Severe peanut allergy in Australian children

Allergic reaction to peanuts: can we predict reaction severity in the wild?

Peanut allergy (PNA) is the main cause of food-induced anaphylaxis. Severe allergic reactions are more likely to occur in older patients and those with underlying asthma. Skin prick testing and measuring serum-specific IgE and recombinant peanut protein levels have been shown to be useful in the diagnosis of PNA and prediction of reactivity, but these tests are less consistent and reliable in terms of predicting the severity of reactions. Recent research has examined the role of biological mediators in allergic reactions such as platelet-activating factor. These may provide a future tool in predicting those at risk of severe reactions. Currently, there are no parameters that can predict with certainty those at risk of anaphylaxis, and management of PNA should continue to focus on patient and family education.

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.

A qualitative study of families of a child with a nut allergy

OBJECTIVES

The aim of this study was to explore, using qualitative methods, the experiences of children and their parents living with nut allergy.

METHODS

Children with a confirmed diagnosis of peanut allergy were identified from a database of patients maintained at an allergy clinic at a large teaching hospital. Interviews with 26 families were conducted involving 11 children, 25 mothers and 12 fathers.

RESULTS

The diagnosis of nut allergy signalled a critical transition-or biographical disruption-in the life of the family. Parents took on the role of 'alert assistant' and sought to create 'safe places' where nuts were not permitted, but often struggled when outside the home environment. The option of 'passing as normal', often used by people with a chronic illness to avoid stigma, was not available to them. Consequently, parents often reported being treated as faddy, demanding, and neurotic, and children suffered from teasing and exclusion. The social consequences of nut allergy were worsened by poor labelling and control of foods and products containing nuts.

DISCUSSION

In many ways, nut allergy may be considered a form of disability, because it imposes social barriers on participating fully in society.

Prediction of anaphylaxis during peanut food challenge: usefulness of the peanut skin prick test (SPT) and specific IgE level

Cutoffs (decision points) of the peanut skin prick test (SPT) and specific IgE level for predicting peanut allergy have been proposed. It is not known whether decision points indicating a significant risk of severe reactions on challenge differ from those indicating probable allergy. We aimed at determining the usefulness of allergy tests for predicting the risk of anaphylaxis on challenge following the ingestion of up to 12 g of peanut in peanut-sensitized children. Children attending the Allergy Clinic who had a positive peanut SPT and completed open-label in-hospital peanut challenges were included. The challenge protocol provided for challenges to be continued beyond initial mild reactions. Eighty-nine in-hospital peanut challenges were performed. Thirty-four were excluded as the challenge was not completed, leaving 55 for analysis. Children who completed the challenge and did not react (n = 28) or reacted without anaphylaxis (n = 6) represented the comparison group (n = 34). The study group comprised 21 children whose challenge resulted in anaphylaxis. The mean peanut SPT wheal size and specific IgE level were associated with the severity of reactions on challenge. Among the 21 children, who developed anaphylaxis, in only 3 cases was anaphylaxis the initial reaction. Unexpectedly, a history of anaphylaxis was not predictive of anaphylaxis on challenge. Anaphylaxis developed at cumulative doses of peanut ranging from 0.02 to 11.7 g. Provided that a fixed amount of peanut is ingested, available tests for peanut allergy may assist in predicting the risk of anaphylaxis during challenge in peanut-sensitized children.

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

AIM

To describe parent-reported prevalence and management of peanut and nut allergy in school entrant children.

METHOD

A population-based, cross-sectional study in the Australian National Capital.

RESULTS

Out of 3851 children, parents reported 127 had a strong allergic reaction to peanuts and 19 to other nuts ever. Nut allergy ever prevalence was 3.8% (95% confidence interval 3.2-4.4%), and of peanut allergy ever 3.3% (2.8-3.9%). Children with nut allergy were more likely to have a general practitioner (odds ratio 2.64, 1.16-6.03), hay fever (3.78, 2.67-5.36), eczema (4.54, 3.15-6.56) and wheeze in the last 12 months (3.19, 2.22-4.59) and have been breastfed (2.68, 1.26-5.77) than those who did not. At follow up of 109 children with parent-reported allergy (75% response), 70% had diagnostic test-confirmed sensitisation, 32% had been prescribed an adrenalin autoinjector (6% had used one) and 46% were not eating peanut. Increasing severity of reported symptoms following consumption of peanut was associated with an increasing likelihood of recommended management. Based on parent report, the projected estimated diagnostic test-confirmed prevalence of peanut sensitisation was 2.4% (1.9%, 3.0%) for the entire sample.

CONCLUSION

Among a highly representative sample of children at school entry, 1 in 30 parents reported their child to have a strong allergic reaction to nuts and over 1 in 50 are estimated to have diagnostic test-confirmed peanut sensitisation, based on parent report.

Paediatric food allergy trends in a community-based specialist allergy practice, 1995-2006

OBJECTIVE

To examine changing demand for specialist food allergy services for children aged 0-5 years over the 12 years from 1995 to 2006 as an index of changing prevalence.

DESIGN, SETTING AND PARTICIPANTS

Retrospective analysis of the records of 1489 children aged 0-5 years referred to a community-based specialist allergy practice in the Australian Capital Territory (population, about 0.33 million).

MAIN OUTCOME MEASURES

Trends in demand for assessment for food allergy, dietary triggers and severity over 12 years, compared with Australian hospital morbidity data.

RESULTS

47% (697/1489) of 0-5 year-old children seen in private practice had food allergy (175 with food-associated anaphylaxis), most commonly to peanut, egg, cows milk and cashew. Over 12 years, the number of children in this age group evaluated each year increased more than fourfold, from 55 cases in 1995 to 240 in 2006. There was no change in the proportion diagnosed with allergic rhinitis in 1995 and 2006 (14.5% and 13.3%, respectively), urticaria (14.5% and 12.9%) or atopic eczema (54.5% and 57.0%). By contrast, the proportion with asthma dropped from 33.7% in 1995 to 12.5% in 2006 and the number with food allergy increased 12-fold, from 11 to 138 patients (and from 20.0% to 57.5% of children seen) The number with food anaphylaxis increased from five to 37 children (9.0% to 15.4%) over the same period. There were similar trends in age-adjusted Australian hospital admission rates for anaphylaxis in children aged 0-4 years, which increased from 39.3 to 193.8 per million population between the financial years 1993-94 and 2004-05, a substantially greater increase than for older age groups, or for the population as a whole (36.2 to 80.3 per million population).

CONCLUSIONS

There is an urgent need for coordinated systematic studies of the epidemiology of food allergy in Australia, to ascertain risk factors and guide public health policy. An increased prevalence of food allergy has implications for public health and medical workforce planning and availability of allergy services in Australia.