The parent-reported prevalence and management of peanut and nut allergy in school children in the Australian Capital Territory

Oral Food Challenge in Children with Tree Nut and Peanut Allergy: The Predictive Value of Diagnostic Tests

Food allergy (FA) affects approximately 6-8% of young children, with a peak prevalence at approximately one year of age. Tree nut and peanut allergies are among the main causes of anaphylaxis in the world. The gold standard for the diagnosis of FAs is the oral food challenge (OFC). Other diagnostic tests used in the clinical practice are skin prick tests (SPTs) and laboratory tests to measure out the presence of serum specific IgE (sIgE). In this narrative review, we collect the current evidence of the predictive value (PV) of SPTs and sIgE for the outcome of the OFCs. In literature, data are conflicting as to whether increasing sIgE concentration and wheal size in SPTs correlate with OFC outcomes. Most studies included in our review have shown that in vivo and in vitro tests may predict OFC outcomes with variable PV, but data are not conclusive; therefore, the OFC currently remains the gold standard for FA diagnosis.

Breastfeeding and risk of food allergy and allergic rhinitis in offspring: a systematic review and meta-analysis of cohort studies

The association between breastfeeding and the occurrence of allergic rhinitis (AR) and food allergy (FA) in offspring remains inconclusive. This review aims to comprehensively explore the potential relationships between various patterns and durations of breastfeeding and allergic diseases in offspring. We systematically searched PubMed, EMBASE, Cochrane, WOS databases, and Google Scholar for observational studies published up to March 30, 2023, that investigated the link between breastfeeding and allergies in offspring. The quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS) and Joanna Briggs Institute (JBI). Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated employing an appropriate model based on the degree of heterogeneity. A total of 68 studies, encompassing 772,142 children, were ultimately included. The findings indicated that breastfeeding for more than 6 months was associated with a reduced risk of AR (OR = 0.88, 95% CI: 0.79 to 0.98) but posed a risk for FA (OR = 1.69, 95% CI: 1.27 to 2.25). Exclusive breastfeeding exhibited a protective effect against AR (OR = 0.94, 95% CI: 0.90 to 0.97), whereas non-breastfeeding was identified as a risk factor for AR (OR = 1.48; 95% CI: 1.03 to 2.12). No significant association was observed between breastfeeding patterns and FA.

CONCLUSION

Breastfeeding for more than 6 months proves to be an effective preventive measure against AR. However, large prospective high-quality studies are needed to investigate the potential risk of FA in children with prolonged breastfeeding.

WHAT IS KNOWN

• The impact of breastfeeding on allergic rhinitis and food allergy in offspring is controversial. • Previous meta-analyses fail to prove the effect of breastfeeding on food allergy in offspring of all ages.

WHAT IS NEW

• Breastfeeding for more than 6 months proves to be an effective preventive measure against AR. However, it potentially elevates the risk of FA in children. Non-breastfeeding is linked to an increased risk of AR in children, but there is no evidence of an association between breastfeeding patterns and FA in children. • The impact of breastfeeding on allergic rhinitis and food allergy in offspring may vary with the time and pattern of breastfeeding.

Prevalence of asthma and allergic disorders in regional, rural, and indigenous children aged 6-8 years in Tasmania

Objective: Asthma and allergic diseases are poorly described in rural areas. The objective of this study was, therefore, to determine the prevalence of wheezing, asthma, and other allergic disorders among children living in regional and rural Tasmania. Methodology: Data from a cross-sectional survey using standardized questionnaires of asthma, allergic conditions and food allergies were collected from 39 primary schools across North West Tasmania. We enrolled 1075 children between 6 and 8 years. The main outcomes were prevalences of wheezing, asthma, and other allergic disorders further stratified by sex and indigenous status. Results: Baseline characteristics were as follows: median age 8.1 years (IQR: 7.6, 8.7) with equal sex distribution, most (80.1%) attended public schools and 11.0% identified as indigenous. We report prevalences of current wheezing (22.7%), allergic rhinoconjunctivitis (16.3%) and atopic eczema (16.6%), with higher prevalences among boys (except eczema). Food allergies were reported in 8.6% and food-related anaphylaxis in 1.6% of the sample. Indigenous children had significantly higher prevalence of current wheezing (indigenous 31.1% versus non-indigenous 21.6%; p = 0.02). Further, children with current wheezing and no asthma diagnosis, had similar prevalence of other atopic diseases (hayfever 31.4%, eczema 44.0%, and food reaction 23.2%) compared with diagnosed asthmatics, although likely shared the illness. Conclusions: Childhood asthma is more prevalent in regional Tasmania compared with national estimates, especially among indigenous children. This appears not to be driven by an allergic response. Also, a significant proportion of children are likely to have undiagnosed asthma which has implications for rural health service delivery.

