The largest ever study to investigate whether it is possible to prevent children with hay fever going on to develop asthma is under way at St Thomas' Hospital.
Researchers from King's College London, along with others from centres across the UK and Europe, are looking to recruit 600 children between the ages of 4 and 11 years who have no asthma symptoms but who have hay fever and need medication.
The idea is to study the youngsters to see if treatment with a prescribed and approved hay fever tablet, which contains natural grass pollen, can also reduce the risk of children with hay fever developing asthma.
For the first three years half the young recruits will be given the tablet every day and then followed for a further two years to determine if the treatment helps prevent them developing asthma. The other half will be given a placebo tablet.
Prof Gideon Lack and Dr Adam Fox are the principal investigators for King's College London.
"We know that childhood allergic hay fever increases the risk of asthma development in later life by up to seven-fold," says Dr Fox.
"This trial will determine if this hay fever treatment can prevent development of asthma in children with grass pollen allergy.
"We only have until the end of June for recruitment so we really need people to come forward to take part in the trial as soon as possible.
"Anyone interested should call 020 7188 6111 for more details."