Evaluation of desloratadine on conjunctival allergen challenge-induced ocular symptoms

Sublingual immunotherapy for pediatric allergic conjunctivitis: a meta-analysis of randomized controlled trials

BACKGROUND

Allergic conjunctivitis (AC) is a common chronic condition, especially in children. Ocular symptoms are often overlooked during treatment of allergic rhinoconjunctivitis (ARC). Pediatric ARC can be effectively treated using sublingual immunotherapy (SLIT), which is a guideline-recommended safe treatment approach. However, the therapeutic efficacy of SLIT in terms of ameliorating eye symptoms has not been effectively evaluated.

METHODS

We performed a meta-analysis of randomized controlled trials (RCTs) evaluating the use of SLIT for infants, children, and adolescents (aged from 3 to 18 years) with AC or ARC. We searched the Cochrane Library database, EMBASE, and Medline from November 1990 to 2017 to find papers dealing with the effects of SLIT on pediatric AC or ARC. We used standardized mean differences (SMDs) to assess therapeutic effects, employing a random effects model. Subgroup and sensitivity analyses were also conducted. The I² metric was used to evaluate heterogeneity.

RESULTS

In total, 13 clinical RCTs were included in our meta-analysis. SLIT reduced ocular symptoms to a level below that of controls (SMD = -0.21; 95% confidence interval [CI], -0.41 to -0.01; p = 0.04; I² = 55%). Notably, on subgroup analysis, SLIT clearly reduced pollen-induced pediatric AC (SMD = -0.36; 95% CI, -0.53 to -0.19; p < 0.0001; I² = 25%) but not mite-induced AC (SMD = 0.20; 95% CI, -0.20 to 0.60; p = 0.34; I² = 46%).

CONCLUSION

SLIT relieved ocular symptoms in children with ARC or AC. To confirm these results, future meta-analyses should evaluate high-quality, large-scale population-based trials.

Antihistamine therapy in allergic rhinitis

Antihistamines have long been a mainstay in the therapy for allergic rhinitis. Many different oral antihistamines are available for use, and they are classified as first generation or second generation based on their pharmacologic properties and side-effect profiles. The recent introduction of intranasal antihistamines has further expanded the role of antihistamines in the treatment of allergic rhinitis. Certain patient populations, such as children and pregnant or lactating women, require special consideration regarding antihistamine choice and dosing as part of rhinitis therapy.

Sublingual immunotherapy for treating allergic conjunctivitis

BACKGROUND

Allergic ocular symptoms, although frequently trivialised, are common and represent an important comorbidity of allergic rhinitis. Sublingual Immunotherapy (SLIT) is an effective and well-tolerated treatment for allergic rhinitis, but its effects on symptoms of ocular allergy have not been well established.

OBJECTIVES

To evaluate the efficacy of SLIT compared with placebo for reductions in ocular symptoms, topical ocular medication requirements and conjunctival immediate allergen sensitivity.

SEARCH STRATEGY

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 1), MEDLINE (January 1950 to January 2011), EMBASE (January 1980 to January 2011), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2011), Web of Science (January 1970 to January 2011), Biosis Previews, (January 1979 to January 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (January 2011), ClinicalTrials.gov (www.clinicaltrials.gov) (January 2011), the Australian New Zealand Clinical Trials Registry (ANZCTR) (www.actr.org.au) (July 2010), SCOPUS (November 2008) and the UK Clinical Trials Gateway (January 2010). There were no language or date restrictions in the search for trials. All electronic databases except for SCOPUS, the UK Clinical Trials Gateway and ANZCTR were last searched on 19 January 2011.

SELECTION CRITERIA

Randomised controlled trials (RCTs), double-masked and placebo controlled, which evaluated the efficacy of SLIT in patients with symptoms of allergic rhinoconjunctivitis (ARC) or allergic conjunctivitis (AC).

DATA COLLECTION AND ANALYSIS

The primary outcome was the total ocular symptom scores. Secondary endpoints included individual ocular symptom scores (such as itchy eyes, red eyes, watery eyes, swollen eyes), ocular medication scores (eye drops) and conjunctival immediate allergen sensitivity (CIAS). Data were analysed and reported as standardised mean differences (SMDs) using Review Manager software.

MAIN RESULTS

Forty-two trials (n = 3958 total participants; n= 2011 SLIT and n = 1947 placebo) had available data to evaluate the efficacy of SLIT on AC and were included in the meta-analyses. Heterogeneity among studies (I(2) statistic) was around 50% or below for all endpoints. Sublingual immunotherapy induced a significant reduction in both total ocular symptom scores (SMD -0.41; 95% confidence interval (CI) -0.53 to -0.28; P < 0.00001; I(2) = 59%) and individual ocular symptom scores for red eyes (SMD -0.33; 95% CI -0.45 to -0.22; P < 0.00001; I(2) = 27%), itchy eyes (SMD -0.31; 95% CI -0.42 to -0.20; P < 0.00001; I(2) = 46%) and watery eyes (SMD -0.23; 95% CI -0.34 to -0.11; P < 0.0001; I(2) = 42%) compared to placebo. Those participants having active treatment showed an increase in the threshold dose for the conjunctival allergen provocation test (SMD 0.35; 95% CI 0.00 to 0.69; P = 0.05; I(2) = 43%). No significant reduction was observed in ocular eye drops use (SMD -0.10; 95% CI -0.22 to 0.03; P = 0.13; I(2) = 34%).

AUTHORS' CONCLUSIONS

Overall, SLIT is moderately effective in reducing total and individual ocular symptom scores in participants with ARC and AC. There were however some concerns about the overall quality of the evidence-base, this relating to inadequate descriptions of allocation concealment in some studies, statistical heterogeneity and the possibility of publication bias. There is a need for further large rigorously designed studies that study long-term effectiveness after discontinuation of treatment and establish the cost-effectiveness of SLIT.

Developments in the field of allergy in 2009 through the eyes of Clinical and Experimental Allergy

In 2009 the journal published in the region of 200 papers including reviews, editorials, opinion pieces and original papers that ran the full gamut of allergic disease. It is instructive to take stock of this output to determine patterns of interest and where the cutting edge lies. We have surveyed the field of allergic disease as seen through the pages of Clinical and Experimental Allergy (CEA) highlighting trends, emphasizing notable observations and placing discoveries in the context of other key papers published during the year. The review is divided into similar sections as the journal. In the field of Asthma and Rhinitis CEA has contributed significantly to the debate about asthma phenotypes and expressed opinions about the cause of intrinsic asthma. It has also added its halfpennyworth to the hunt for meaningful biomarkers. In Mechanisms the considerable interest in T cell subsets including Th17 and T regulatory cells continues apace and the discipline of Epidemiology continues to invoke a steady stream of papers on risk factors for asthma with investigators still trying to explain the post-second world war epidemic of allergic disease. Experimental Models continue to make important contributions to our understanding of pathogenesis of allergic disease and in the Clinical Allergy section various angles on immunotherapy are explored. New allergens continue to be described in the allergens section to make those allergen chips even more complicated. A rich and vibrant year helpfully summarized by some of our associate editors.