2.9 to 3.1 years. The 2 cohorts most frequently had diagnoses of idiopathic urticaria, unspecified urticaria, and other specified urticaria. The diagnosis-based algorithm had a positive predictive value of 90.4% and a sensitivity of 71.1%.

CONCLUSION

The high positive predictive value suggests that patients identified using the algorithm are highly likely to have CIU/CSU. The 71.1% sensitivity suggests that most patients with CIU/CSU will be identified. The validation statistics support the use of the diagnosis-based algorithm in claims-based research, although future studies could refine the algorithm further.

Insights and advances in chronic urticaria: a Canadian perspective

In the past few years there have been significant advances which have changed the face of chronic urticaria. In this review, we aim to update physicians about clinically relevant advances in the classification, diagnosis and management of chronic urticaria that have occurred in recent years. These include clarification of the terminology used to describe and classify urticaria. We also detail the development and validation of instruments to assess urticaria and understand the impairment on quality-of-life and the morbidity caused by this disease. Additionally, the approach to management of chronic urticaria now focuses on evidence-based use of non-impairing, non-sedating H1-antihistamines given initially in standard doses and if this is not effective, in up to 4-fold doses. For urticaria refractory to H1-antihistamines, omalizumab treatment has emerged as an effective, safe option.

H1-antihistamines for chronic spontaneous urticaria

Background Chronic spontaneous urticaria (CSU) is characterised by the development of crops of red, itchy, raised weals or hives with no identifiable external cause.Objectives To assess the effects of H1-antihistamines for CSU.Search methods We searched the following databases up to June 2014: Cochrane Skin Group Specialised Register, CENTRAL (2014, Issue 5), MEDLINE(from 1946), EMBASE (from 1974) and PsycINFO (from 1806). We searched five trials registers and checked articles for references to relevant randomised controlled trials.Selection criteria We included randomised controlled trials of H1-antihistamines for CSU. Interventions included single therapy or a combination of H1-antihistamines compared with no treatment (placebo) or another active pharmacological compound at any dose.Data collection and analysis We used standard methodological procedures as expected by The Cochrane Collaboration.Our primary outcome measures were proportion of participants with complete suppression of urticaria: 'good or excellent' response,50% or greater improvement in quality of life measures, and adverse events.We present risk ratios (RR) with 95% confidence intervals(CIs). Main results We identified 73 studies (9759 participants); 34 studies provided data for 23 comparisons. The duration of the intervention was up to two weeks (short-term) or longer than two weeks and up to three months (intermediate-term).Cetirizine 10mg once daily in the short term and in the intermediate term led to complete suppression of urticaria by more participants than was seen with placebo (RR 2.72, 95% CI 1.51 to 4.91). For this same outcome, comparison of desloratadine versus placebo in the intermediate term (5 mg) (RR 37.00, 95% CI 2.31 to 593.70) and in the short term (20 mg) (RR 15.97, 95% CI 1.04 to 245.04)favoured desloratadine, but no differences were seen between 5 mg and 10 mg for short-term treatment.Levocetirizine 20 mg per day (short-term) was more effective for complete suppression of urticaria compared with placebo (RR 20.87,95% CI 1.37 to 317.60), and at 5 mg was effective in the intermediate term (RR 52.88, 95% CI 3.31 to 843.81) but not in the shortterm, nor was 10 mg effective in the short term.Rupatadine at 10 mg and 20 mg in the intermediate term achieved a 'good or excellent response' compared with placebo (RR 1.35,95% CI 1.03 to 1.77).Loratadine (10 mg) versus placebo (RR 1.86, 95% CI 0.91 to 3.79) and loratadine (10 mg) versus cetirizine (10 mg) (RR 1.05, 95%CI 0.76 to 1.43) over short-term and intermediate-term treatment showed no significant difference for 'good or excellent response' or for complete suppression of urticaria, respectively.Loratadine (10 mg) versus desloratadine (5 mg) (intermediate-term) showed no statistically significant difference for complete suppression of urticaria (RR 0.91, 95% CI 0.78 to 