Use of broad-spectrum antibiotics during infancy associated with increased risk of pediatric asthma

September 1, 2007

Children who receive broad-spectrum antibiotics during their first year of life are at increased risk of developing childhood asthma.That was the conclusion of researchers who conducted a large, longitudinal, case-control study.

Key Points

Children who receive broad-spectrum antibiotics during their first year of life are at increased risk of developing childhood asthma. That was the conclusion of researchers who conducted a large, longitudinal, case-control study published in the journal Chest.

A total of 13,116 children born in Manitoba, Canada who were continuously registered with the Manitoba Health Services Insurance Plan (MHSIP) until 2003 were included in this evaluation. In total, 65% of children received ≥1 prescription for antibiotics during the first year of life; 52% of these children received broad-spectrum antibiotics only; 3% of these children received narrow-spectrum antibiotics only; 10% of these children received both. The majority of children (55%) received ≥1 prescription for a broad-spectrum penicillin.

The children were followed through age 7. Asthma was defined as ≥2 physician visits for asthma, 1 hospitalization for asthma, or 2 prescriptions for any asthma drug in the year following the child's seventh birthday.

When study investigators evaluated different characteristics of antibiotics, they observed that the association between asthma and the use of broad-spectrum antibiotics was statistically significant (OR=1.50; 95% CI, 1.16–1.93). Use of narrow-spectrum antibiotics was not associated with a similar increased risk of asthma (OR=1.35; 95% CI, 0.29–6.23).

Patients who received ≥1 antibiotic prescription for nonrespiratory tract infections were nearly twice as likely to develop asthma by age 7 (OR=1.86; 95% CI, 1.02–3.37) compared with children who had not received antibiotics.

Among patients who received >4 courses of antibiotics in the first year of life, the risk of developing asthma was further increased if the patients lived in rural areas (OR=1.88; 95% CI, 1.23–2.88), if there was no history of maternal asthma (OR=1.57; 95% CI, 1.20–2.04), or if there was no exposure to dogs (OR=2.02; 95% CI, 1.20–3.38). The authors stated that a possible explanation for these results may be that a greater percentage of patients in these subpopulations received cephalosporins compared with the other patients.

The authors stated that given the results of their study, broad-spectrum antibiotics should be avoided during a child's first year of life if other antibiotics are available in order to reduce the risk of asthma development.

SOURCE

Kozyrskyj AL, Ernst P, Becker AB. Increased risk of childhood asthma from antibiotic use in early life. Chest. 2007;131:1753–1759.