Boys from wealthy families are more likely to be diagnosed with peanut allergy, a government-funded study has claimed.
Scientists also said boys generally are around 33% more likely to have this kind of allergy than girls but admitted that they could not fully explain their findings and needed to carry out more research.
The study looked at the health records of around 400 GP practices in England from between 2001 and 2005. Appearing in the Journal of Allergy and Clinical Immunology, the findings suggested that males under 20 are almost a third more vulnerable to peanut allergies than females of the same age group.
However, this trend goes into reverse in adulthood with slightly more women than men at risk. According to the researchers, this can be explained by the fact that after the age of 15, females are more likely to visit their GP and, therefore, have the allergic condition detected. And biological changes during puberty might create more immune system-driven allergic reactions.
The highest rates of peanut allergy were found in children aged five to nine.
The research suggests around 25,000 people in England have had a peanut allergy at some point, fewer than past estimates, although this new figure may arise from GPs under-recording cases.
Daniel Kotz, who led the Department of Health-funded study, said: "This research has shown that whilst peanut allergy is less common than previously thought, it affects over 25,000 people in England. Having a serious allergy like this can cause great anxiety and stress to those affected.
"We now need more research to help explain why the condition occurs relatively more often in boys and affluent people."