1.06) or for 'good or excellent response' (RR 1.04, 95% CI 0.64 to 1.71). For loratadine(10 mg) versus mizolastine (10 mg) (intermediate-term), no statistically significant difference was seen for complete suppression of urticaria (RR 0.86, 95% CI 0.64 to 1.16) or for 'good or excellent response' (RR 0.88, 95% CI 0.55 to 1.42).Loratadine (10mg) versus emedastine (2mg) (intermediate-term) showed no statistically significant difference for complete suppression(RR 1.04, 95% CI 0.78 to 1.39) or for 'good or excellent response' (RR 1.09, 95% CI 0.96 to 1.24); the quality of the evidence was moderate for this comparison.No difference in short-term treatment was noted between loratadine (10mg) and hydroxyzine (25mg) in terms of complete suppression(RR 1.00, 95% CI 0.32 to 3.10).When desloratadine (5 to 20 mg) was compared with levocetirizine (5 to 20 mg), levocetirizine appeared to be the more effective (P value < 0.02).In a comparison of fexofenadine versus cetirizine, more participants in the cetirizine group showed complete suppression of urticaria(P value < 0.001).Adverse events leading to withdrawals were not significantly different in the following comparisons: cetirizine versus placebo at 10 mg and 20 mg (RR 3.00, 95% CI 0.68 to 13.22); desloratadine 5 mg versus placebo (RR 1.46, 95% CI 0.42 to 5.10); loratadine 10 mg versus mizolastine 10 mg (RR 0.38, 95% CI 0.04 to 3.60); loratadine 10mg versus emedastine 2mg (RR 1.09, 95%CI 0.07 to 17.14);cetirizine 10 mg versus hydroxyzine 25 mg (RR 0.78, 95% CI 0.25 to 2.45); and hydroxyzine 25 mg versus placebo (RR 3.64, 95%CI 0.77 to 17.23), all intermediate term.No difference was seen between loratadine 10 mg versus mizolastine 10 mg in the proportion of participants with at least 50%improvement in quality of life (RR 3.21, 95% CI 0.32 to 32.33).Authors' conclusions Although the results of our review indicate that at standard doses of treatment, several antihistamines are effective when compared with placebo, all results were gathered from a few studies or, in some cases, from single-study estimates. The quality of the evidence was affected by the small number of studies in each comparison and the small sample size for many of the outcomes, prompting us to downgrade the quality of evidence for imprecision (unless stated for each comparison, the quality of the evidence was low).No single H1-antihistamine stands out as most effective. Cetirizine at 10 mg once daily in the short term and in the intermediate term was found to be effective in completely suppressing urticaria. Evidence is limited for desloratadine given at 5 mg once daily in the intermediate term and at 20 mg in the short term. Levocetirizine at 5 mg in the intermediate but not short term was effective for complete suppression. Levocetirizine 20 mg was effective in the short term, but 10 mg was not. No difference in rates of withdrawal due to adverse events was noted between active and placebo groups. Evidence for improvement in quality of life was insufficient.

Therapy of chronic urticaria: a simple, modern approach

OBJECTIVE

To examine the available treatment choices for chronic spontaneous urticaria (CSU) and discuss a new paradigm for treating such patients.

DATA SOURCES

The literature regarding treatment is reviewed, including considerations of published guidelines. Attention is focused on the most recent evidence indicating particular efficacy of omalizumab.

RESULTS

Omalizumab has been found to have considerable efficacy in phase 2 and phase 3 trials in which more than 900 patients have been studied. A response rate of 65% is seen in patients resistant to antihistamines as well as to histamine2 blockers and leukotriene antagonists, and 40% of patients are completely free of hives as long as therapy is continued. In addition, serious adverse events have not been seen. Only cyclosporine can match this response rate (excluding steroids), but the adverse effect profile (blood pressure and renal function) is substantial by comparison. Double-blind, placebo-controlled studies of other agents often listed as alternatives are lacking (ie, whether their success rate exceeds the 25%-30% placebo response is uncertain). The mechanism by which omalizumab works in CSU is not clear because the response rate is unrelated to the autoimmune profile and can occur rapidly (ie, within a few days).

CONCLUSION

Omalizumab has exceptional efficacy for antihistamine-resistant CSU with an excellent adverse effect profile.