Children are as likely to inherit eczema from their fathers as they are from their mothers, research suggests.
The number of people with eczema is increasing
Their conclusions are based on results from an ongoing study called Children of the 90s based at Bristol University.
It had been thought by some that eczema was more likely to have come from the mother's side of the family.
The research involving about 8,000 children also suggests parental eczema is a better marker than parental asthma or hay fever of childhood eczema.
The parents were asked to fill out questionnaires about any family history of allergic or atopic diseases such as asthma, hay fever and eczema.
The study authors then compared this information with the children's records of eczema up to the age of three-and-a-half.
In families where neither parent had eczema, 28% of the children showed signs of eczema.
When either the mother or the father had eczema this rose to 40% and if both parents had eczema 52% of the children had eczema.
There was no evidence that associations with maternal atopy were stronger than with paternal.
A history of eczema also seemed to be more important than a history of general allergy.
Lead author Dr Nellie Wadonda-Kabondo said: "While doctors have tended to group the atopic diseases together, our findings support the idea that there are several different genes involved.
"The child's risk of developing eczema was much higher if parents had a history of eczema, but if parents had hay fever or asthma the risk of the child developing eczema was substantial only if both parents had one or both of these diseases.
"It is important to establish the patterns of how children inherit eczema so that we can search for the genes that cause this disease."
On the increase
Margaret Cox, chief executive of the National Eczema Society, said: "It's interesting and we welcome anything that increases our understanding of eczema.
"It's part of a continuing jigsaw.
"We still, remarkably and worryingly, know little about this disease, despite the fact that it is becoming an increasing common disease.
"Hopefully this could help put us in a better position to be able to cure or even prevent the disease in the future."
She said tackling eczema early on in life might, in turn, prevent the onset of other allergic disease such as asthma and hay fever.
Dr Tom Poyner, vice chairman of the Primary Care Dermatology Society, said it was also important to consider which environmental factors might be contributing to eczema.
The study findings have been published in Archives of Disease in Childhood.