Rhinitis, whether allergic or non-allergic, is a powerful predictor of adult-onset asthma. This is the conclusion of an Article in this week's Asthma Special Issue of The Lancet, written by Drs Rafea Shaaban, Mahmoud Zureik, and Bénédicte Leynaert, INSERM Epidemiology Team, Paris, France, and colleagues.
Using data from the European Community Health Survey, the authors investigated the onset of asthma in adult patients aged 20-44 years with allergic and non-allergic rhinitis over 8.8 years. The study analysed 6461 patients from 29 centres in 14 countries mostly in Western Europe, all without ssthma at the beginning of the study. Patients were diagnosed as having rhinitis or not; then their allergic reactions (atopy) were tested by a skin-prick test for house dust mites, cat, two types of fungus, grass, birch, the flowering plant Parietaria, olive, or ragweed. After this, patients were classified into four groups: controls (no atopy, no rhinitis, 3163 patients); atopy only (atopy, no rhinitis, 704); non-allergic rhinitis (rhinitis, no atopy, 1377) and allergic rhinitis (atopy and rhinitis, 1217).
After the 8.8 years, asthma had developed in 1.1% of controls, 1.9% of the atopy only group, 3.1% of the non-allergic rhinitis group and 4.0% of the allergic rhinitis group. The data were then adjusted for country, sex, baseline age, body-mass index, lung capacity, family history of asthma, and smoking. After this, people with allergies only were more than 63% more likely than controls to have asthma; those with non-allergic rhinitis were more than two-and-a-half times more likely to have asthma , and those with allergic rhinitis 3.5 times more likely to have asthma. Only allergic rhinitis with sensitisation to house dust mites was associated with increased risk of asthma independently of other allergens, with a near-trebling of risk. These associations were seen in both men and women.
The authors conclude: "This large prospective study provides strong evidence for an increased risk of asthma in adults with allergic rhinitis, and to a lesser extent non-allergic rhinitis…Several clinical trials in asthmatic patients with allergic rhinitis were associated with a reduction in asthma symptoms. However, only interventional studies could be used to conclude that the treatment of allergic rhinitis is effective in reducing the incidence of asthma."
In an accompanying Comment, Dr Erika von Mutius, University Children's Hospital, Munich, Germany, says: "The idea that allergic rhinitis could cause asthma raises the possibility of preventing asthma by preventing atopic sensation, which could in turn prevent allergic rhinitis." She further discusses how possible treatment strategies for both asthma and allergic rhinitis could affect the symptoms for each other.
Dr Mahmoud Zureik or Bénédicte Leynaert, INSERM (Unit 700, Epidemiology Team), Paris, France T) +33 1 57 27 75 65 E) mahmoud.zureik@inserm.fr
Dr Erika von Mutius, University Children's Hospital, Munich, Germany T) +49 89 5160 7897 E) Erika.von.mutius@med.uni-muenchen.de
Full Article and Comment: http://press.thelancet.com/asthmachildhood.pdf
Journal
The Lancet