P Bégin1,2, F Graham1, K Killer1, J Paradis1,2, L Paradis1,2, A Des Roches1. 1. Department of Pediatrics, Service of Allergy and Clinical Immunology, Centre Hospitalier Universitaire Sainte-Justine, Montreal, QC, Canada. 2. Department of Medicine, Service of Allergy and Clinical Immunology, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.
Abstract
BACKGROUND: The prevalence of peanut allergy in younger siblings of children with peanut allergy has been reported between 7% and 8.5%, but the anaphylactic risk at the time of introduction is currently unknown, which limits our ability to best counsel parents on this issue. OBJECTIVE: To determine the risk of anaphylaxis and working parameters of allergy testing in this context. METHODS: One hundred and fifty-four peanut-naïve younger siblings of peanut-allergic children underwent double-blinded skin testing, followed by parent-led peanut introduction. Questionnaires were dispensed to parents to investigate preferences with regard to peanut introduction in this subgroup. RESULTS: Eight participants (5.2%) presented unequivocal IgE-mediated reactions to peanut upon introduction, including five anaphylaxes. These participants were significantly older compared to the rest of the cohort (median 4.0 vs 1.9 years, P = 0.04). The negative predictive value of skin prick test with peanut extract and peanut butter and of specific IgE was 99%, 100%, and 100%, respectively. Six peanut-tolerant participants had positive peanut allergy tests. The option of introducing at home without prior skin testing was associated with high levels of anxiety (median 8.4 on 10-point Likert scale) when compared to supervised introduction (median 3.8, P < 0.0001) or home introduction after negative skin test (median 4.3, P < 0.0001). CONCLUSIONS: There is an increased risk of anaphylaxis upon peanut introduction in siblings of children with peanut allergy, and parents are reluctant to introduce at home without testing. Allergy testing prior to introduction is negative in over 90% of cases and carries a high negative predictive value.
BACKGROUND: The prevalence of peanutallergy in younger siblings of children with peanutallergy has been reported between 7% and 8.5%, but the anaphylactic risk at the time of introduction is currently unknown, which limits our ability to best counsel parents on this issue. OBJECTIVE: To determine the risk of anaphylaxis and working parameters of allergy testing in this context. METHODS: One hundred and fifty-four peanut-naïve younger siblings of peanut-allergic children underwent double-blinded skin testing, followed by parent-led peanut introduction. Questionnaires were dispensed to parents to investigate preferences with regard to peanut introduction in this subgroup. RESULTS: Eight participants (5.2%) presented unequivocal IgE-mediated reactions to peanut upon introduction, including five anaphylaxes. These participants were significantly older compared to the rest of the cohort (median 4.0 vs 1.9 years, P = 0.04). The negative predictive value of skin prick test with peanut extract and peanut butter and of specific IgE was 99%, 100%, and 100%, respectively. Six peanut-tolerant participants had positive peanutallergy tests. The option of introducing at home without prior skin testing was associated with high levels of anxiety (median 8.4 on 10-point Likert scale) when compared to supervised introduction (median 3.8, P < 0.0001) or home introduction after negative skin test (median 4.3, P < 0.0001). CONCLUSIONS: There is an increased risk of anaphylaxis upon peanut introduction in siblings of children with peanutallergy, and parents are reluctant to introduce at home without testing. Allergy testing prior to introduction is negative in over 90% of cases and carries a high negative predictive value.
Authors: Michael O'Sullivan; Sandra Vale; Richard Ks Loh; Jessica Metcalfe; Karin Orlemann; Sandra Salter; Ian Peters; Alan Leeb Journal: Med J Aust Date: 2020-01-25 Impact factor: 7.738