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We read with interest the article by Kalaichandran et al about early allergenic solid introduction. We appreciate the focus on early introduction of allergenic solids, as it has been shown that both early peanut and early cooked egg introduction significantly reduce the risk of peanut and egg allergy respectively.1
Our main concern is with point #4 which recommends that infants with risk factors see a specialist for skin prick or sIgE testing prior to peanut introduction. We appreciate that in the LEAP study, pre-emptive screening prior to peanut ingestion was routine for all high-risk infants who participated.2 While this approach was a requirement of the research protocol, it is not yet established as a standard of care. In fact, the recent Canadian Pediatric Society practice point on food allergy prevention3 makes no mention of pre-emptive screening prior to peanut introduction. This recommendation is also not present in guidelines endorsed by the Australian4 or British5 national allergy societies.
The most important barriers to widespread adoption of pre-emptive allergen testing are the lack of feasibility outside of research, false positive results and the heavy burden related to over-testing and over-diagnosis. An Australian study estimated that pre-emptive screening of all infants potentially considered “high risk” for peanut allergy would result in screening 16% of the infant population requiring testing while still missing 23% of peanut allergy cases.6 A Canadian survey that we performed noted that the majority of allergists, pediatricians and family physicians do not recommend pre-emptive testing prior to peanut introduction and that the majority of allergists are not comfortable following up on moderately positive allergy testing.7,8 Concerns have also been raised that pre-emptive testing may result in a ‘screening creep’ and inadvertently result in delaying peanut introduction.9 Significant systemic barriers exist for carrying out oral food challenges, as we recently described in the first Canadian study of oral food challenge implementation.10 Infants with no history of peanut ingestion but positive skin prick tests (i.e. high potential for false positives) who are never offered oral food challenges will be placed at ironically increased risk of developing peanut allergy due to prolonged peanut avoidance. Other infants with positive skin prick tests placed on long waitlists for infant oral food challenges could completely bypass the window of opportunity for primary prevention, again increasing risk.
While specific amounts of peanut ingestion were recommended by Kalaichandran et al, to date there is inconclusive data regarding the exact amount and periodicity of peanut protein ingestion required to prevent peanut allergy. While the LEAP study used a protocol of 6 grams of peanut protein per week distributed in three or more meals,2 this has never been replicated and to date no study has tested whether a smaller amount would give the same protection. Current Canadian guidance recommends feeding peanut a few times a week once introduced, if well tolerated, but does not specify exact amount or frequency as that remains unknown.3
We believe the recent Canadian Pediatric Society practice point on food introduction strikes a more appropriate balance of what is known and what is feasible in a Canadian context, and discourage any messages that promote blanket pre-emptive screening for any risk category. The key simple message for health care providers and parents is to introduce peanut and other common allergens between around 6 but not before 4 months of age at home (especially if a child is atopic or has a family history of allergies) and keep these foods in the diet on a regular basis if well tolerated.3
References
1. Ierodiakonou D, Garcia-Larsen V, Logan A, Groome A, Cunha S, Chivinge J, et al. Timing of Allergenic Food Introduction to the Infant Diet and Risk of Allergic or Autoimmune Disease: A Systematic Review and Meta-analysis. JAMA. 2016;316:1181–92.
2. Du Toit G, Roberts G, Sayre PH, Bahnson HT, Radulovic S, Santos AF, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. 2015;372:803–13.
3. Abrams EM, Hildebrand KJ, Blair B, Chan ES. Timing of introduction of allergenic solids for infants at high risk. Paediatr Child Heal. 2019;24:66–7.
4. Netting MJ, Campbell DE, Koplin JJ, Beck KM, McWilliam V, Dharmage SC, et al. An Australian Consensus on Infant Feeding Guidelines to Prevent Food Allergy: Outcomes From the Australian Infant Feeding Summit. J Allergy Clin Immunol Pr. 2017;5:1617–24.
5. BSACI: Preventing food allergy in higher risk infants: guidance for healthcare professionals [Internet]. [cited 2019 Mar 24]. Available from: https://www.bsaci.org/pdf/Early-feeding-guidance-for-HCPs.pdf
6. Koplin JJ, Peters RL, Dharmage SC, Gurrin L, Tang MLK, Ponsonby A-L, et al. Understanding the feasibility and implications of implementing early peanut introduction for prevention of peanut allergy. J Allergy Clin Immunol\. 2016;138:1131-1141.e2.
7. Abrams EM, Singer AG, Soller L, Chan ES. Knowledge Gaps and Barriers to Early Peanut Introduction Among Allergists, Pediatricians, and Family Physicians. J Allergy Clin Immunol Pr. 2019;7:681–4.
8. Abrams EM, Soller L, Singer AG, Fleischer DM, Greenhawt M, Chan ES. Comparison of practice patterns among Canadian allergists before and after NIAID guideline recommendations. J Allergy Clin Immunol Pr. 2019;
9. Turner PJ, Campbell DE. Implementing Primary Prevention for Peanut Allergy at a Population Level. JAMA. 2017;317:1111–2.
10. Hsu E, Soller L, Abrams EM, Protudjer JLP, Mill C, Chan ES. Oral food challenge implementation: the first mixed-methods study exploring barriers and solutions. J allergy Clin Immunol Pract. 2019;