Study confirms eczema-asthma links
A new study confirming the temporal links between childhood eczema and rhinitis and adult-onset atopic asthma is highlighting the need to rigorously treat childhood allergies.
Associate Professor Shyamali Dharmage says this is one of the key implications of new research from MEGA Epidemiology, within the Melbourne School of Population Health. This paper focused on childhood eczema and rhinitis as predictors of atopic (or allergy-triggered) and non-atopic adult asthma.
It draws on the valuable resource of the Tasmanian Longitudinal Health Study (TAHS), which started in 1968 and profiled the asthma risk of almost all Tasmanian children born in 1961. Associate Professor Dharmage is the lead investigator of TAHS, which continues to generate important insights into the complex causal links between childhood allergies and asthma.
The lead author of this paper is Pamela Martin, a PhD student based at the Murdoch Childrens Research Institute (MCRI) and jointly supervised between MCRI and MEGA Epidemiology. This paper is soon to be published in the influential Journal of Allergy and Clinical Immunology, the highest-ranking allergy journal. It advances international knowledge in this field with a series of notable ‘firsts’. It is the first study to show a strong link between eczema and rhinitis measured in childhood, and atopic (allergy-triggered) current asthma at age 44. It is also the first to examine at the population level the relative contributions of combined eczema and rhinitis, with respect to persistent childhood asthma and new-onset asthma later in life. Importantly, it is the first to distinguish between atopic and non-atopic asthma and their occurrence after childhood eczema and rhinitis, as part of the sequence dubbed the ‘atopic march’.
Among the new study’s very significant results was that having both eczema and rhinitis in childhood (before age seven) led to a nine-fold increased risk of current atopic adult asthma. The researchers estimate that up to 30% of current atopic asthma within the larger population sample could be attributed to a history of childhood eczema and rhinitis.
The implications of this study are that prevention and rigorous treatment of childhood eczema and rhinitis may prevent adult asthma. Associate Professor Dharmage is concerned that the public is too casual in their attitude to treating eczema and hay fever, unaware of the potentially debilitating – or even fatal – health implications that lie ahead in adulthood. “While adult asthma itself is a serious health issue it should also be noted that asthma itself is an established risk factor for emphysema and chronic bronchitis,” she says. “These chronic respiratory diseases lead to obstruction of lung function affecting quality of life and productivity as you age.” To prevent this sequence of events interventions that can halt the march from childhood allergies to asthma need to be identified.
A MEGA research team has completed a pilot study in 2010 to trial strategies for halting the atopic march. This was led by Research Fellow Dr Adrian Lowe and he will lead a larger trial in 2011. The aim of this work is to establish whether a ceramide-based cream can prevent babies developing eczema and improve their skin barrier function in early life, and thereby prevent subsequent development of asthma.
If successful strategies to arrest the atopic march are identified this could ultimately save lives and health care costs related to asthma management and treatment. In 2000, 454 deaths were attributed to asthma and the total health system cost of asthma was estimated to be $438 million.
Caption: Associate Professor Shyamali Dharmage