In a pioneering study, researchers at the NIHR Southampton Respiratory Biomedical Research Unit recruited 111 children with a history of allergy in both parents and gave half oral drops of dust mite allergen and half a placebo.
They administered the treatments twice a day from the age of six months to 18 months and discovered exposure to the common allergen, which is often found in pillows, mattresses and on carpets, in this way reduced the incidence of allergy by almost two-thirds (63%).
"These findings are extremely exciting as we have shown that a simple and safe treatment - oral dust mite extract - given to children at high risk reduces the early development of allergy," said Professor Hasan Arshad, a consultant in allergy based at Southampton General Hospital.
"Although, dust mites are an important cause of asthma and allergy, using the same allergen in an oral extract form, known as immunotherapy, can reduce the body's reaction to not only dust mites, but also other important allergens.
"As a result, we think there is a strong possibility this could now lead to the prevention of asthma, eczema and other allergic diseases."
As many as one in four people in the UK are affected by an allergic disease and, as allergies start early in life, children bear the brunt of the diseases.
In the UK, dust mites are the most prevalent allergy-triggering substance, inducing reactions in a high proportion of children with asthma.
Prof Arshad, chair of allergy and clinical immunology at the University of Southampton, said previous studies carried out by his team showed around a quarter of all high risk children have evidence of an allergy at 18 months and they are at high risk of developing asthma later in life.
The findings, presented today (Wednesday) at the European Academy of Allergy and Clinical Immunology Congress in Copenhagen, showed results in the placebo group were as expected - 25.5% developed allergy to dust mites or other allergens - but the dust mite extract intervention group saw that happen in only 9.4%.
Professor Graham Roberts, a consultant in paediatric allergy and respiratory medicine, added: "Reduction in allergies at an early age should lead to a reduction in the development of asthma later in childhood.
"We still need to show that asthma can be prevented but, having reduced reactivity to this allergen, there is a high likelihood we won't see asthma develop in these children."
Prof Arshad, who is also director of the David Hide Asthma and Allergy Research Centre on the Isle of Wight, said the team would now follow the children up at three and five years of age and consider plans for a large multi-centre study in the near future.