Age 1 food allergies often disappear by age 6

SAN FRANCISCO – A peanut or egg allergy diagnosed when infants were 1 year of age often resolved by the time they turned 6, in a longitudinal, population-based study of more than 5,000 Australian children.

^{Mitchel L. Zoler/MDedge News}

Dr. Rachel L. Peters

Among 131 infants diagnosed with a peanut allergy when they were 1 year old and then followed with repeat testing 5 years later, 41 (31%) had complete resolution of their peanut allergy, while the allergy persisted in the other 90 children, Rachel L. Peters, PhD, said at the annual meeting of the American Academy of Allergy, Asthma, and Immunology. The study also followed 404 infants diagnosed with an egg allergy at 1 year of age and found that by age 6 the allergy had resolved in 368 (91%), while persisting in 36 children, said Dr. Peters, an epidemiologist at Murdoch Children’s Research Institute in Parkville, Australia.

The analysis also identified risk factors that linked with an increased rate of allergy persistence. For peanut allergy persistence beyond the first year, the correlating factors were early-onset eczema, tree nut allergy, and a stronger peanut allergy identified by a greater than 4-mm reaction to a peanut skin-prick test. Factors that linked with an increased rate of persistent egg allergy were eczema, peanut allergy, gastrointestinal or respiratory reaction symptoms to milk, and reaction on an oral food challenge elicited by a low dose (less than 0.5 mL) of milk.

A consequence of the frequent resolution of these food allergies was that a positive skin-prick test reaction to either peanut or egg at 1 year old was poorly predictive of allergy status at age 6, while skin-prick tests at age 6 worked well for identifying a persistent food allergy at that age.

The analyses that Dr. Peters and her associates ran used data collected in the HealthNuts study, a comprehensive, prospective, population-based study of food allergies in children that enrolled 5,276 infants at 1 year old. The HealthNuts researchers enrolled infants at immunization clinics in the Melbourne area, with enrollment stratified to represent the people who live in that region (Clin Exp Allergy. 2010 Oct;40[10]:1516-22).

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SOURCE: Peters R et al. J Allergy Clin Immunol. 2019 Feb;143[2]:AB421.