The Impact of Family History of Allergy on Risk of Food Allergy: A Population-Based Study of Infants

Abstract

The apparent rapid increase in IgE-mediated food allergy and its implications are now widely recognized, but little is known about the relationship between family history (an indirect measure of genetic risk) and the risk of food allergy. In a population-based study of 5,276 one year old infants (HealthNuts), the prevalence of oral food challenge-confirmed food allergy was measured. Associations between family history of allergic disease and food allergy in infants were examined using multiple logistic regression. Food allergy was diagnosed in 534 infants. Compared to those with no family history of allergic disease, children meeting the current definition of “high risk” for allergic disease (one immediate family member with a history of any allergic disease) showed only a modest increase (OR 1.4, 95% CI 1.1–1.7) in food allergy, while having two or more allergic family members was more strongly predictive of food allergy in the child (OR 1.8, 95% CI 1.5–2.3). There were also differences in the associations between family history and egg and peanut allergy in the child. Re-defining “high risk” as two or more allergic family members may be more useful for identification of groups with a significantly increased risk of food allergy both clinically and within research studies.

Epidemiology of food allergy and food-induced anaphylaxis

“…Traditionally, 'high risk' was defined based on the presence of an immediate family member with allergy (asthma, eczema, allergic rhinitis or food allergy), but this is now extremely common in the general population (up to 70% of populationrecruited infants have a family member with allergy) and poses only a moderate increase in food allergy risk for the infant [34]. Intervention trials have more recently begun recruiting infants with eczema as a truly high risk group for food allergy development [35], although this can only be undertaken for trials of postnatal interventions.…”

Food Allergy

“…In a population-based study of one-year-old infants diagnosed via oral food challenge with food allergy (primarily egg or peanut), the risk of food allergy was increased by 40% in patients with one immediate family member with any allergic disease and by 80% in patients with two immediate family members with any allergic disease compared to children without a family history of allergy. 15 Race/ethnicity and other demographic characteristics are also associated with food allergy: non-Hispanic black ethnicity 4, 5, 16, 17 , Asian ethnicity 5 , and male sex in children 18,16 have all been associated with higher risk of food allergy. Overall, these findings suggest a genetic predisposition; however, the genetic determinants of food allergy are largely undefined.…”

Peanut allergy prevention: Current evidence and implications for clinical practice

“…Results revealed, 70% of participants had a positive family history and that having two or more allergic family members was strongly predictive of peanut allergy in the child, while having only one family member was not. 12 Both the results of the HealthNuts and LEAP studies challenge the clinical relevance of defining high risk as having only one family member with an allergic condition, as has been historically accepted.…”