Persistent Cow’s Milk Allergy Is Associated With Decreased Childhood Growth: A Longitudinal Study

To determine the long-term effects of persistent cow’s milk (CM) or peanut (PN) and/or tree nut allergy (TN) on growth past childhood age.

A retrospective chart review of 191 children with persistent IgE–mediated allergy to CM or PN and/or TN at age 9 seen at the John Hopkins Pediatric Allergy Clinic from November 1994 to March 2015. Patients adhered to a strict elimination diet and had clinic visits between the ages of 2–4, 5–8, and 9–12 years.

Clinical data and anthropometric measurements were collected at all visits for patients aged 2 to 12 years, or longer if available. Z scores were used to evaluate differences in weight, height, and BMI.

Children with persistent CM allergy had significantly decreased weight (0.39; 95% CI, 0.13 to 0.66) and height (mean z score difference, 0.39; 95% CI, 0.11 to 0.67) but not BMI for age when compared with children with PN/TN allergy. Mean z score differences for height were more pronounced as the children aged: 2–4 years, −0.12 (95% CI, −0.30 to 0.06); 5–8 years, −0.34 (95% CI, −0.54 to −0.14); 9–12 years, −0.43 (95% CI, −0.62 to −0.23); 13+ years, −0.63 (95% CI, −0.93 to −0.33). Mean z score differences for weight showed similar trends initially but beyond 13 years were not significant: 2–4 years −0.01 (95% CI, −0.19 to 0.16); 5–8 years −0.31 (95% CI, −0.51 to −0.11); 9–12 years −0.46 (95% CI, −0.67 to −0.24); 13+ years, −0.27 (95% CI, −0.61 to 0.07). Children with CM allergy also had significantly decreased weight and BMI z scores from baseline measurements (2 to 4 years of age) at older ages (weight: mean z score difference, 0.25; 95% CI, 0.06 to 0.43; P = .008; BMI: mean z score difference, 0.34; 95% CI, 0.09 to 0.59; P = .007). These findings were not affected by other atopic conditions or inhaled corticosteroid use. PN and TN allergy were not associated with significantly decreased weight, height or BMI-for-age. No stunting or wasting (z score <−2) was observed in children with milk allergy.

Patients with CM allergy had significant and progressively lower weight and height measurements throughout childhood that persisted into adolescence. Comparatively, PN and TN allergies were not associated with decreased weight, height, or BMI-for-age.

These findings indicate persistent CM allergy may negatively influence growth and development throughout childhood. Additionally, children with CM allergy often have other food allergies. Since the time of the study, the availability of dietary advice and nutritional alternatives has improved, so it is possible these findings may be less distinct currently. However, the findings highlight the importance of closely monitoring growth in children with CM allergy and providing guidance to ensure nutritional needs are met.