Asthma, rhinitis, and eczema classified together as an allergic comorbidity cluster

Asthma, rhinitis, and eczema often co-occur in children but they are considered and treated as different independent diseases. In a study published in Allergy, researchers from CREAL, an ISGlobal allied center, assessed co-occurrence of childhood asthma, rhinitis, and eczema.

In this study, led by Judith Garcia-Aymerich, CREAL researcher, more than 17,000 children at 4 years and more than 14,500 at 8 years were included from seven European-population-based birth cohorts, as part of the MeDALL Project, coordinated by Josep Maria Antó, researcher and director of CREAL.

At each age period, children were grouped according to the distribution of 23 variables covering symptoms "ever" and "in the last 12 months", doctor diagnosis, age of onset, treatments of asthma, rhinitis, and eczema, weight, and height.

A statistical model called cluster analysis, was used to see how many diseases could be identified in this population. The model distinguished two different groups both at the ages of 4 and 8 years. One group include the large majority of children with symptoms of asthma, rhinitis and/or eczema, suggesting that these diseases can be classified together as part of the same disorder. The other group included the vast majority of children without symptoms and most of those which symptoms did not qualify for a diagnosis of asthma, rhinitis and/or eczema. 99% children with comorbidities (co-occurrence of asthma, rhinitis, and/or eczema) were included in the symptomatic group.  The cluster model was repeated under many different circumstances, a strategy called sensitivity analysis, to examine the robustness of the results which were widely conformed.

Researchers conclude that at 4 and 8 years, at the population level, asthma, rhinitis, and eczema can be classified together as an allergic comorbidity cluster. These results have implications not only for research but also for the medical practice in relation to allergic diseases. “Future research including time-repeated assessments and biological data will help understanding the interrelationships between these diseases”, concludes Antó.

MeDALL in Barcelona

These results were commented last May 11th-12th in Barcelona, at the final meeting of MeDALL, an international four-year EU research project on the causes explaining the epidemic of allergic diseases.

Reference

Garcia-Aymerich J et. al. Phenotyping asthma, rhinitis, and eczema in MeDALL population-based birth cohorts: an allergic comorbidity cluster. Allergy. 2015 Apr 30. doi: 10.1111/all.12640. [Epub ahead of print]

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Image: A child using a peak flow meter which measures how well air moves out (the peak expiratory flow) of a person's lungs when they breath out (exhale). Source (CC): National Heart, Lung and Blood Institute, a division of the National Institute of Health (USA).