PURPOSE OF THE STUDY:
To evaluate the prevalence, symptoms, and severity of egg allergy, with a specific focus on those with baked-egg tolerance and other associations via a large, population-based study of US households.
Children aged 0 to 17 years with an egg allergy identified by a national survey.
The authors used a US population-based cross-sectional survey administered to a sample of 53 575 US households from October 2015 to September 2016. The primary outcomes were as follows: prevalence of current and outgrown egg allergy by using stringent criteria, psychosocial burden, and quality of life.
The overall prevalence of egg allergy was 0.9% of all children and 1.3% of children <5 years of age. Prevalence appeared to be greater in Black children and in younger children (<5 years of age), compared with the other top 8 food allergies. The peak prevalence was between 1 and 2 years of age (2%), with a gradual decline across childhood, dropping to 0.5% in 14- to 17-year-olds. Egg-allergic children were more likely to have atopic comorbid conditions, including eczema (19%), asthma (46.5%), environmental allergies (38.2%), and eosinophilic esophagitis (1.2%). Asthma was more prevalent in egg-allergic children, compared with children with the other top 8 food allergies. Baked-egg tolerance was reported among 64.2% of egg-allergic children. Baked-egg intolerant children were more likely to be allergic to other foods, especially milk. Among egg-allergic children, 60.2% had additional food allergies, with milk (35.2%) and peanut (29.3%) being the most common. Overall, 28.1% reported experiencing a severe allergic reaction and were more likely to have had emergency department visits in their lifetime for any food-allergic reaction, compared with children with other food allergies and those who were baked-egg tolerant. A physician diagnosis did not occur in 27.8% of children with convincing egg allergy, with no difference related to baked-egg tolerance. A total of 34% of egg-allergic children with severe reactions and 25% of those without severe reactions lacked a physician diagnosis. There were no differences on the basis of sex, age, race, or ethnicity. Having an epinephrine autoinjector (EAI) and use of an EAI were less frequent in children without a physician diagnosis, but only 58.4% overall had an EAI prescribed. A total of 27% of children in the survey reported outgrowing egg allergy, which was often preceded by becoming baked-egg tolerant. Baked-egg tolerance was associated with a better quality of life.
Egg allergy is common among young children, with a peak prevalence of 2% in children 1 to 2 years of age. Children with egg allergy have a higher prevalence of other atopic conditions, particularly asthma. Increased efforts are needed to ensure that children with an egg allergy are appropriately evaluated to assess for comorbid food allergy, other atopic conditions, and baked-egg tolerance.
Egg allergy is often undiagnosed, and EAIs are underprescribed for this population. Asthma occurs in a surprising number of these patients, and providers need to have a high index of suspicion of this as children get older.