Dietary intervention for preventing food allergy in children

A systematic review of infant feeding food allergy prevention guidelines - can we AGREE?

Food allergy is a significant issue worldwide, particularly in Westernised countries. There is no clear explanation why food allergy appears to have increased so rapidly in recent years, particularly in young children, hence ongoing research to identify effective primary prevention strategies. Food allergy prevention guidelines for health professionals have been developed based on existing clinical trial evidence for effective translation and implementation. As these guidelines underpin clinical practice, it is important to ensure robust processes of development. We conducted a systematic review to identify food allergy prevention guidelines for health professional use; to compare the recommendations made by the identified guideline documents; and to assess the quality of the identified guideline documents. We searched Medline, EMBASE, CINAHL, Scopus, Global Health and Guidelines International Network for the period 1990 to 13 August 2019, to identify articles referring to English-language food allergy prevention guidelines or the guidelines themselves. A grey literature search of Google Scholar and reference checking was also undertaken. The guidelines were compared for recommendation similarities and differences. An Appraisal Guidelines for Research and Evaluation (AGREE II) appraisal was undertaken to assess guideline quality. The electronic database search yielded 1121 publications and reference checking identified an additional 16 publications. After title, abstract and full text screening, data extraction was undertaken on 156 publications and with additional reference checking, 28 food allergy prevention guidelines and advice documents were identified. Comparison of the recommendations within the guidelines and advice documents indicated the greatest variation in recommendations related to exclusive breastfeeding and timing of solid food introduction. Eight of the 10 guidelines and none of the 18 advice documents met the quality threshold set by the reviewers. Overall, documents specifically termed "guidelines" scored better than advice documents when assessed using the AGREE II tool. Variation in recommendations may create confusion for health professionals and result in inconsistent advice being provided to parents, and less translation of the evidence into actual food allergy reduction in the population. Appraisal using the AGREE II tool identified that there is considerable room for improvement in the development of guidelines and advice documents for food allergy prevention. The AGREE II appraisal identified common areas of poorer quality development and/or documentation of processes to inform future guideline development. Based on this study, we recommend the use of validated guideline development tools, to direct food allergy prevention guideline review or development. Use of the AGREE II tool, to direct the review and development of guidelines, is very likely to improve guideline quality.

Asian children living in Australia have a different profile of allergy and anaphylaxis than Australian-born children: A State-wide survey

BACKGROUND

Asian children born in Australia have higher rates of eczema and nut allergy than non-Asian children. However, it is not known whether this country of birth differential exists for other allergies or anaphylaxis risk.

OBJECTIVE

We investigated the influence of maternal and child's country of birth on the prevalence of parent-reported eczema, asthma, food allergy and being diagnosed by a doctor as being "at risk of anaphylaxis."

METHODS

We assessed the relationship between mother and child country of birth and allergies using the 2010 School Entrant Health Questionnaire, completed for 57 005 5-year old children (85.8% response rate) in Victoria, Australia. Analyses were conducted using logistic regression with results presented as odds ratios (OR) with 95% confidence intervals (CIs).

RESULTS

Children born in Australia to Asian-born mothers were more likely to have parent-reported food allergy (OR 2.33, 95%CI 1.96-2.77) and eczema (OR 2.04, 95%CI 1.73-2.41), but not more likely to have asthma (OR 0.87, 95% CI 0.74-1.02) than non-Asian children. By contrast, children born in Asia who subsequently migrated to Australia had a lower risk of food allergy (OR 0.33, 95%CI 0.20-0.55), eczema (OR 0.37, 95%CI 0.24-0.57) and asthma (OR 0.29, 95% CI 0.21-0.40). Patterns of anaphylaxis risk differed depending on the trigger. Compared with Australian-born non-Asian children, Australian-born Asian children were more likely to be diagnosed as being at risk of both food-induced and non-food-induced anaphylaxis. For children born in Asia, risk was lower for anaphylaxis to milk, peanut and tree nuts compared to non-Asian children, but higher for soy, wheat and non-food triggers.

CONCLUSIONS AND CLINICAL RELEVANCE

Patterns of allergy/anaphylaxis risk and their triggers differed according to both ethnicity and country of birth, suggesting a gene-environment factor is in play. The difference in patterns for asthma compared with other atopic diseases is surprising and warrants further exploration.