Factors influencing reintroduction of peanut and tree nuts after negative oral food challenges in children.

BACKGROUND: Compliance with reintroduction of foods after a negative oral food challenge (OFC) is variable. Ongoing avoidance of tolerated foods is associated with recurrence of allergy and a reduced quality of life. OBJECTIVE: To determine the proportion of children who reintroduced peanut or tree nuts after a negative OFC and to describe factors that influenced decisions regarding reintroduction or avoidance of nonallergic (negative) nuts. METHODS: Families of children that had undergone an OFC for peanut or tree nuts at Sydney Children's Hospital were invited to participate. Consenting families were sent an online questionnaire. RESULTS: The response rate to the questionnaire was 64%. More than 85% of respondents had introduced all or some of the negative nuts after the OFC and most had maintained at least some regular exposure in the child's diet at the time of the study. The age at diagnosis of the nut allergy and an awareness of the benefit of introducing foods after a negative OFC were significantly (P < .05) associated with introducing negative nuts. There was improved quality of life in those that introduced negative nuts. CONCLUSION: Most families introduced or attempted to introduce negative nuts after a negative OFC. Educating families on the benefits of introducing foods after a negative OFC result is an important factor contributing to successful reintroduction.

Skin testing with ultra-heat-treated (UHT) cow's milk in children with cow's milk allergy.

BACKGROUND: A large proportion of cow's milk (CM)-allergic children are able to tolerate extensively heated forms of CM such as baked goods. Little is known about whether ultra-heat-treated (UHT) forms of cow's milk are immunologically similar to extensively heated cow's milk and therefore may be tolerated by these children. OBJECTIVE: To determine whether skin test wheal size using UHT CM was significantly different from other forms of CM and CM extracts. METHODS: Children presenting for oral food challenges with either extensively heated or unheated cow's milk underwent skin prick test (SPT) to commercial CM, UHT CM, evaporated CM, and fresh whole CM. The results were compared between groups of children. RESULTS: At study exit, only 14% of children were avoiding all forms of CM, compared with 70% at study entry. No difference was seen in the mean SPT results for UHT CM between those children that could tolerate heated CM compared with those that could not. The mean SPT result for casein was significantly lower in those that could tolerate heated CM. However, within the group of heated milk-tolerant children, the mean SPT for UHT CM was significantly lower than the SPT for fresh whole CM. CONCLUSION: Ultra-heat-treated CM does not behave significantly differently from other forms of CM when evaluated by SPT in heated milk-allergic vs heated milk-tolerant children. This suggests that UHT CM is not sufficiently immunologically different from unheated CM to be tolerated by heated CM-tolerant children.

Bullying in Australian children and adolescents with food allergies.

BACKGROUND: Food allergy is an increasing concern worldwide. The significant impact of food allergies on quality of life and bullying has been well described in international studies. No studies have yet investigated the occurrence of bullying in children and adolescents with food allergies in the Australian population. This study aimed to characterize and examine the frequency of bullying and describe those most responsible and the effects of the bullying on the victims. METHODS: Questionnaires were developed based on those used in previous studies and were distributed throughout paediatric allergy clinics. Children and adolescents aged 10-19 with food allergies were recruited to complete the questionnaire independently, whilst parents completed the questionnaire on behalf of their children aged 5-9 with food allergies. The data were tabulated and analysed using descriptive statistics. RESULTS: Ninety-three questionnaires were completed. Overall, 39 (42%) children experienced some form of bullying. This was higher in the older children and adolescent group, where 53% (18/34) were bullied. In addition, 23% (21/93) of the cohort were bullied or teased specifically because of their allergy. Food allergens had been used in the bullying in 24 cases, but no child reported being forced to eat foods to which they were allergic. Two adolescents experienced allergic reactions. CONCLUSIONS: This study highlights that those with food allergy are subject to a high degree of bullying. This risk of bullying for children with food allergy indicates a significant social problem that requires addressing to positively assist these children.

Repeat oral food challenges in peanut and tree nut allergic children with a history of mild/moderate reactions.

