(HealthDay)—The risk of anaphylaxis is increased upon peanut introduction in siblings of children with peanut allergy, according to a study published online June 13 in Allergy.

Philippe Bégin, M.D., Ph.D., from Centre Hospitalier Universitaire Sainte-Justine in Montreal, and colleagues conducted double-blinded skin testing in 154 -naive younger siblings of peanut allergic children, followed by parent-led peanut introduction. Parents completed questionnaires to examine preferences with respect to peanut introduction.

The researchers found that there were unequivocal immunoglobulin E (IgE)-mediated reactions to peanut upon introduction in 5.2 percent of participants, including five anaphylaxes. Compared with the rest of the cohort, these participants were significantly older (median, 4.0 versus 1.9 years; P = 0.04). The negative predictive value of skin prick test was 99, 100, and 100 percent with peanut extract, , and specific IgE, respectively. Positive peanut allergy tests were seen for six peanut tolerant participants. Compared with supervised introduction or home introduction after negative skin test, the option of introducing at home without prior test was associated with high levels of anxiety (median 8.4 versus 3.8 and 4.3 on 10-point Likert scale, respectively; both P < 0.0001).

"There is an increased risk of anaphylaxis upon peanut introduction in siblings of children with and parents are reluctant to introduce at home without testing," the authors write.