Mother's and offspring's use of antibiotics and infant allergy to cow's milk.
BACKGROUND
Evidence on the association between antibiotics and the risk of food allergies is limited. We explored the associations between mother's and offspring's use of antibiotics and the risk of cow's milk allergy in infancy.


METHODS
We used a national registry to identify all children who were born in 1996-2004 in Finland and diagnosed with cow's milk allergy after 1 month of age by November 2005 (n = 15,672). For each case, we selected one control matched for birth date, sex, and hospital district. Information on antibiotic purchases and putative confounders was obtained from registries. The associations were analyzed using conditional logistic regression.


RESULTS
Maternal use of antibiotics before and during pregnancy was associated with an increased risk of cow's milk allergy in the offspring (odds ratio = 1.26 [95% confidence interval = 1.20-1.33] and 1.21 [1.14-1.28], respectively, adjusting for putative confounders). The risk of cow's milk allergy increased with increasing number of child's antibiotics used from birth to diagnosis (test for trend P < 0.001).


CONCLUSIONS
Both maternal and child's use of antibiotics were associated with an increased risk of cow's milk allergy. Future studies are needed to confirm these novel findings and to explore the potential biologic mechanisms behind the association.
Department of Lifestyle and Participation, National Institute for Health and Welfare, Helsinki, Finland. johanna.metsala@thl.fi
Johanna
J
Metsälä
Annamari
A
Lundqvist
Lauri J
LJ
Virta
Minna
M
Kaila
Mika
M
Gissler
Suvi M
SM
Virtanen
D000328:Adult; D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D005387:Finland; D006801:Humans; D007223:Infant; D041943:Infant Formula; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D016269:Milk Hypersensitivity / Q000175:diagnosis / Q000209:etiology / Q000276:immunology*; D009035:Mothers; D011247:Pregnancy; D012042:Registries; D012306:Risk
D000900:Anti-Bacterial Agents