Part II: Chronic Urticaria/Angioedema

A Comparative, Three-Arm, Randomized Clinical Trial to Evaluate the Effectiveness and Tolerability of Bilastine vs Fexofenadine vs Levocetirizine at the Standard Dose and Bilastine vs Fexofenadine at Higher Than the Standard Dose (Up-Dosing) vs Levocetirizine and Hydroxyzine (in Combination) in Patients with Chronic Spontaneous Urticaria

Introduction

Though second-generation antihistamines (SGAH) are first-line drugs in chronic spontaneous urticaria (CSU), 50% of patients do not respond to them. In such patients, guidelines recommend either up-dosing of SGAH or combination of different antihistamines. However, the studies comparing these treatment regimens are limited.

Methods

In this comparative, three-arm study, CSU patients were randomized to receive standard dose of either bilastine, fexofenadine, or levocetirizine for 2 weeks. After 2 weeks of treatment, non-responders received double dose of either bilastine or fexofenadine, while hydroxyzine 25 mg once daily was added in the levocetirizine group. Patients were primarily evaluated for improvement in CSU, quality of life, and somnolence.

Results

A total of 110 patients with CSU were recruited. At the end of 4 weeks, 33/39, 26/35, and 22/36 patients in the bilastine, fexofenadine, and levocetirizine groups showed improvement in urticaria symptoms. At week 2, there was no statistical difference in urticaria activity score (UAS7) improvement between any of the groups; however, at week 4, there was a statistical difference between the bilastine and levocetirizine groups (p<0.05). Somnolence was significantly lower in the bilastine group (p<0.05). Bilastine was statistically significant (p<0.05) in the improvement of quality of life as compared to both groups. No major adverse events were reported during study period; however, bilastine was associated with significantly lower levels of AEs compared to levocetirizine (p<0.05).

Conclusion

Two-fold up-dosing of bilastine improves CSU symptoms without compromising safety as compared to two-fold up-dosing of fexofenadine and combination of first- and second-generation antihistamines.

Food allergy in adults: an over- or underrated problem?

BACKGROUND

10% to 20% of the population sees itself as suffering from food allergy, yet genuine, immune-mediated food allergy is suspected by patients and their physicians far more often than it is actually shown to be present. The unfounded suspicion of an IgE-mediated food allergy can substantially impair a patient's quality of life through needless dietary restriction and the accompanying anxiety. On the other hand, an IgE-mediated food allergy that has gone undiagnosed or that has not been taken seriously can manifest suddenly with anaphylaxis, which may be life-threatening. The present study, carried out on a large cohort of patients, underscores the importance of differentiating IgE-mediated food allergy from other, nonallergic types of food reaction.

METHODS

419 patients that had been referred to our outpatient allergy clinic for suspected food allergies underwent a standardized allergological diagnostic evaluation, including thorough allergologic history-taking, IgE serology, and challenge tests when indicated.

RESULTS

214 patients (51.1%) were found to have an IgE-mediated food allergy. Almost half of these patients (24.3% of the overall group) had previously experienced food-induced anaphylaxis. In 205 patients (48.9%), however, an IgE-mediated food allergy was ruled out as far as possible.

CONCLUSION

Only a comprehensive allergological evaluation performed by an experienced allergologist in accordance with current guidelines can protect patients from the negative consequences of excessive concern about a nonexistent food allergy (e.g., needless dietary restriction) or, on the other hand, the negative consequences of inadequate attention to a genuine food allergy (anaphylaxis). A proper evaluation consists of detailed allergologic history-taking, skin tests, and challenge tests when indicated.

Non-sedating antihistamines in the treatment of chronic idiopathic urticaria using patient-reported outcomes

BACKGROUND

Chronic idiopathic urticaria (CIU) greatly impairs quality of life (QoL). Thus, patient-reported outcome (PRO) measures, using validated scoring instruments, are probably the most accurate tools available for assessing the efficacy of medications that treat CIU, such as second-generation antihistamines.

RESEARCH METHODS

A structured search of the MEDLINE database was conducted to identify English-language papers published between 1 January 1991 and 30 September 2007 on the treatment of CIU with the second-generation antihistamines cetirizine, desloratadine, fexofenadine, and levocetirizine, and their effects on patient-reported QoL. We used the following search terms alone or in combination: 'chronic idiopathic urticaria'; 'pruritus'; 'wheals'; 'hives'; 'second-generation antihistamines'; 'cetirizine'; 'desloratadine'; 'fexofenadine'; 'levocetirizine'; and 'quality of life'.

SCOPE

We evaluated the effects of second-generation antihistamines on the QoL of subjects with CIU using desloratadine as a treatment model. Desloratadine was selected because it is the most frequently assessed non-sedating second-generation antihistamine in QoL studies in patients with CIU.

FINDINGS

Desloratadine 5 mg QD improved QoL in numerous PRO studies. Treatment with desloratadine significantly (p < 0.05) lowered (better) scores in three studies (n = 364) that used validated dermatology-specific scoring instruments. Three 6-week double-blind, placebo-controlled trials (n = 553) found that desloratadine significantly (p < 0.05) improved patient-reported pruritus, sleep disruption, and interference with daily activities. Desloratadine was associated with a low incidence of adverse events and an overall tolerability profile similar to placebo.

