Key Clinical Summary

• A systematic review and meta-analysis of 190 studies involving 2.8 million children across 40 countries estimated incidence food challenge–confirmed food allergy at 4.7%.

• Early atopic dermatitis showed a strong association with food allergy (OR, 3.88; RD, 12.0%), as did increased transepidermal water loss (OR, 3.36; RD, 10.0%).

• Delayed peanut introduction, antibiotic exposure, family history, and several demographic and birth-related variables were also associated with increased risk.

A multinational systematic review and meta-analysis published in JAMA Pediatrics identified early allergic conditions, impaired skin barrier function, delayed allergen introduction, genetics, antibiotic exposure, and demographic factors as credible predictors of food allergy before age 6 years. The analysis included 190 studies and approximately 2.8 million participants from 40 countries.

Study Findings

Investigators searched MEDLINE and Embase through January 1, 2025. Incidence estimates were limited to studies confirming food allergy through food challenge, while risk-factor analyses included cohort, case-control, and cross-sectional studies using multivariable methods.

Across food challenge–based studies, the estimated incidence of childhood food allergy was 4.7%, supported by moderate-certainty evidence. Among 176 studies, investigators evaluated 342 potential risk factors with varying levels of certainty.

Early allergic disease produced some of the largest associations. Atopic dermatitis during the first year of life was associated with an OR of 3.88 and an RD of 12.0% (95% CI, 8.8%-15.7%). Allergic rhinitis was associated with an OR of 3.39 and an RD of 10.1%, while wheeze had an OR of 2.11 and an RD of 5.0%.

Markers of impaired skin barrier function were also associated with food allergy. Increased transepidermal water loss had an OR of 3.36 and an RD of 10.0%; filaggrin gene sequence variations had an OR of 1.93 and an RD of 4.2%.

Introducing peanut after age 12 months was associated with increased risk (OR, 2.55; RD, 6.8%). Antibiotic exposure during the first month of life had an OR of 4.11, although its RD estimate had a wide 95% CI of 0.4% to 40%.

Clinical Implications

The findings identify multiple characteristics associated with childhood food allergy, but the observational evidence does not establish causation. For clinicians, early atopic dermatitis, allergic rhinitis, wheeze, skin barrier dysfunction, and family history may help characterize children with increased likelihood of developing food allergy.

Additional associations included male sex, firstborn status, parental migration, cesarean delivery, and self-identification as Black compared with White or non-Hispanic White populations. The study did not identify significant risk differences for low birth weight, postterm birth, maternal diet, or maternal stress during pregnancy.

Because certainty varied among the 342 evaluated factors, individual associations should be interpreted alongside their effect estimates and confidence intervals.

Expert Commentary

Lead author Nazmul Islam and colleagues, affiliated with the Evidence in Allergy Group and McMaster University in Hamilton, Ontario, described the most credible predictors as “a combination of major and minor risk factors.” These included early allergic conditions, delayed allergen introduction, genetic susceptibility, antibiotic exposure, demographic characteristics, and birth-related variables. Professional titles were not provided in the source.

The multinational findings offer a consolidated estimate of food allergy incidence and associated early-life factors. Further research is needed to clarify which potentially modifiable exposures contribute directly to food allergy and which primarily identify children already at elevated risk.

Reference: Islam N, Chu AWL, Sheriff F, et al. Risk factors for the development of food allergy in infants and children: a systematic review and meta-analysis. JAMA Pediatr. 2025;180(5):486-499. doi:10.1001/jamapediatrics.2025.6105