Nut allergy prevalence and differences between Asian-born children and Australian-born children of Asian descent: a state-wide survey of children at primary school entry in Victoria, Australia

BACKGROUND

Asian infants born in Australia are three times more likely to develop nut allergy than non-Asian infants, and rates of challenge-proven food allergy in infants have been found to be unexpectedly high in metropolitan Melbourne. To further investigate the risk factors for nut allergy, we assessed the whole-of-state prevalence distribution of parent-reported nut allergy in 5-year-old children entering school.

METHODS

Using the 2010 School Entrant Health Questionnaire administered to all 5-year-old children in Victoria, Australia, we assessed the prevalence of parent-reported nut allergy (tree nut and peanut) and whether this was altered by region of residence, socio-economic status, country of birth or history of migration. Prevalence was calculated as observed proportion with 95% confidence intervals (CI). Risk factors were evaluated using multivariable logistic regression and adjusted for appropriate confounders.

RESULTS

Parent-reported nut allergy prevalence was 3.1% (95% CI 2.9-3.2) amongst a cohort of nearly 60 000 children. It was more common amongst children of mothers with higher education and socio-economic index and less prevalent amongst children in regional Victoria than in Melbourne. While children born in Australia to Asian-born mothers (aOR 2.67, 95% CI 2.28-3.27) were more likely to have nut allergy than non-Asian children, children born in Asia who subsequently migrated to Australia were at decreased risk of nut allergy (aOR 0.1, 95% CI 0.03-0.31).

CONCLUSION

Migration from Asia after the early infant period appears protective for the development of nut allergy. Additionally, rural regions have lower rates of nut allergy than urban areas.

Breastfeeding and asthma and allergies: a systematic review and meta-analysis

AIM

To systematically review the association between breastfeeding and childhood allergic disease.

METHODS

Predetermined inclusion/exclusion criteria identified 89 articles from PubMed, CINAHL and EMBASE databases. Meta-analyses performed for categories of breastfeeding and allergic outcomes. Meta-regression explored heterogeneity.

RESULTS

More vs. less breastfeeding (duration) was associated with reduced risk of asthma for children (5-18 years), particularly in medium-/low-income countries and with reduced risk of allergic rhinitis ≤5 years, but this estimate had high heterogeneity and low quality. Exclusive breastfeeding for 3-4 months was associated with reduced risk of eczema ≤2 years (estimate principally from cross-sectional studies of low methodological quality). No association found between breastfeeding and food allergy (estimate had high heterogeneity and low quality). Meta-regression found differences between study outcomes may be attributable to length of breastfeeding recall, study design, country income and date of study inception. Some of the protective effect of breastfeeding for asthma may be related to recall bias in studies of lesser methodological quality.

CONCLUSION

There is some evidence that breastfeeding is protective for asthma (5-18 years). There is weaker evidence for a protective effect for eczema ≤2 years and allergic rhinitis ≤5 years of age, with greater protection for asthma and eczema in low-income countries.

The Prevalence of Tree Nut Allergy: A Systematic Review

Tree nuts are one of the most common foods causing acute allergic reactions and nearly all tree nuts have been associated with fatal allergic reactions. Despite their clinical importance, tree nut allergy epidemiology remains understudied and the prevalence of tree nut allergy in different regions of the world has not yet been well characterised. We aimed to systematically review the population prevalence of tree nut allergy in children and adults. We searched three electronic databases (OVID MEDLINE, EMBASE and PubMed) from January 1996 to December 2014. Eligible studies were categorised by age, region and method of assessment of tree nut allergy. Of the 36 studies identified most were in children (n = 24) and from Europe (n = 18), UK (n = 8) or USA (n = 5). Challenge-confirmed IgE-mediated tree nut allergy prevalence was less than 2 % (although only seven studies used this gold standard) while probable tree nut allergy prevalence ranged from 0.05 to 4.9 %. Prevalence estimates that included oral allergy syndrome (OAS) reactions to tree nut were significantly higher (8-11.4 %) and were predominantly from Europe. Prevalence of individual tree nut allergies varied significantly by region with hazelnut the most common tree nut allergy in Europe, walnut and cashew in the USA and Brazil nut, almond and walnut most commonly reported in the UK. Monitoring time trends of tree nut allergy prevalence (both overall and by individual nuts) as well as the prevalence of OAS should be considered given the context of the overall recent rise in IgE-mediated food allergy prevalence in the developed world.

