The research team at The David Hide Asthma and Allergy Research Centre, St Mary’s Hospital is delighted at the acceptance by two prestigious medical journals, ‘Thorax’ and ‘Paediatrics’, of findings from the 10-year follow-up of the Isle of Wight Birth Cohort. This will make eight major publications arising from the latest study visit.
1456 children born on the Island between 1st January 1989 and 28th February 1990 have participated in this study following the natural history of asthma and allergic disease. The children had previously been followed-up at the ages of 1, 2 and 4 years.
Ninety-four percent of the original study group completed the 10 year update of the study. This is a substantially higher follow-up rate than other internationally recognised studies in this field in USA, Australia, New Zealand and Germany.The findings at age 10 years include;
- 1 in 3 children had a currently diagnosed allergic disorder (asthma, rhinitis, eczema, food allergy or urticaria).
- 1 in 5 children had current wheezing whilst 1 in 8 had current asthma. Both were commoner in boys and often associated with presence of other allergic states. Contrary to the view that childhood asthma is usually allergic we actually found that there is a large quantity of non-allergic wheezing at 10-years. This appeared to be less easily recognised and possibly under treated in comparison to the more well known allergic wheezing state. These findings suggest that allergy is an associated feature, but not a direct cause of childhood asthma. Inheritance appeared the main factor leading to the development of wheezing and asthma with some interaction from early life environment.
- 1 in 7 children had current eczema. Eczema has been commonly viewed as a transient disorder of infancy, but we identified a substantial burden of eczema that persisted throughout childhood.
- 1 in 5 children had current rhinitis. This was mostly in the form of summer hay fever and of recent onset. It was usually associated with allergies to inhaled allergens like house dust mite, grass pollen or cat. Rhinitis and wheezing often co-existed supporting a notion of “one airway-one disease” for these two states.
- Throughout the first decade of life 40% of children had wheezing illnesses. Of these most occurred in early life. There is a common belief that such early life wheezing is a transient problem that the child readily outgrows. However we found that 37% of such early life wheezers had a persistent problem still present at age 10. These children were most likely to have troublesome asthma, need high levels of treatment and have severe exacerbations needing hospital admission. By 10-years such children were beginning to show significantly weaker lung function than their healthier counterparts.
- We developed a simple 4 item risk score to identify persistent wheezers at an early age and differentiate them from children with less significant transient wheeze. This was published in the European Respiratory Journal in November 2003. Children with persistent wheeze were twice as likely to have a family history of asthma, twice as likely to have recurrent chest infections in infancy, half as likely to have recurrent nasal symptoms in infancy and six times as likely to be allergic on allergy testing in early childhood. If all 4 points on the score were positive a child would have an 83% chance of being a persistent wheezer – if all were negative they would have an 80% chance of transient disease.
- An interaction between inheritance and early life environment was found to be associated with the development of childhood wheeze and asthma over the first decade. Amongst children with a persistent asthma state, early life environment as dictated by parental smoking, infantile chest infections and low social class was found to have led to earlier onset of disease. This suggests that early life is a crucial period that may influence later health outcomes.
Considerable interest has been generated in the study findings with over twenty presentations being given to international conferences. Funding is currently being sought for a further follow-up in 2005/6 as the children reach 16 years of age. The research team is keen to hear from any of the children who have moved home since the last follow-up when many were living on the mainland and as far afield as Australia, New Zealand, Greece, Netherlands, France and Canada.