Should some infants be screened before peanut introduction?
Best practices for introducing peanuts have changed dramatically over the past decade, with early introduction being recommended to reduce the likelihood of developing a peanut allergy. The screening of certain groups considered to be at high risk, such as those with moderate to severe eczema, has been the subject of debate. A investigation in the Journal of Allergy and Clinical Immunology examined the risk of peanut allergy before introducing peanuts in infants with another food allergy, a first-degree relative with a peanut allergy and moderate to severe eczema.1
Infants aged 4 to 11 months were recruited for the study using social media advertising, direct mail to various pediatric offices, letters to patients, and direct recruitment. In order to be included in the study, the infant could have no history of exposure or reaction to peanuts, no history of peanut immunoglobulin E or skin test, and have at least 1 risk factor: a other food allergy, a first degree relative with a peanut allergy and moderate to severe eczema. The infant underwent a physical examination, a skin test with peanut extract, histamine, saline solution and a blood test. Depending on the result of the prick skin test, the infant had either observed peanut feeding or oral challenge, or was referred to an allergy clinic with a diagnosis of peanut allergy.
There were 321 infants included in the study: 78 with eczema only, 11 with another food allergy only, 107 with a family history of the first degree only, and 125 with more than one risk factor. Investigators found that 18% of 195 participants with eczema, 19% of 59 infants with another food allergy, and 4% of 201 participants with a family history had a peanut allergy. Of the 115 with a family history but no eczema, only 1% had a peanut allergy. The investigators found that among infants with eczema, an older age (odds ratio [OR], 1.3; 95% CI, 1.04-1.68 per month), another suspected or diagnosed food allergy (OR, 3.98; 95% CI, 1.62-9.80), or Black (OR, 5.79 ; 95% CI, 1.92-17.4 compared to white) or Asian race (OR, 6.98; 95% CI, 1.92-25.44), or a higher atopic dermatitis SCORing score were linked to peanut allergy.
The researchers concluded that booking screening before introduction might be necessary only for infants with moderate to severe eczema. Additionally, as the later age of introduction is linked to a higher risk of peanut allergy in infants with eczema, the results continue to support the introduction of peanuts as early as possible in the life of a child.
1. Keet C, Pistiner M, Plesa M et al. Age and severity of eczema, but not family history, are major risk factors for peanut allergy in infants. Journal of Allergy and Clinical Immunology. 2021; 147 (3): 984-991.e5. doi: 10.1016 / j.jaci.2020.11.033