Infant Feeding Practices and Nut Allergy over Time in Australian School Entrant Children

Aim. To measure the association between infant feeding practices and parent-reported nut allergy in school entrant children. Method. The Kindergarten Health Check Questionnaire was delivered to all 110 Australian Capital Territory (ACT) primary schools between 2006 and 2009. Retrospective analyses were undertaken of the data collected from the kindergarten population. Results. Of 15142 children a strong allergic reaction to peanuts and other nuts was reported in 487 (3.2%) and 307 (3.9%), children, respectively. There was a positive association between parent reported nut allergy and breast feeding (OR = 1.53; 1.11–2.11) and having a regular general practitioner (GP) (OR = 1.42; 1.05–1.92). A protective effect was found in children who were fed foods other than breast milk in the first six months (OR = 0.71; 0.60–0.84). Conclusion. Children were at an increased risk of developing a parent-reported nut allergy if they were breast fed in the first six months of life.

Prevalence of challenge-proven IgE-mediated food allergy using population-based sampling and predetermined challenge criteria in infants

BACKGROUND

Several indicators suggest that food allergy in infants is common and possibly increasing. Few studies have used oral food challenge to measure this phenomenon at the population level.

OBJECTIVE

To measure the prevalence of common IgE-mediated childhood food allergies in a population-based sample of 12-month-old infants by using predetermined food challenge criteria to measure outcomes.

METHODS

A sampling frame was used to select recruitment areas to attain a representative population base. Recruitment occurred at childhood immunization sessions in Melbourne, Australia. Infants underwent skin prick testing, and those with any sensitization (wheal size ≥ 1 mm) to 1 or more foods (raw egg, peanut, sesame, shellfish, or cow's milk) were invited to attend an allergy research clinic. Those who registered a wheal size ≥ 1 mm to raw egg, peanut, or sesame underwent oral food challenge.

RESULTS

Amongst 2848 infants (73% participation rate), the prevalence of any sensitization to peanut was 8.9% (95% CI, 7.9-10.0); raw egg white, 16.5% (95% CI, 15.1-17.9); sesame, 2.5% (95% CI, 2.0-3.1); cow's milk, 5.6% (95% CI, 3.2-8.0); and shellfish, 0.9% (95% CI, 0.6-1.5). The prevalence of challenge-proven peanut allergy was 3.0% (95% CI, 2.4-3.8); raw egg allergy, 8.9% (95% CI, 7.8-10.0); and sesame allergy, 0.8% (95% CI, 0.5-1.1). Oral food challenges to cow's milk and shellfish were not performed. Of those with raw egg allergy, 80.3% could tolerate baked egg.

CONCLUSION

More than 10% of 1-year-old infants had challenge-proven IgE-mediated food allergy to one of the common allergenic foods of infancy. The high prevalence of allergic disease in Australia requires further investigation and may be related to modifiable environmental factors.

Are peanut allergies a concern for using peanut-based formulated foods in developing countries?

BACKGROUND

Peanut allergy is relatively common among children in developed countries and may have severe outcomes, including anaphylaxis. However, few data about peanut allergy in developing countries are available. Meanwhile, formulated foods with peanuts as a major ingredient are being promoted to prevent and control malnutrition in developing countries.

OBJECTIVE

The objectives of the paper are to review the existing epidemiologic data about peanut allergy, to determine whether the prevalence of peanut allergy is lower in developing countries, and to explore the possible reasons for onset of peanut allergy.

METHODS

Publications relevant to peanut allergy were searched via Pubmed, and prevalence and etiological factors of peanut allergy were reviewed.

RESULTS

Data about peanut allergy were scarce in most developing countries. The existing data support the conclusion that peanut allergy is not as common in developing countries as in developed countries and may not be a major concern for programs promoting formulated food containing peanuts for control of malnutrition. However, plans for treatment of individuals with peanut allergy could be incorporated into these formulated food supplementation programs. A few risk factors (late introduction of peanuts to children, peanut processing technology, non-oral peanut exposure, and maternal peanut exposure during pregnancy and lactation) have been hypothesized to be associated with peanut allergy. However, more conclusive data are needed to verify or disprove these hypotheses.

CONCLUSIONS

Peanut allergy is not as common in developing countries as in developed countries and may not be a major concern for programs promoting formulated food containing peanuts for control of malnutrition. However, more research about prevalence of peanut allergy is warranted in developing countries.