LIMITATIONS

Limitations in this review include divergence in search practices that may lead to omission of relevant research, unintentional error in data transfer, inconsistency in quality of selected papers, and potential publication bias against papers that report results from small studies.

CONCLUSIONS

The favorable impact of second-generation antihistamines on the QoL of patients with CIU was demonstrated using desloratadine, the most frequently investigated drug in this field, as a treatment model.

Urticaria: its history-based diagnosis and etiologically oriented treatment

INTRODUCTION

The term "urticaria" refers to any of a group of distinct skin conditions that are characterized by itchy, wheal-and-flare skin reactions (hives). In spontaneous urticaria, the most common type, the hives seem to arise without provocation.

METHODS

Selective review of the literature, including current guidelines.

RESULTS

Spontaneous urticaria is divided into acute (lasting less than six weeks) and chronic types. The pathognomonic itching, hives, and angioedema arise by the same mechanism--cutaneous mast cell activation and release of histamine and other mediators of inflammation--in both acute and chronic urticaria, but these two disorders have different etiological profiles. The underlying cause of acute urticaria cannot be identified in about half of all cases. Chronic urticaria, which is much rarer, is usually caused by autoreactivity, chronic infection, or intolerance to food additives. If the condition persists after the underlying cause has been treated or eliminated, non-sedating antihistamines are the agents of first choice for symptomatic treatment.

DISCUSSION

Unlike acute urticaria, which is self-limited and should be treated symptomatically, chronic urticaria should be treated by the identification and elimination of underlying causes, which is usually curative.

Second-Generation Antihistamines

Antihistamines are useful medications for the treatment of a variety of allergic disorders. Second-generation antihistamines avidly and selectively bind to peripheral histamine H1 receptors and, consequently, provide gratifying relief of histamine-mediated symptoms in a majority of atopic patients. This tight receptor specificity additionally leads to few effects on other neuronal or hormonal systems, with the result that adverse effects associated with these medications, with the exception of noticeable sedation in about 10% of cetirizine-treated patients, resemble those of placebo overall. Similarly, serious adverse drug reactions and interactions are uncommon with these medicines. Therapeutic interchange to one of the available second-generation antihistamines is a reasonable approach to limiting an institutional formulary, and adoption of such a policy has proven capable of creating substantial cost savings. Differences in overall efficacy and safety between available second-generation antihistamines, when administered in equivalent dosages, are not large. However, among the antihistamines presently available, fexofenadine may offer the best overall balance of effectiveness and safety, and this agent is an appropriate selection for initial or switch therapy for most patients with mild or moderate allergic symptoms. Cetirizine is the most potent antihistamine available and has been subjected to more clinical study than any other. This agent is appropriate for patients proven unresponsive to other antihistamines and for those with the most severe symptoms who might benefit from antihistamine treatment of the highest potency that can be dose-titrated up to maximal intensity.

Chronic idiopathic urticaria for the generalist

Chronic idiopathic urticaria (CIU) manifests as frequently occurring, short-lived wheals, surrounded by a bright-red flare, and often accompanied by angioedema. The cause of CIU is undefined and its diagnosis requires exclusion of other conditions with somewhat similar symptoms. Recent evidence has indicated that IgG autoantibodies directed against high-affinity IgE receptors (FcepsilonRI) may be involved in the pathophysiology of CIU. Following the release of mast cell or basophil-derived histamine, this mediator binds to H(1) and H(2) receptors, leading to vasodilatation and increased vascular permeability. Individuals with CIU may be unable to conduct normal daily activities; therefore, prompt initiation of effective treatment is essential. General management of patients should include avoidance of substances likely to trigger or intensify episodes. Treatment with antihistamines is the mainstay of pharmacotherapy for CIU. Selection of antihistamine therapy for patients with CIU should be based on the following key properties: (1) proven clinical efficacy in providing a high rate of symptom improvement, (2) rapid onset of action and a long-lasting response, and (3) an excellent safety profile and a high degree of tolerability. The benefit of some second-generation antihistamines is limited by sedation, drug-drug interactions, or a variable therapeutic response. The H(1)-receptor antagonist desloratadine is a new, once-daily treatment option that is potent and nonsedating, and has a low potential for drug-drug interactions. Desloratadine has a rapid onset of action and has been shown to effectively and safely reduce pruritus and the number and size of hives in patients with CIU, leading to improvements in quality of life.

Laboratory tests and identified diagnoses in patients with physical and chronic urticaria and angioedema: A systematic review

BACKGROUND

The value of laboratory tests in chronic urticaria is still controversial.

OBJECTIVE

Our aim was to assess this value in clinical studies, and to identify factors explaining the variation in the number of identified causes.

METHODS

A total of 4 electronic databases were searched, and a manual literature search was performed. Only unselected patient series with more than 50 adult patients were included. From each included study predefined items were recorded to assess their quality (consecutive patients, use of standardized diagnostic criteria) and validity (follow-up, assessment of treatment effects, level of evidence).

RESULTS

A total of 29 studies were included, involving 6462 patients. The verification of the validity of the results and the level of evidence of the included studies were limited.

CONCLUSION

No relationship between the number of identified diagnoses and the number of performed laboratory tests, the different settings, the study design, or the publication period was found. On the basis of this systematic review and the relevant literature, a clinical guideline in the form of a flowchart is presented.