PURPOSE OF THE STUDY.
To evaluate associations of early-life antibiotic use with subsequent occurrences of a food allergy and other allergies in childhood.
Children born in Pennsylvania between 2001 and 2011.
The Geisinger Clinic electronic health record data on children born between 2001 and 2011, who had at least 2 outpatient encounters in the first 3 months of life, were assessed. Subjects’ data were collected up to 7 years of age. Diagnoses were classified as milk allergies, nonmilk food allergies, or other allergic conditions. Disease processes were determined by International Classification of Diseases, Ninth Revision codes. Incidence density sampling was used to identify 5 controls for every case individually, matched on sex and age. The Medi-Span Generic Product Identifier Therapeutic Classification System was used to identify the number and type of antibiotic orders before diagnosis of the allergy. Penicillins, cephalosporins, and macrolides were the antibiotic classes analyzed. Other variables studied included sex, race, use of public medical assistance, mode of delivery, outpatient encounters, and inpatient admissions.
Of the total population studied, 30 060 patients met eligibility criteria. Children with 3 or more antibiotic orders had greater odds of having a milk allergy (odds ratio: 1.78; 95% confidence interval: 1.28–2.48), a nonmilk food allergy (1.65; 1.27–2.14), and/or other allergies (3.07; 2.72–3.46) than children with no antibiotic orders. Children with any allergy were significantly more likely than controls to have public medical assistance, outpatient encounters, and antibiotic orders before an allergy diagnosis. Children with milk or nonmilk food allergies were also more likely to have inpatient encounters. Penicillin and cephalosporin orders had a stronger association with overall food allergy diagnoses than macrolides, when prescribed in the first 2 years of life.
The authors of this study found strong associations between antibiotic orders and diagnoses of milk allergies, nonmilk food allergies, and other allergic conditions in patients up to 7 years of age. Limitations of the study include the use of International Classification of Diseases, Ninth Revision codes to establish allergy issues. For food allergies, these codes can reflect an intolerance, adverse reaction, or sensitization, in addition to immunoglobulin E–mediated allergic reactions. For other allergy issues, a diagnosis of asthma or allergic rhinitis may not have been confirmed by spirometry or allergy testing. Compliance with antibiotic prescriptions could also not be studied. However, the strengths of this study include the large sample size and the use of physician diagnosis of allergic issues in relation to antibiotic orders. Consultation or protopathic (reverse-causality) bias alone cannot account for the associations between early-life antibiotic use and subsequent diagnoses of food allergies and other allergic issues.
Children with and without allergies have differences in their microbiota. Antibiotic use in early life has been linked to disruptions in the microbiome. The increase in the prevalence of allergies has paralleled the use of broad-spectrum antibiotics among children. This study adds to the literature supporting judicious use of antibiotics in early life.
- Copyright © 2017 by the American Academy of Pediatrics