Early antibiotic exposure in neonates and infants, while critical for treating infections, may have unintended consequences.
This study, published in the European Journal of Paediatrics, sought to determine whether early antibiotic exposure increases the risk of childhood atopic dermatitis, asthma, or inhaled corticosteroid use.
The study reviewed the data from 11,255 children born in Southwest Finland between 2008 and 2010.
Children were grouped by neonatal antibiotic exposure as either a) no exposure, b) empirical antibiotic therapy (discontinued after infection was ruled out), or c) antibiotics for confirmed or clinically diagnosed infection.
Outcomes assessed included physician-diagnosed atopic dermatitis, asthma, or inhaled corticosteroid use by age 8-9 years.
Confounding factors such as older siblings, maternal BMI, smoking, pregnancy duration, delivery type, child's sex, and intrapartum antibiotics were controlled for.
1,255 children (11.2%) were exposed to antibiotics in the first 14 days of life:
- 592 (5.3%) received empirical antibiotics (median duration: 2 days)
- 663 (5.9%) received antibiotics for confirmed or clinically diagnosed infection (median duration: 7 days)
- 1,777 children (15.8%) received antibiotics after the neonatal period but before 6 months
The following findings were recorded:
Atopic Dermatitis
852 infants (7.6%) were diagnosed with atopic dermatitis during follow-up.
After adjusting for confounding factors, neonatal antibiotic exposure due to confirmed infection was associated with an increased risk of atopic dermatitis (OR 1.49).
Empirical antibiotic treatment showed no significant association.
Early antibiotic exposure before six months was also linked to a higher risk of atopic dermatitis (OR 1.38).
Asthma
849 infants (7.5%) were diagnosed with asthma.
No difference in neonatal antibiotic exposure was found between children who developed asthma and those who did not.
However, antibiotic exposure after the neonatal period but before six months was associated with a higher cumulative incidence of childhood asthma (OR 1.56).
Inhaled Corticosteroid Use
1,876 infants (16.7%) were prescribed inhaled corticosteroids.
Neonatal antibiotic exposure was not associated with inhaled corticosteroid use.
Antibiotic exposure before six months was more common in children who later required inhaled corticosteroids, with a significant association (OR 1.88).
CRP and Inflammatory Response
Plasma CRP concentrations were measured in 1,331 (11.8%) study subjects during the first week of life.
CRP levels were higher in neonates with confirmed infections compared to those not exposed to antibiotics or with empirical antibiotics ruled out.
However, maximum CRP concentrations were not associated with an increased risk of atopic dermatitis, asthma, or inhaled corticosteroid use later in childhood.
Composite Outcome: Asthma and Inhaled Corticosteroid Use
769 children (6.8%) were diagnosed with asthma and prescribed inhaled corticosteroids.
Exposure to antibiotics both in the neonatal period and before six months was more common in children who developed asthma and required inhaled corticosteroid therapy.
These findings indicate that neonatal antibiotic exposure for clinically diagnosed or confirmed infection is associated with increased occurrence of atopic dermatitis and antibiotic use after the neonatal period.
Additionally, use during the first six months of life is associated with an increased risk of atopic dermatitis, asthma, and inhaled corticosteroid use later in childhood. Further research is required to determine the causal mechanisms underlying the associations.