Conjunctival provocation test in diagnosis of peanut allergy in children.

BACKGROUND: Peanut allergy frequently causes severe allergic reactions. Diagnosis includes detection of IgE to peanuts in serum or by skin prick tests. While children may have allergic sensitization without having clinical peanut allergy, oral peanut challenge is often required for accurate diagnosis. The conjunctival provocation test is used for diagnosis and evaluation of treatment effect in inhalant allergies, but it has not been evaluated as a tool for diagnosing peanut allergy. OBJECTIVE: To investigate whether the conjunctival provocation tests may be feasible, accurate and safe in diagnosing clinically relevant peanut allergy in patients with suspected peanut allergy. METHODS: This cross-sectional case-control study in children with clinical or laboratory suspected peanut allergy included 102 children recruited from the regional paediatric departments and specialist practices during one year from April 2011. A peanut-tolerant control group of 28 children of similar age was recruited locally. A double-blind placebo-controlled conjunctival provocation test with peanut extract was performed in all children, while oral peanut provocation was performed as double-blind placebo-controlled challenge in children with suspected peanut allergy and as an open challenge in the control children. RESULTS: All 81 children with a positive double-blind placebo-controlled oral food challenge (OFC) also had a positive conjunctival provocation test. None of the children with negative conjunctival provocation test had a positive OFC. The sensitivity and the specificity of the conjunctival provocation test were 0.96 and 0.83, respectively. No children had severe adverse reaction caused by the conjunctival provocation test, whereas 23 children suffered an anaphylactic reaction to the OFC. CONCLUSION AND CLINICAL RELEVANCE: Conjunctival allergen challenge appears to be feasible, accurate and safe in diagnosing children referred for suspected peanut allergy.

Asthma and dietary intake: an overview of systematic reviews.

Epidemiological research on the relationship between diet and asthma has increased in the last decade. Several components found in foods have been proposed to have a series of antioxidant, anti-allergic and anti-inflammatory properties, which can have a protective effect against asthma risk. Several literature reviews and critical appraisals have been published to summarize the existing evidence in this field. In the context of this EAACI Lifestyle and asthma Task Force, we summarize the evidence from existing systematic reviews on dietary intake and asthma, using the PRISMA guidelines. We therefore report the quality of eligible systematic reviews and summarize the results of those with an AMSTAR score ≥32. The GRADE approach is used to assess the overall quality of the existing evidence. This overview is centred on systematic reviews of nutritional components provided in the diet only, as a way to establish what type of advice can be given in clinical practice and to the general population on dietary habits and asthma.

How to design and evaluate randomized controlled trials in immunotherapy for allergic rhinitis: an ARIA-GA(2) LEN statement.

Specific immunotherapy (SIT) is one of the treatments for allergic rhinitis. However, for allergists, nonspecialists, regulators, payers, and patients, there remain gaps in understanding the evaluation of randomized controlled trials (RCTs). Although treating the same diseases, RCTs in SIT and pharmacotherapy should be considered separately for several reasons, as developed in this study. These include the severity and persistence of allergic rhinitis in the patients enrolled in the study, the problem of the placebo, allergen exposure (in particular pollen and mite), the analysis and reporting of the study, the level of symptoms of placebo-treated patients, the clinical relevance of the efficacy of SIT, the need for a validated combined symptom-medication score, the differences between children and adults and pharmacoeconomic analyses. This statement reviews issues raised by the interpretation of RCTs in sublingual immunotherapy. It is not possible to directly extrapolate the rules or parameters used in medication RCTs to SIT. It also provides some suggestions for the research that will be needed. Interestingly, some of the research questions can be approached with the available data obtained from large RCTs.

A case-control study of the relation between plasma selenium and asthma in European populations: a GAL2EN project.

BACKGROUND: There is evidence that selenium levels are relatively low in Europe and may be falling. Low levels of selenium or low activity of some of the enzymes dependent on selenium have been associated with asthma. METHODS: The GA(2)LEN network has organized a multicentre case-control study in Europe to assess the relation of plasma selenium to asthma. The network compared 569 cases in 14 European centres with a diagnosis of asthma and reporting asthma symptoms in the last 12 months with 576 controls from the same centres with no diagnosis of asthma and no asthmatic symptoms in the last 12 months. RESULTS: All cases and controls were selected from the same population defined by age and place of residence. Mean plasma selenium concentrations among the controls ranged from 116.3 microg/l in Palermo to 67.7 microg/l in Vienna and 56.1 microg/l among the children in Oslo. Random effects meta-analysis of the results from the centres showed no overall association between asthma and plasma selenium [odds ratio (OR)/10 microg/l increase in plasma selenium: 1.04; 95% confidence interval (CI): 0.89-1.21] though there was a significantly protective effect in Lodz (OR: 0.48; 95% CI: 0.29-0.78) and a marginally significant adverse effect in Amsterdam (OR: 1.68; 95% CI: 0.98-2.90) and Ghent (OR: 1.35; 95% CI: 1.03-1.77). CONCLUSION: This study does not support a role for selenium in protection against asthma, but effect modification and confounding cannot be ruled out.

Respiratory virus infections and aeroallergens in acute bronchial asthma.

Two hundred and fifty six attacks of acute bronchial asthma occurring in 169 children aged over 2 years were studied during a two year period. More attacks occurred during spring and autumn than at other times of the year. In 73 patients (29%) a respiratory virus infection was diagnosed, with the same seasonal variation as the asthmatic attacks. Most of the virus infections were caused by rhinovirus (45%) and respiratory syncytial virus (19%). There was no significant correlation between asthmatic attacks in patients with birch pollen, grass pollen, or Cladosporium herbarum allergy and counts of the respective pollen or spores in the air. More seasonal attacks occurred in patients with cladosporium allergy than in patients without cladosporium allergy but there was no seasonal variation among birch or grass pollen allergic patients. Information about exposure to animals was obtained in only 12% of attacks occurring in 121 patients with allergy to animal dander. The single precipitating factor most frequently associated with acute asthma was respiratory virus infection.