Good news for parents. Just because one of your children has a food allergy does not automatically mean your other children will also be allergic.

US researchers looked at 1,120 children, all of whom had a sibling with a documented food allergy. They found that 53% of the children had a food sensitivity, but just 13% had an actual food allergy.

"Too often, it's assumed that if one child in a family has a food allergy, the other kids need to be tested for food allergies. But testing for food allergies if a reaction hasn't taken place can provide false-positives, as we saw in our research.

"More than half the kids in the study had a sensitivity to a food, but they weren't truly allergic. Kids who have a food sensitivity shouldn't be labeled as having a food allergy," commented the study's lead author, Dr Ruchi Gupta, a member of the American College of Allergy, Asthma and Immunology (ACAAI).

An allergic response to a food can lead to stomach cramps, vomiting, wheezing, shortness of breath, tightness in the throat, hives, dizziness and feeling faint.

The researchers noted that the risk of a child having a food allergy simply because their sibling has one ‘has never been completely clear'.

"This perceived risk is a common reason to seek 'screening' before introducing a high-risk allergen to siblings. But screening a child before introducing a high-risk allergen isn't recommended. Food allergy tests perform poorly in terms of being able to predict future risk in someone who has never eaten the food before.

"Our study showed that testing should be limited in order to help confirm a diagnosis, rather than as a sole predictor to make a diagnosis," they said.

Details of these findings were presented at the ACAAI Annual Scientific Meeting in Texas.