BACKGROUND: In peanut and tree nut allergic children a history of anaphylaxis is associated with subsequent severe reactions. OBJECTIVE: We aimed to prospectively rechallenge peanut and tree nut allergic children with a history of mild/moderate reactions to assess their allergy over time. METHODS: In this cohort study peanut and tree nut allergic children with a history of mild/moderate reactions during a controlled oral challenge were invited to have a follow-up oral challenge to the same food at least 1 year later. RESULTS: Twenty-six children participated in the study. The mean time interval between the first and second challenge for all participants was 35.5 months. Peanut or tree nut allergy resolved in 38.5% of participants. Those with persistent peanut or tree nut allergy showed a decrease in their reaction threshold and/or increased severity in 81% of cases. There were no demographic features or skin test results that were predictive of changes in severity over time. CONCLUSION: Peanut and tree nut allergic children with a history of mild/moderate reactions who remained allergic demonstrated a high rate of more severe reactions and/or reduced thresholds upon rechallenge over a year later, however, the rate of resolution of allergy in this group may be higher than previously reported.

Parental satisfaction with oral peanut food challenges; perception of outcomes and impact on management of peanut allergy.

Oral peanut food challenges (OPFC) are the 'gold standard' for diagnosing peanut allergy in children. However, there are few data on parental perception of such challenges. We aimed to investigate the parental experience of and satisfaction with OPFC and reported dietary management of children with a history of peanut allergy following OPFC. Telephone interviews were conducted with parents of children who had undergone an open-label OPFC at a specialist paediatric allergy centre. Forty-six of 76 eligible parents participated. Of those parents, 54% were very satisfied with the OPFC. The highest levels of satisfaction were reported in relation to (i) clarification of the severity of the child's peanut allergy (ii) the support provided by staff and (iii) determining the child was tolerant of peanut or assessed to be at low risk of anaphylaxis from accidental peanut exposure. When the outcome of the challenge was perceived to be equivocal, levels of parental satisfaction were lower. Other areas of dissatisfaction included difficulties inducing peanut ingestion, parental distress at seeing their child unwell and perception of inadequate follow-up. Ninety-four per cent of parents could not remember the amount of peanut ingested, and 24% could not remember whether management advice was given after the OPFC or reported that none was given. Reported compliance with recalled advice to avoid peanut was found in all cases but one, whilst recalled advice to reintroduce peanuts following a negative challenge was followed in 5/9 cases. Although 12 parents reported that their child had an allergic reaction caused by accidental exposure to peanut since the OPFC, only four were certain peanut was the cause. Comprehensive education, counselling and follow-up subsequent to an OPFC are required. Parents of children whose challenge outcome is inconclusive should be targeted for support.

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.

Combining skin prick, immediate skin application and specific-IgE testing in the diagnosis of peanut allergy in children.

Previous studies have suggested various diagnostic cut-offs of allergy tests for the diagnosis of clinical peanut allergy in children. There are few data relating to the use of combinations of these tests in children. We aimed to determine the validity of previously reported diagnostic cut-off levels of peanut allergen skin tests and peanut specific-immunoglobulin (Ig) E, as well as the usefulness of combinations of these, for predicting clinical peanut allergy in our Allergy Clinic. Children attending the Allergy Clinic with a positive peanut skin prick test (SPT; n = 84) were included in the study. Immediate skin application food tests (I-SAFT) using 1 g of peanut butter (positive if any wheals were detected at 15 min), peanut specific-IgE levels and open-label peanut food challenges were performed. Fifty-two of 85 peanut challenges were positive. Skin prick test specificity was 67% at >or=8 mm and 100% at >or=15 mm. The I-SAFT was 82% specific. A peanut specific-IgE level of 0.37 kU/l was 98% sensitive but 33% specific. A level of 10 kU/l was 100% specific. Combinations of a SPT of >or=8 mm with a positive I-SAFT and a peanut specific-IgE >or=0.37 kU/l were 88% specific with a sensitivity of 38%. Using challenge outcomes as the standard, available in vitro and in vivo diagnostic tests for peanut allergy have poor sensitivity and specificity and combining them does not significantly improve their clinical usefulness. Previously described diagnostic cut-off levels do not have general applicability. Allergy practitioners may need to interpret results of allergy tests in the context of their own practices.