Childhood allergies such as asthma and eczema are gender related, research published in the Journal of Allergy and Clinical Immunology has confirmed.
The groundbreaking study found that maternal eczema doubled the risk of eczema in girls only, whereas paternal eczema did the same for boys. Similarly, maternal asthma is associated with increased risk of asthma only in girls, whereas paternal asthma is linked to asthma in boys.
Previous studies have revealed that allergies are hereditary, but believed that they were passed down from the mother.
Prof Hasan Arshad, a professor of Allergy and Clinical Immunology at the University of Southampton, who led the research, said, ‘If the father has an allergy, that increases the risk to twice or three times for the son, but not the daughter. She would still develop an allergy, but the risk is not increased; it’s the same as the general population.’
The findings have implications for child allergy prediction and prevention. Prof Arshad said they would ‘change our practices and give much better information to parents. Clinicians should now be asking not simply if parents have allergy, but specifically if the mother or the father has allergy.’
The study, which began in 1999, comprised skin prick tests on 1,456 children at the ages of one, two, four, ten and 18. It took into consideration parents’ allergy history soon after the birth of the child.
Leanne Metcalf, assistant director of research and practice at Asthma UK, said, ‘Scientists established a long time ago that asthma is caused by genetic and environmental factors. However, we don’t fully understand how all these factors, including gender, come together to cause asthma.
‘This study is exciting because it opens up interesting new avenues of research that could tell us more about the relative role of genes, environment and gender in terms of asthma risk, and enable us to use this information to potentially prevent asthma in the future.’
Bevis Man of the British Skin Foundation, said, ‘This news will hopefully spur a new wave of research looking into the differences between the sexes and the way in which a child is likely to develop eczema.
‘We know that for parents it can be a distressing time if their child develops eczema of any severity, so this knowledge can at the very least prepare them for what may occur as their children grow up.’
Margaret Cox, chief executive of the National Eczema Society, commented, ‘We already know that where one parent has eczema, asthma or hayfever, there is a one in four chance of a child getting eczema, and one in two chance where both parents have these conditions.
‘This research is very welcome as it builds on our existing knowledge about which children are at highest risk of developing eczema.’