For the new study, researchers recruited pregnant women at one Swedish hospital and followed them and their children for three years.
The 184 infants in the study were particularly allergy-prone because 80 per cent had at least one parent with allergies.
When the babies were six-months-old, 65 parents reported 'cleaning' their dummies by sucking on them.
The children were tested for allergies at 18-months-old and 46 of them had eczema and ten had asthma symptoms.
The transfer of bacteria in the mouth from parents to babies may help strengthen a child's digestive system which could in turn boost immunity
Those whose dummies had been sucked on by their parents were 63 per cent less likely to have eczema and 88 per cent less likely to have asthma, compared to the children of parents who did not use the cleaning technique.
By 36-months-old, however, the difference had disappeared for asthma.
Parental dummy sucking was still tied to a 49 per cent lower chance of a child having eczema, the researchers from Queen Silvia Childrenโs Hospital in Gothenburg found.
This is a simple measure which is really, really nice,' Dr Karmaus said. 'But we need a trial to be really sure that this is protective.'
Read more: http://www.dailymail.co.uk/health/article-2320187/Sucking-babys-dummy-giving-prevents-asthma-eczema-...
