The prevalence rates of food allergy and atopic dermatitis in low birthweight infants were evaluated. In Fukuoka City, Japan, between July 1994 and September 1997, sufficient information including birthweight, gestational age, sex, feeding method and a history of food allergy was obtained from questionnaires at the well-baby check-ups of 21766 infants (18 mo of age) and 4378 children (3 y of age). All the children were examined by pediatricians with regard to the existence of atopic dermatitis. The prevalence rate (8.1%) of food allergy in infants with low birthweight (<2,500 g) was significantly lower than that (11.2%) in infants with normal birthweight (> or = 2,500 g) at 18 mo of age (p = 0.0002). Atopic dermatitis was also observed at a lower prevalence rate (1.2%) in infants with low birthweight than in those with normal birthweight (2.3%) at the same age (p = 0.0041). However, this significance was lost at 3 y of age. Other characteristics including male sex and breast-feeding showed independent risks for the development of food allergy and atopic dermatitis at both ages.
Conclusion: This study found that low birthweight was significantly associated with a lower risk of both food allergy and atopic dermatitis at 18 mo of age.