Researchers in Sweden identified 2151 children with celiac disease from a national register of child health, covering the period from 1973 to 1997.
The research team classified month of birth into winter season, including autumn and summer season, including spring.
They found that the risk of celiac disease was significantly higher for children born in the summer, compared with the winter.
However, this was only true for children below 2 years of age at diagnosis.
|Risk of celiac disease significantly higher for children born in the summer.|
|Journal of Epidemiology and Community Health|
This seasonal pattern prevailed during a 10-year epidemic of celiac disease, when levels of the disease varied threefold.
They also found that incidence was higher among girls, compared to boys. However, boys showed a more pronounced seasonal variation in risk.
The team suggests that this may be due to causal environmental exposure that changes during the year.
Dr Ivarsson's team concluded, "Infections might be the exposure of importance, either by means of a direct causal role and/or through interaction with other exposures, for example, gluten intake".
"However, non-infectious exposures should also be explored as possible contributing causal factors".